Placeholder user services and administration (#8944)

* Adding placeholder user contracts

* Adding create, update, and delete services for placeholder users

* WIP: Adding Placeholder User contract specs [ci skip]

* Extract contract validation into common helper

* Add common validation in BaseContract + common example for admin checks

* Introduce common ModelContract shared context for validations

* WIP: PlaceholderUser controller, i18n, and routes [ci skip]

* Placeholder users index page and query

- moved all group related scopes from User to Principal to make them also available in PlaceholderUser.

* end

* Create PlaceholderUser

* Feature spec for editing a placeholder user

* Manage PlaceholderUser memberships

The managment of memberships is pretty similar for User and PlaceholderUser. This commit extacts the similarities and uses them for both.

* General partial and show view for PlaceholderUser

* Delete obosolete partial

* Allow RequireAdminGuard to be used as a module function

* Fix I18n for confirmation text

* Smaller code improvements

* Fix: Syntax for accessing status enums was wrong.

* Use UpdateService for updating a placeholder user

* Add spec for PlaceholderUsersController

* First code improvements after code review.

- more improvements to come.

* Further code improvements after review

... still more to come

* Correct namespace of delete service

* Fix: Make placeholder user contract validate

* Remove :type attribute from base contract of User and PlaceholerUser

...and add it to the CreateContracts.
Also add type validations.

Further extract shared examples for placeholder user attribute
validation

* Refactor: Extract membership hook calls to helper

* Fix redirect paths for membership controllers

* Specs already present in shared exampels.

* Fix duplicates routes for users and placeholder users

* Fix user path

* Add attribute name and lastname

We don't need a writeable check as both are equally writable

* Replace more references to tab_edit_user_path

* Skip specs for PlaceholderUsers::DeletionService

We will tackle that service in a separate PR.

* Fix module usage of RequireAdminGuard

* Fix group filter for placeholder users

* Fix invalid reference to expect_valid

* Fix: Fix tabbed edit path for placeholder users

* Fix status filtering on users

* Linting

* Improve generalisation of individual principal filter cell

- Check for presence of groups and statuses in order
  to toggle visibility of their UI element.
- Remove groups from placeholder user controller and
  cell initialization and options

* Fix selector on groups assign

* Remove using_shared_fixtures

Co-authored-by: Oliver Günther <mail@oliverguenther.de>

app/cells/individual_principal_base_filter_cell.rb

@@ -0,0 +1,117 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class IndividualPrincipalBaseFilterCell < RailsCell
+  include UsersHelper
+  include ActionView::Helpers::FormOptionsHelper
+
+  class << self
+    def query(params)
+      q = base_query.new
+
+      apply_filters(params, q)
+
+      q
+    end
+
+    def filter(params)
+      query(params).results
+    end
+
+    def filtered?(params)
+      %i(name status group_id role_id).any? { |name| params[name].present? }
+    end
+
+    def filter_name(query, name)
+      if name.present?
+        query.where(:any_name_attribute, '~', name)
+      end
+    end
+
+    def filter_group(query, group_id)
+      if group_id.present?
+        query.where(:group, '=', group_id)
+      end
+    end
+
+    def filter_role(query, role_id)
+      if role_id.present?
+        query.where(:role_id, '=', role_id)
+      end
+    end
+
+    def filter_project(query, project_id)
+      if project_id.present?
+        query.where(:project_id, '=', project_id)
+      end
+    end
+
+    def base_query
+      raise NotImplementedError
+    end
+
+    protected
+
+    def apply_filters(params, query)
+      filter_project query, params[:project_id]
+      filter_name query, params[:name]
+      filter_group query, params[:group_id]
+      filter_role query, params[:role_id]
+
+      query
+    end
+  end
+
+  # INSTANCE METHODS:
+
+  def filter_path
+    raise NotImplementedError
+  end
+
+  def initially_visible?
+    true
+  end
+
+  def has_close_icon?
+    false
+  end
+
+  def has_statuses?
+    defined?(status)
+  end
+
+  def has_groups?
+    defined?(groups) && groups.present?
+  end
+
+  def params
+    model
+  end
+end

app/cells/placeholder_users/placeholder_user_filter_cell.rb

@@ -0,0 +1,47 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class PlaceholderUserFilterCell < IndividualPrincipalBaseFilterCell
+    options :roles, :clear_url, :project
+
+    class << self
+      def base_query
+        Queries::PlaceholderUsers::PlaceholderUserQuery
+      end
+    end
+
+    # INSTANCE METHODS:
+
+    def filter_path
+      placeholder_users_path
+    end
+  end
+end

app/cells/placeholder_users/row_cell.rb

@@ -0,0 +1,58 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class RowCell < ::RowCell
+    include AvatarHelper
+    include UsersHelper
+
+    def placeholder_user
+      model
+    end
+
+    def name
+      link_to h(placeholder_user.name), edit_placeholder_user_path(placeholder_user)
+    end
+
+    def button_links
+      [delete_link].compact
+    end
+
+    def delete_link
+      return nil unless User.current.admin?
+
+      link_to '',
+              placeholder_user_path(placeholder_user),
+              data: { confirm: I18n.t(:text_are_you_sure) },
+              class: 'icon icon-delete',
+              method: :delete
+    end
+  end
+end

app/cells/placeholder_users/table_cell.rb

@@ -0,0 +1,58 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class TableCell < ::TableCell
+    options :current_user # adds this option to those of the base class
+    columns :name, :created_at
+
+    def initial_sort
+      %i[id asc]
+    end
+
+    def headers
+      columns.map do |name|
+        [name.to_s, header_options(name)]
+      end
+    end
+
+    def header_options(name)
+      options = { caption: PlaceholderUser.human_attribute_name(name) }
+
+      options[:default_order] = 'desc' if desc_by_default.include? name
+
+      options
+    end
+
+    def desc_by_default
+      [:created_at]
+    end
+  end
+end

app/cells/user_filter_cell.rb

@@ -1,30 +1,37 @@
-class UserFilterCell < RailsCell
-  include UsersHelper
-  include ActionView::Helpers::FormOptionsHelper
+#-- encoding: UTF-8
 
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class UserFilterCell < IndividualPrincipalBaseFilterCell
   options :groups, :status, :roles, :clear_url, :project
 
   class << self
-    def query(params)
-      q = base_query.new
-
-      filter_project q, params[:project_id]
-      filter_name q, params[:name]
-      filter_status q, status_param(params)
-      filter_group q, params[:group_id]
-      filter_role q, params[:role_id]
-
-      q
-    end
-
-    def filter(params)
-      query(params).results
-    end
-
-    def filtered?(params)
-      %i(name status group_id role_id).any? { |name| params[name].present? }
-    end
-
     ##
     # Returns the selected status from the parameters
     # or the default status to be filtered by (all)
@@ -33,12 +40,6 @@ class UserFilterCell < RailsCell
       params[:status].presence || 'all'
     end
 
-    def filter_name(query, name)
-      if name.present?
-        query.where(:any_name_attribute, '~', name)
-      end
-    end
-
     def filter_status(query, status)
       return unless status && status != 'all'
 
@@ -53,27 +54,19 @@ class UserFilterCell < RailsCell
       end
     end
 
-    def filter_group(query, group_id)
-      if group_id.present?
-        query.where(:group, '=', group_id)
-      end
-    end
-
-    def filter_role(query, role_id)
-      if role_id.present?
-        query.where(:role_id, '=', role_id)
-      end
-    end
-
-    def filter_project(query, project_id)
-      if project_id.present?
-        query.where(:project_id, '=', project_id)
-      end
-    end
-
     def base_query
       Queries::Users::UserQuery
     end
+
+
+    protected
+
+    def apply_filters(params, query)
+      super(params, query)
+      filter_status query, status_param(params)
+
+      query
+    end
   end
 
   # INSTANCE METHODS:
@@ -82,18 +75,6 @@ class UserFilterCell < RailsCell
     users_path
   end
 
-  def initially_visible?
-    true
-  end
-
-  def has_close_icon?
-    false
-  end
-
-  def params
-    model
-  end
-
   def user_status_options
     users_status_options_for_select status, extra: extra_user_status_options
   end

app/cells/users/user_filter_cell.rb

@@ -1,3 +1,33 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
 module Users
   class UserFilterCell < ::UserFilterCell
     def filter_role(query, role_id)

app/cells/views/individual_principal_base_filter/show.erb

@@ -37,11 +37,13 @@ See docs/COPYRIGHT.rdoc for more details.
       </a>
     <% end %>
     <ul class="simple-filters--filters">
-      <li class="simple-filters--filter">
+      <% if has_statuses? %>
+        <li class="simple-filters--filter">
           <label class='simple-filters--filter-name' for='status'><%= User.human_attribute_name(:status) %>:</label>
           <%= select_tag 'status', user_status_options, class: 'simple-filters--filter-value' %>
-      </li>
-      <% if groups.present? %>
+        </li>
+      <% end %>
+      <% if has_groups? %>
         <li class="simple-filters--filter">
           <label class='simple-filters--filter-name' for='group_id'><%= Group.model_name.human %>:</label>
           <%= collection_select :group,

app/contracts/attribute_help_texts/base_contract.rb

@@ -30,10 +30,9 @@
 
 module AttributeHelpTexts
   class BaseContract < ::ModelContract
+    include RequiresAdminGuard
     include Attachments::ValidateReplacements
 
-    validate :validate_user_allowed_to_manage
-
     def self.model
       AttributeHelpText
     end
@@ -41,9 +40,5 @@ module AttributeHelpTexts
     attribute :type
     attribute :attribute_name
     attribute :help_text
-
-    def validate_user_allowed_to_manage
-      errors.add :base, :error_unauthorized unless user.admin?
-    end
   end
 end

app/contracts/concerns/requires_admin_guard.rb

@@ -32,12 +32,14 @@ module RequiresAdminGuard
   extend ActiveSupport::Concern
 
   included do
-    validate :validate_admin_only
+    validate { validate_admin_only(user, errors) }
+  end
 
-    def validate_admin_only
-      unless user.admin?
-        errors.add :base, :error_unauthorized
-      end
+  module_function
+
+  def validate_admin_only(user, errors)
+    unless user.admin? && user.active?
+      errors.add :base, :error_unauthorized
     end
   end
 end

app/contracts/delete_contract.rb

@@ -56,7 +56,7 @@ class DeleteContract < ModelContract
 
     case permission
     when :admin
-      user.admin?
+      user.admin? && user.active?
     when Proc
       instance_exec(&permission)
     else

app/contracts/placeholder_users/base_contract.rb

@@ -0,0 +1,55 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class BaseContract < ::ModelContract
+    # attribute_alias is broken in the sense
+    # that `model#changed` includes only the non-aliased name
+    # hence we need to put "lastname" as an attribute here
+    attribute :name
+    attribute :lastname
+
+    def self.model
+      PlaceholderUser
+    end
+
+    validate :user_allowed_to_modify
+
+    protected
+
+    ##
+    # Placeholder users can only be updated by Admins
+    def user_allowed_to_modify
+      unless user.admin? && user.active?
+        errors.add :base, :error_unauthorized
+      end
+    end
+  end
+end

app/contracts/placeholder_users/create_contract.rb

@@ -0,0 +1,45 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class CreateContract < BaseContract
+    attribute :type
+
+    validate :type_is_placeholder_user
+
+    private
+
+    def type_is_placeholder_user
+      unless model.type == PlaceholderUser.name
+        errors.add(:type, 'Type and class mismatch')
+      end
+    end
+  end
+end

app/contracts/placeholder_users/delete_contract.rb

@@ -0,0 +1,59 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class DeleteContract < ::DeleteContract
+    delete_permission -> {
+      self.class.deletion_allowed?(user)
+    }
+
+    ##
+    # Checks if a given user may be deleted by another one.
+    #
+    # @param actor [User] User who wants to delete the given placeholder user.
+    def self.deletion_allowed?(actor)
+      actor.admin? && actor.active?
+    end
+
+    protected
+
+    ##
+    # PlaceholderUsers can only be deleted by Admins
+    def user_allowed_to_modify
+      unless deletion_allowed?
+        errors.add :base, :error_unauthorized
+      end
+    end
+
+    def deletion_allowed?
+      self.class.deletion_allowed? user
+    end
+  end
+end

app/contracts/placeholder_users/update_contract.rb

@@ -0,0 +1,34 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class UpdateContract < BaseContract
+  end
+end

app/contracts/projects/archive_contract.rb

@@ -28,9 +28,9 @@
 
 module Projects
   class ArchiveContract < ModelContract
+    include RequiresAdminGuard
     include Projects::Archiver
 
-    validate :validate_admin_only
     validate :validate_no_foreign_wp_references
 
     protected

app/contracts/projects/archiver.rb

@@ -28,12 +28,6 @@
 
 module Projects
   module Archiver
-    def validate_admin_only
-      unless user.admin?
-        errors.add :base, :error_unauthorized
-      end
-    end
-
     # Check that there is no wp of a non descendant project that is assigned
     # to one of the project or descendant versions
     def validate_no_foreign_wp_references

app/contracts/projects/base_contract.rb

@@ -135,7 +135,7 @@ module Projects
     def validate_changing_active
       return unless model.active_changed?
 
-      validate_admin_only
+      RequiresAdminGuard.validate_admin_only(user, errors)
 
       if model.active?
         # switched to active -> unarchiving

app/contracts/projects/unarchive_contract.rb

@@ -28,9 +28,9 @@
 
 module Projects
   class UnarchiveContract < ModelContract
+    include RequiresAdminGuard
     include Projects::Archiver
 
-    validate :validate_admin_only
     validate :validate_all_ancestors_active
 
     protected

app/contracts/users/base_contract.rb

@@ -28,11 +28,8 @@
 # See docs/COPYRIGHT.rdoc for more details.
 #++
 
-require 'model_contract'
-
 module Users
   class BaseContract < ::ModelContract
-    attribute :type
     attribute :login
     attribute :firstname
     attribute :lastname

app/contracts/users/create_contract.rb

@@ -28,10 +28,10 @@
 # See docs/COPYRIGHT.rdoc for more details.
 #++
 
-require 'users/base_contract'
-
 module Users
   class CreateContract < BaseContract
+    attribute :type
+
     attribute :status do
       unless model.active? || model.invited?
         # New users may only have these two statuses
@@ -41,6 +41,7 @@ module Users
 
     validate :user_allowed_to_add
     validate :authentication_defined
+    validate :type_is_user
 
     private
 
@@ -59,5 +60,11 @@ module Users
         errors.add :base, :error_unauthorized
       end
     end
+
+    def type_is_user
+      unless model.type == User.name
+        errors.add(:type, 'Type and class mismatch')
+      end
+    end
   end
 end

app/contracts/users/delete_contract.rb

@@ -28,8 +28,6 @@
 # See docs/COPYRIGHT.rdoc for more details.
 #++
 
-require 'users/base_contract'
-
 module Users
   class DeleteContract < ::DeleteContract
     delete_permission -> {

app/contracts/users/update_contract.rb

@@ -28,8 +28,6 @@
 # See docs/COPYRIGHT.rdoc for more details.
 #++
 
-require 'users/base_contract'
-
 module Users
   class UpdateContract < BaseContract
     validate :user_allowed_to_update

app/controllers/messages_controller.rb

@@ -67,7 +67,7 @@ class MessagesController < ApplicationController
     @message = Messages::SetAttributesService
       .new(user: current_user,
            model: Message.new,
-           contract_class: NoopContract)
+           contract_class: EmptyContract)
       .call(forum: @forum)
       .result
   end

app/controllers/placeholder_users/memberships_controller.rb

@@ -0,0 +1,47 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class PlaceholderUsers::MembershipsController < ApplicationController
+  include IndividualPrincipals::MembershipControllerMethods
+  layout 'admin'
+
+  before_action :require_admin
+  before_action :find_individual_principal
+
+  def find_individual_principal
+    @individual_principal = PlaceholderUser.find(params[:placeholder_user_id])
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+
+  def redirected_to_tab(_membership)
+    'memberships'
+  end
+end

app/controllers/placeholder_users_controller.rb

@@ -0,0 +1,162 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class PlaceholderUsersController < ApplicationController
+  layout 'admin'
+
+  helper_method :gon
+
+  before_action :require_admin, except: [:show]
+  before_action :find_placeholder_user, only: %i[show
+                                                 edit
+                                                 update
+                                                 destroy]
+  before_action :check_if_deletion_allowed, only: [:destroy]
+
+  def index
+    @placeholder_users = PlaceholderUsers::PlaceholderUserFilterCell.filter params
+
+    respond_to do |format|
+      format.html do
+        render layout: !request.xhr?
+      end
+    end
+  end
+
+  def show
+    # show projects based on current user visibility
+    @memberships = @placeholder_user.memberships
+                        .visible(current_user)
+
+    respond_to do |format|
+      format.html { render layout: 'no_menu' }
+    end
+  end
+
+  def new
+    @placeholder_user = PlaceholderUsers::SetAttributesService
+                          .new(user: User.current,
+                               model: PlaceholderUser.new,
+                               contract_class: EmptyContract)
+                          .call({})
+                          .result
+  end
+
+  def create
+    service = PlaceholderUsers::CreateService.new(user: User.current)
+    service_result = service.call(permitted_params.placeholder_user)
+    @placeholder_user = service_result.result
+
+    if service_result.success?
+      respond_to do |format|
+        format.html do
+          flash[:notice] = I18n.t(:notice_successful_create)
+          redirect_to(params[:continue] ? new_placeholder_user_path : edit_placeholder_user_path(@placeholder_user))
+        end
+      end
+    else
+      respond_to do |format|
+        format.html do
+          render action: :new
+        end
+      end
+    end
+  end
+
+  def edit
+    @membership ||= Member.new
+    @individual_principal = @placeholder_user
+  end
+
+  def update
+    service_result = PlaceholderUsers::UpdateService
+                       .new(user: User.current,
+                            model: @placeholder_user)
+                       .call(permitted_params.placeholder_user)
+
+    if service_result.success?
+      respond_to do |format|
+        format.html do
+          flash[:notice] = I18n.t(:notice_successful_update)
+          redirect_back(fallback_location: edit_placeholder_user_path(@placeholder_user))
+        end
+      end
+    else
+      @membership ||= Member.new
+
+      respond_to do |format|
+        format.html do
+          render action: :edit
+        end
+      end
+    end
+  end
+
+  def destroy
+    Users::DeleteService.new(user: User.current,
+                             model: @placeholder_user)
+                        .call
+
+    flash[:notice] = I18n.t('account.deleted')
+
+    respond_to do |format|
+      format.html do
+        redirect_to placeholder_users_path
+      end
+    end
+  end
+
+  private
+
+  def find_placeholder_user
+    @placeholder_user = PlaceholderUser.find(params[:id])
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+
+  def check_if_deletion_allowed
+    render_404 unless PlaceholderUsers::DeleteService.deletion_allowed? @placeholder_user, User.current
+  end
+
+  protected
+
+  def default_breadcrumb
+    if action_name == 'index'
+      t('label_placeholder_user_plural')
+    else
+      ActionController::Base.helpers.link_to(t('label_placeholder_user_plural'),
+                                             placeholder_users_path)
+    end
+  end
+
+  def show_local_breadcrumb
+    current_user.admin?
+  end
+end

app/controllers/users/memberships_controller.rb

@@ -29,56 +29,14 @@
 #++
 
 class Users::MembershipsController < ApplicationController
+  include IndividualPrincipals::MembershipControllerMethods
   layout 'admin'
 
   before_action :require_admin
-  before_action :find_user
+  before_action :find_individual_principal
 
-  def update
-    update_or_create(request.patch?, :notice_successful_update)
-  end
-
-  def create
-    update_or_create(request.post?, :notice_successful_create)
-  end
-
-  def destroy
-    @membership = @user.memberships.find(params[:id])
-    tab = redirected_to_tab(@membership)
-
-    if @membership.deletable? && request.delete?
-      @membership.destroy
-      @membership = nil
-
-      flash[:notice] = I18n.t(:notice_successful_delete)
-    end
-
-    redirect_to controller: '/users', action: 'edit', id: @user, tab: tab
-  end
-
-  private
-
-  def update_or_create(save_record, message)
-    @membership = params[:id].present? ? Member.find(params[:id]) : Member.new(principal: @user, project: nil)
-
-    result = ::Members::EditMembershipService
-             .new(@membership, save: save_record, current_user: current_user)
-             .call(attributes: permitted_params.membership)
-
-    if result.success?
-      flash[:notice] = I18n.t(message)
-    else
-      flash[:error] = result.errors.full_messages.join("\n")
-    end
-
-    redirect_to controller: '/users',
-                action: 'edit',
-                id: @user,
-                tab: redirected_to_tab(@membership)
-  end
-
-  def find_user
-    @user = User.find(params[:user_id])
+  def find_individual_principal
+    @individual_principal = User.find(params[:user_id])
   rescue ActiveRecord::RecordNotFound
     render_404
   end

app/controllers/users_controller.rb

@@ -126,6 +126,7 @@ class UsersController < ApplicationController
   def edit
     @auth_sources = AuthSource.all
     @membership ||= Member.new
+    @individual_principal = @user
   end
 
   def update

app/helpers/individual_principal_hooks_helper.rb

@@ -0,0 +1,40 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module IndividualPrincipalHooksHelper
+  def call_individual_principals_memberships_hook(individual_principal, suffix, context = {})
+    call_context = { individual_principal_key(individual_principal) => individual_principal }.merge(context)
+    call_hook("view_#{individual_principal.class.name.underscore.pluralize}_memberships_table_#{suffix}".to_sym, call_context)
+  end
+
+  def individual_principal_key(individual_principal)
+    individual_principal.class.name.underscore.to_sym
+  end
+end

app/models/permitted_params.rb

@@ -183,6 +183,10 @@ class PermittedParams
     permitted_params.merge(custom_field_values(:user))
   end
 
+  def placeholder_user
+    params.require(:placeholder_user).permit(*self.class.permitted_attributes[:placeholder_user])
+  end
+
   def my_account_settings
     user.merge(pref: pref)
   end
@@ -525,6 +529,9 @@ class PermittedParams
           :client_credentials_user_id,
           { scopes: [] }
         ],
+        placeholder_user: %i(
+          name
+        ),
         project_type: [
           :name,
           { type_ids: [] }

app/models/placeholder_user.rb

@@ -33,6 +33,7 @@ class PlaceholderUser < Principal
 
   validates_presence_of(:name)
   validates_uniqueness_of(:name)
+  validates_length_of :name, maximum: 256
 
   include ::Associations::Groupable
 

app/models/principal.rb

@@ -76,6 +76,31 @@ class Principal < ApplicationRecord
   scope :not_in_project, ->(project) {
     where.not(id: Member.of(project).select(:user_id))
   }
+  
+  scope :in_group, ->(group) {
+    within_group(group)
+  }
+
+  scope :not_in_group, ->(group) {
+    within_group(group, false)
+  }
+
+  scope :within_group, ->(group, positive = true) {
+    group_id = group.is_a?(Group) ? [group.id] : Array(group).map(&:to_i)
+
+    sql_condition = group_id.any? ? 'WHERE gu.group_id IN (?)' : ''
+    sql_not = positive ? '' : 'NOT'
+
+    sql_query = [
+      "#{User.table_name}.id #{sql_not} IN " \
+      "(SELECT gu.user_id FROM #{table_name_prefix}group_users#{table_name_suffix} gu #{sql_condition})"
+    ]
+    if group_id.any?
+      sql_query.push group_id
+    end
+
+    where(sql_query)
+  }
 
   before_create :set_default_empty_values
 

app/models/queries/individual_principals/orders/group_order.rb

@@ -0,0 +1,50 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::IndividualPrincipals::Orders::GroupOrder < Queries::BaseOrder
+  self.model = Principal
+
+  def self.key
+    :group
+  end
+
+  private
+
+  def order
+    order_string = "groups_users.lastname"
+
+    order_string += " DESC" if direction == :desc
+
+    model.order(order_string)
+  end
+
+  def joins
+    :groups
+  end
+end

app/models/queries/individual_principals/orders/name_order.rb

@@ -0,0 +1,49 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::IndividualPrincipals::Orders::NameOrder < Queries::BaseOrder
+  self.model = Principal
+
+  def self.key
+    :name
+  end
+
+  private
+
+  def order
+    ordered = model.order_by_name
+
+    if direction == :desc
+      ordered = ordered.reverse_order
+    end
+
+    ordered
+  end
+end

app/models/queries/placeholder_users.rb

@@ -0,0 +1,49 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module Queries::PlaceholderUsers
+  Queries::Register.filter Queries::PlaceholderUsers::PlaceholderUserQuery,
+                           Queries::PlaceholderUsers::Filters::NameFilter
+
+  Queries::Register.filter Queries::PlaceholderUsers::PlaceholderUserQuery,
+                           Queries::PlaceholderUsers::Filters::AnyNameAttributeFilter
+
+  Queries::Register.filter Queries::PlaceholderUsers::PlaceholderUserQuery,
+                           Queries::PlaceholderUsers::Filters::GroupFilter
+
+  Queries::Register.order Queries::PlaceholderUsers::PlaceholderUserQuery,
+                          Queries::PlaceholderUsers::Orders::DefaultOrder
+
+  Queries::Register.order Queries::PlaceholderUsers::PlaceholderUserQuery,
+                          Queries::PlaceholderUsers::Orders::NameOrder
+
+  Queries::Register.order Queries::PlaceholderUsers::PlaceholderUserQuery,
+                          Queries::PlaceholderUsers::Orders::GroupOrder
+end

app/models/queries/placeholder_users/filters/any_name_attribute_filter.rb

@@ -0,0 +1,33 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Filters::AnyNameAttributeFilter < Queries::PlaceholderUsers::Filters::NameFilter
+  include Queries::Filters::Shared::AnyUserNameAttributeFilter
+end

app/models/queries/placeholder_users/filters/group_filter.rb

@@ -0,0 +1,49 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Filters::GroupFilter < Queries::PlaceholderUsers::Filters::PlaceholderUserFilter
+  include Queries::Filters::Shared::GroupFilter
+
+  self.model = PlaceholderUser
+
+  def human_name
+    PlaceholderUser.human_attribute_name(name)
+  end
+
+  private
+
+  def group_subselect
+    PlaceholderUser.in_group(values).select(:id).to_sql
+  end
+
+  def any_group_subselect
+    PlaceholderUser.within_group([]).select(:id).to_sql
+  end
+end

app/models/queries/placeholder_users/filters/name_filter.rb

@@ -0,0 +1,33 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Filters::NameFilter < Queries::PlaceholderUsers::Filters::PlaceholderUserFilter
+  include Queries::Filters::Shared::UserNameFilter
+end

app/models/queries/placeholder_users/filters/placeholder_user_filter.rb

@@ -0,0 +1,37 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Filters::PlaceholderUserFilter < Queries::Filters::Base
+  self.model = PlaceholderUser
+
+  def human_name
+    User.human_attribute_name(name)
+  end
+end

app/models/queries/placeholder_users/orders/default_order.rb

@@ -0,0 +1,37 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Orders::DefaultOrder < Queries::BaseOrder
+  self.model = PlaceholderUser
+
+  def self.key
+    /\A(id|name)\z/
+  end
+end

app/models/queries/placeholder_users/orders/group_order.rb

@@ -0,0 +1,33 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Orders::GroupOrder < Queries::IndividualPrincipals::Orders::GroupOrder
+  self.model = PlaceholderUser
+end

app/models/queries/placeholder_users/orders/name_order.rb

@@ -0,0 +1,33 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::Orders::NameOrder < Queries::IndividualPrincipals::Orders::NameOrder
+  self.model = PlaceholderUser
+end

app/models/queries/placeholder_users/placeholder_user_query.rb

@@ -0,0 +1,35 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::PlaceholderUsers::PlaceholderUserQuery < Queries::BaseQuery
+  def self.model
+    PlaceholderUser
+  end
+end

app/models/queries/users/orders/group_order.rb

@@ -28,24 +28,6 @@
 # See docs/COPYRIGHT.rdoc for more details.
 #++
 
-class Queries::Users::Orders::GroupOrder < Queries::BaseOrder
+class Queries::Users::Orders::GroupOrder < Queries::IndividualPrincipals::Orders::GroupOrder
   self.model = User
-
-  def self.key
-    :group
-  end
-
-  private
-
-  def order
-    order_string = "groups_users.lastname"
-
-    order_string += " DESC" if direction == :desc
-
-    model.order(order_string)
-  end
-
-  def joins
-    :groups
-  end
 end

app/models/user.rb

@@ -137,26 +137,6 @@ class User < Principal
   before_destroy :delete_associated_private_queries
   before_destroy :reassign_associated
 
-  scope :in_group, ->(group) {
-    within_group(group)
-  }
-  scope :not_in_group, ->(group) {
-    within_group(group, false)
-  }
-  scope :within_group, ->(group, positive = true) {
-    group_id = group.is_a?(Group) ? [group.id] : Array(group).map(&:to_i)
-
-    sql_condition = group_id.any? ? 'WHERE gu.group_id IN (?)' : ''
-    sql_not = positive ? '' : 'NOT'
-
-    sql_query = ["#{User.table_name}.id #{sql_not} IN (SELECT gu.user_id FROM #{table_name_prefix}group_users#{table_name_suffix} gu #{sql_condition})"]
-    if group_id.any?
-      sql_query.push group_id
-    end
-
-    where(sql_query)
-  }
-
   scope :admin, -> { where(admin: true) }
 
   def self.unique_attribute

app/services/placeholder_users/create_service.rb

@@ -0,0 +1,32 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class PlaceholderUsers::CreateService < ::BaseServices::Create
+end

app/services/placeholder_users/delete_service.rb

@@ -0,0 +1,32 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class PlaceholderUsers::DeleteService < ::BaseServices::Delete
+end

app/services/placeholder_users/set_attributes_service.rb

@@ -0,0 +1,34 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+module PlaceholderUsers
+  class SetAttributesService < ::BaseServices::SetAttributes
+  end
+end

app/services/placeholder_users/update_service.rb

@@ -0,0 +1,32 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class PlaceholderUsers::UpdateService < ::BaseServices::Update
+end

app/views/individual_principals/_memberships.html.erb

@@ -6,7 +6,7 @@ This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License version 3.
 
 OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
-Copyright (C) 2006-2013 Jean-Philippe Lang
+Copyright (C) 2006-2017 Jean-Philippe Lang
 Copyright (C) 2010-2013 the ChiliProject Team
 
 This program is free software; you can redistribute it and/or
@@ -31,14 +31,14 @@ See docs/COPYRIGHT.rdoc for more details.
 
 <div class="grid-block">
   <div class="grid-content">
-  <% if @user.memberships.any? %>
+  <% if @individual_principal.memberships.any? %>
     <div class="generic-table--container">
       <div class="generic-table--results-container">
         <table class="generic-table memberships">
           <colgroup>
             <col highlight-col>
             <col highlight-col>
-            <%= call_hook(:view_users_memberships_table_colgroup, user: @user )%>
+            <%= call_individual_principals_memberships_hook(@individual_principal, 'colgroup') %>
             <col>
           </colgroup>
           <thead>
@@ -61,12 +61,12 @@ See docs/COPYRIGHT.rdoc for more details.
                   </div>
                 </div>
               </th>
-              <%= call_hook(:view_users_memberships_table_header, user: @user )%>
+              <%= call_individual_principals_memberships_hook(@individual_principal, 'header') %>
               <th><div class="generic-table--empty-header"></div></th>
             </tr>
           </thead>
           <tbody>
-            <% @user.memberships.where.not(project: nil).each do |membership| %>
+            <% @individual_principal.memberships.where.not(project: nil).each do |membership| %>
               <% next if membership.new_record? %>
                 <tr id="member-<%= membership.id %>" class="member">
                   <td class="project">
@@ -78,7 +78,7 @@ See docs/COPYRIGHT.rdoc for more details.
                       <%=h membership.roles.sort.collect(&:to_s).join(', ') %>
                     </span>
                     <%= labelled_tabular_form_for(:membership,
-                                                  url: user_membership_path(user_id: @user, id: membership),
+                                                  url: polymorphic_path([@individual_principal, :membership], id: membership),
                                                   html: { id: "member-#{membership.id}-roles-form",
                                                           class: "member-#{membership.id}--edit-toggle-item",
                                                           style: 'display:none;'},
@@ -98,20 +98,24 @@ See docs/COPYRIGHT.rdoc for more details.
                             </label>
                         <% end %>
                       </div>
-                      <p><%= submit_tag t(:button_change), class: 'user-memberships--edit-submit-button button -highlight -small' %>
+                      <p><%= submit_tag t(:button_change), class: 'memberships--edit-submit-button button -highlight -small' %>
                         <%= link_to_function t(:button_cancel),
                                              "jQuery('.member-#{membership.id}--edit-toggle-item').toggle();",
                   class: 'button -small' %></p>
                     <% end %>
                   </td>
-                  <%= call_hook(:view_users_memberships_table_row, user: @user, membership: membership, roles: roles, projects: projects )%>
+                  <%= call_individual_principals_memberships_hook(@individual_principal,
+                                                                 'row',
+                                                                 membership: membership,
+                                                                 roles: roles,
+                                                                 projects: projects) %>
                   <td class="buttons">
                     <%= link_to_function icon_wrapper('icon icon-edit', t(:button_edit)),
                                          "jQuery('.member-#{membership.id}--edit-toggle-item').toggle();",
-                                         class: "member-#{membership.id}--edit-toggle-item user-memberships--edit-button",
+                                         class: "member-#{membership.id}--edit-toggle-item memberships--edit-button",
                                          title: t(:button_edit) %>
                     <%= link_to(icon_wrapper('icon icon-remove', t(:button_remove)),
-                                user_membership_path(user_id: @user, id: membership),
+                                polymorphic_path([@individual_principal, :membership], id: membership),
                                 method: :delete,
                                 title: t(:button_remove)) if membership.deletable? %>
                   </td>
@@ -129,11 +133,11 @@ See docs/COPYRIGHT.rdoc for more details.
   <div class="grid-content">
     <% if projects.any? %>
       <%= labelled_tabular_form_for(:membership,
-                                    url: user_memberships_path(user_id: @user),
+                                    url: polymorphic_path([@individual_principal, :memberships]),
                                     html: {id: "new_project_membership"}) do %>
         <fieldset class="form--fieldset">
           <legend class="form--fieldset-legend"><%=t(:label_project_new)%></legend>
-          <%= styled_select_tag 'membership[project_id]', options_for_membership_project_select(@user, projects) %>
+          <%= styled_select_tag 'membership[project_id]', options_for_membership_project_select(@individual_principal, projects) %>
           <div class="form--field -vertical">
             <%= styled_label_tag nil, "#{t(:label_role_plural)}:" %>
             <div class="form--field-container -vertical">

app/views/placeholder_users/_form.html.erb

@@ -0,0 +1,38 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2020 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2017 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+
+<%= error_messages_for 'placeholder_user' %>
+
+<!--[form:placeholder_user]-->
+<section class="form--section">
+  <div class="form--field -required"><%= f.text_field :name, label: t('label_name'),  required: true, container_class: '-middle' %></div>
+
+  <%= call_hook(:view_placeholder_users_form, placeholder_user: @placeholder_user, form: f) %>
+</section>
+<!--[eoform:placeholder_user]-->

app/views/placeholder_users/_general.html.erb

@@ -0,0 +1,40 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2020 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2017 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+
+<%= labelled_tabular_form_for @placeholder_user,
+                              url: { controller: '/placeholder_users',
+                                     action: "update",
+                                     tab: nil },
+                              html: { method: :put,
+                                      autocomplete: 'off' },
+                              as: :placeholder_user do |f| %>
+  <%= render partial: 'form', locals: { f: f } %>
+
+  <%= styled_button_tag t(:button_save), class: '-highlight -with-icon icon-checkmark' %>
+<% end %>

app/views/placeholder_users/_toolbar.html.erb

@@ -0,0 +1,38 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2021 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2013 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+<%= breadcrumb_toolbar(@placeholder_user.new_record? ? t(:label_placeholder_user_new) : @placeholder_user.name) do %>
+  <% unless @placeholder_user.new_record? %>
+  <li class="toolbar-item">
+    <%= link_to placeholder_user_path(@placeholder_user), class: 'button' do %>
+      <%= op_icon('button--icon icon-user') %>
+      <span class="button--text"><%= t(:label_profile) %></span>
+    <% end %>
+  </li>
+  <% end %>
+<% end %>

app/views/placeholder_users/edit.html.erb

@@ -0,0 +1,36 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2020 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2017 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+
+
+<% html_title(t(:label_administration), "#{t(:label_edit)} #{PlaceholderUser.model_name.human} #{h(@placeholder_user.name)}") -%>
+
+<% local_assigns[:additional_breadcrumb] = @placeholder_user.name %>
+<%= render partial: 'toolbar', locals: { new_user: false, :@placeholder_user => @placeholder_user } %>
+
+<%= render_extensible_tabs :placeholder_user, placeholder_user: @placeholder_user %>

app/views/placeholder_users/index.html.erb

@@ -0,0 +1,46 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2020 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2017 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+<% html_title t(:label_administration), t(:label_placeholder_user_plural) -%>
+
+<%= toolbar title: t(:label_placeholder_user_plural), title_class: 'no-padding-bottom' do %>
+  <li class="toolbar-item">
+    <%= link_to new_placeholder_user_path,
+                { class: 'button -alt-highlight',
+                  aria: { label: t(:label_placeholder_user_new) },
+                  title: t(:label_placeholder_user_new) } do %>
+      <%= op_icon('button--icon icon-add') %>
+      <span class="button--text"><%= t('activerecord.models.placeholder_user') %></span>
+    <% end %>
+  </li>
+  <%= call_hook(:placeholder_user_admin_action_menu) %>
+<% end %>
+
+<%= cell PlaceholderUsers::PlaceholderUserFilterCell, params %>
+&nbsp;
+<%= cell PlaceholderUsers::TableCell, @placeholder_users, project: @project, current_user: current_user %>

app/views/placeholder_users/new.html.erb

@@ -0,0 +1,44 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2020 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2017 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+
+<% html_title t(:label_administration), t("label_placeholder_user_new") %>
+<% local_assigns[:additional_breadcrumb] = t(:label_placeholder_user_new) %>
+<%= render partial: 'toolbar', locals: { new_user: true,
+                                         :@placeholder_user => @placeholder_user } %>
+<%= labelled_tabular_form_for @placeholder_user,
+                              url: { action: "create" },
+                              html: { class: nil, autocomplete: 'off' },
+                              as: :placeholder_user do |f| %>
+  <%= render partial: 'form', locals: { f: f, placeholder_user: @placeholder_user } %>
+
+  <p>
+    <%= styled_button_tag t(:button_create), class: '-highlight -with-icon icon-checkmark' %>
+    <%= styled_button_tag t(:button_create_and_continue), name: 'continue', class: '-highlight -with-icon icon-checkmark' %>
+  </p>
+<% end %>

app/views/placeholder_users/show.html.erb

@@ -0,0 +1,66 @@
+<%#-- copyright
+OpenProject is an open source project management software.
+Copyright (C) 2012-2021 the OpenProject GmbH
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License version 3.
+
+OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+Copyright (C) 2006-2013 Jean-Philippe Lang
+Copyright (C) 2010-2013 the ChiliProject Team
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+See docs/COPYRIGHT.rdoc for more details.
+
+++#%>
+
+<% content_for :header_tags do %>
+  <%= call_hook :placeholder_users_show_head %>
+<% end %>
+<% html_title t(:label_administration), t(:label_placeholder_user_plural) -%>
+<%= toolbar title: "#{avatar @placeholder_user} #{h(@placeholder_user.name)}".html_safe do %>
+  <% if User.current.admin? %>
+    <li class="toolbar-item">
+      <%= link_to edit_placeholder_user_path(@placeholder_user), class: 'button', accesskey: accesskey(:edit) do %>
+        <%= op_icon('button--icon icon-edit') %>
+        <span class="button--text"><%= t(:button_edit) %></span>
+      <% end %>
+    </li>
+  <% end %>
+<% end %>
+
+<div class="grid-block medium-up-2">
+  <div class="grid-content">
+    <%= call_hook :view_account_left_top, placeholder_user: @placeholder_user %>
+
+    <%= call_hook :view_account_left_middle, placeholder_user: @placeholder_user %>
+
+    <% unless @memberships.empty? %>
+      <h3><%=t(:label_project_plural)%></h3>
+      <ul>
+        <% for membership in @memberships %>
+          <li>
+            <%= link_to_project(membership.project) %>
+            (<%=h membership.roles.sort.collect(&:to_s).join(', ') %>, <%= format_date(membership.created_at) %>)
+          </li>
+        <% end %>
+      </ul>
+    <% end %>
+    <%= call_hook :view_account_left_bottom, placeholder_user: @placeholder_user %>
+  </div>
+</div>
+
+<% html_title h(@placeholder_user.name) %>

app/views/users/index.html.erb

@@ -44,8 +44,8 @@ See docs/COPYRIGHT.rdoc for more details.
   <li class="toolbar-item">
     <%= link_to new_user_path,
         { class: 'button -alt-highlight',
-          aria: {label: t(:label_user_new)},
-          title: t(:label_user_new)} do %>
+          aria: { label: t(:label_user_new) },
+          title: t(:label_user_new) } do %>
       <%= op_icon('button--icon icon-add') %>
       <span class="button--text"><%= t('activerecord.models.user') %></span>
     <% end %>

config/initializers/menus.rb

@@ -155,6 +155,11 @@ Redmine::MenuManager.map :admin_menu do |menu|
             caption: :label_user_plural,
             parent: :users_and_permissions
 
+  menu.push :placeholder_users,
+            { controller: '/placeholder_users' },
+            caption: :label_placeholder_user_plural,
+            parent: :users_and_permissions
+
   menu.push :groups,
             { controller: '/groups' },
             if: Proc.new { User.current.admin? },

config/locales/en.yml

@@ -774,6 +774,7 @@ en:
       status: "Work package status"
       member: "Member"
       news: "News"
+      placeholder_user: "Placeholder user"
       project: "Project"
       query: "Custom query"
       role:
@@ -1535,6 +1536,7 @@ en:
   label_my_account_data: "My account data"
   label_my_projects: "My projects"
   label_my_queries: "My custom queries"
+  label_name: "Name"
   label_never: "Never"
   label_new: "New"
   label_new_features: "New features"
@@ -1584,6 +1586,9 @@ en:
   label_permissions: "Permissions"
   label_permissions_report: "Permissions report"
   label_personalize_page: "Personalize this page"
+  label_placeholder_user: "Placeholder user"
+  label_placeholder_user_new: "New placeholder user"
+  label_placeholder_user_plural: "Placeholder users"
   label_planning: "Planning"
   label_please_login: "Please log in"
   label_plugins: "Plugins"

config/routes.rb

@@ -452,11 +452,11 @@ OpenProject::Application.routes.draw do
 
   resources :activity, :activities, only: :index, controller: 'activities'
 
-  resources :users do
+  resources :users, except: :edit do
     resources :memberships, controller: 'users/memberships', only: %i[update create destroy]
 
     member do
-      match '/edit/:tab' => 'users#edit', via: :get, as: 'tab_edit'
+      get '/edit(/:tab)' => 'users#edit', as: 'edit'
       match '/change_status/:change_action' => 'users#change_status_info', via: :get, as: 'change_status_info'
       post :change_status
       post :resend_invitation
@@ -464,6 +464,14 @@ OpenProject::Application.routes.draw do
     end
   end
 
+  resources :placeholder_users, except: :edit do
+    resources :memberships, controller: 'placeholder_users/memberships', only: %i[update create destroy]
+
+    member do
+      get '/edit(/:tab)' => 'placeholder_users#edit', as: 'edit'
+    end
+  end
+
   # The show page of groups is public and thus moved out of the admin scope
   resources :groups, only: %i[show], as: :show_group
 

lib/individual_principals/membership_controller_methods.rb

@@ -0,0 +1,43 @@
+module IndividualPrincipals
+  module MembershipControllerMethods
+    def update
+      update_or_create(request.patch?, :notice_successful_update)
+    end
+
+    def create
+      update_or_create(request.post?, :notice_successful_create)
+    end
+
+    def destroy
+      @membership = @individual_principal.memberships.find(params[:id])
+      tab = redirected_to_tab(@membership)
+
+      if @membership.deletable? && request.delete?
+        @membership.destroy
+        @membership = nil
+
+        flash[:notice] = I18n.t(:notice_successful_delete)
+      end
+
+      redirect_to edit_polymorphic_path(@individual_principal, tab: tab)
+    end
+
+    private
+
+    def update_or_create(save_record, message)
+      @membership = params[:id].present? ? Member.find(params[:id]) : Member.new(principal: @individual_principal, project: nil)
+
+      result = ::Members::EditMembershipService
+                   .new(@membership, save: save_record, current_user: current_user)
+                   .call(attributes: permitted_params.membership)
+
+      if result.success?
+        flash[:notice] = I18n.t(message)
+      else
+        flash[:error] = result.errors.full_messages.join("\n")
+      end
+
+      redirect_to edit_polymorphic_path(@individual_principal, tab: redirected_to_tab(@membership))
+    end
+  end
+end

lib/open_project/ui/extensible_tabs.rb

@@ -34,7 +34,8 @@ module OpenProject
       class << self
         def tabs
           @tabs ||= {
-            user: core_user_tabs
+            user: core_user_tabs,
+            placeholder_user: core_placeholder_user_tabs
           }
         end
 
@@ -60,32 +61,49 @@ module OpenProject
             {
               name: 'general',
               partial: 'users/general',
-              path: ->(params) { tab_edit_user_path(params[:user], tab: :general) },
+              path: ->(params) { edit_user_path(params[:user], tab: :general) },
               label: :label_general
             },
             {
               name: 'memberships',
-              partial: 'users/memberships',
-              path: ->(params) { tab_edit_user_path(params[:user], tab: :memberships) },
+              partial: 'individual_principals/memberships',
+              path: ->(params) { edit_user_path(params[:user], tab: :memberships) },
               label: :label_project_plural,
               only_if: ->(*) { User.current.admin? }
             },
             {
               name: 'groups',
               partial: 'users/groups',
-              path: ->(params) { tab_edit_user_path(params[:user], tab: :groups) },
+              path: ->(params) { edit_user_path(params[:user], tab: :groups) },
               label: :label_group_plural,
               only_if: ->(*) { User.current.admin? && Group.any? }
             },
             {
               name: 'global_roles',
               partial: 'users/global_roles',
-              path: ->(params) { tab_edit_user_path(params[:user], tab: :global_roles) },
+              path: ->(params) { edit_user_path(params[:user], tab: :global_roles) },
               label: :label_global_roles,
               only_if: ->(*) { User.current.admin? }
             }
           ]
         end
+
+        def core_placeholder_user_tabs
+          [
+            {
+              name: 'general',
+              partial: 'placeholder_users/general',
+              path: ->(params) { edit_placeholder_user_path(params[:placeholder_user], tab: :general) },
+              label: :label_general
+            },
+            {
+              name: 'memberships',
+              partial: 'individual_principals/memberships',
+              path: ->(params) { edit_placeholder_user_path(params[:placeholder_user], tab: :memberships) },
+              label: :label_project_plural
+            }
+          ]
+        end
       end
     end
   end

modules/avatars/lib/open_project/avatars/engine.rb

@@ -51,7 +51,7 @@ module OpenProject::Avatars
     add_tab_entry :user,
                   name: 'avatar',
                   partial: 'avatars/users/avatar_tab',
-                  path: ->(params) { tab_edit_user_path(params[:user], tab: :avatar) },
+                  path: ->(params) { edit_user_path(params[:user], tab: :avatar) },
                   label: :label_avatar,
                   only_if: ->(*) { User.current.admin? && ::OpenProject::Avatars::AvatarManager.avatars_enabled? }
 

modules/costs/lib/costs/engine.rb

@@ -104,7 +104,7 @@ module Costs
     add_tab_entry :user,
                   name: 'rates',
                   partial: 'users/rates',
-                  path: ->(params) { tab_edit_user_path(params[:user], tab: :rates) },
+                  path: ->(params) { edit_user_path(params[:user], tab: :rates) },
                   only_if: ->(*) { User.current.admin? },
                   label: :caption_rate_history
 

modules/two_factor_authentication/config/routes.rb

@@ -19,7 +19,7 @@ OpenProject::Application::routes.draw do
     end
   end
 
-  resources :users do
+  resources :users, only: [] do
     member do
       resources :two_factor_devices,
                 param: :device_id,

modules/two_factor_authentication/lib/open_project/two_factor_authentication/engine.rb

@@ -41,7 +41,7 @@ module OpenProject::TwoFactorAuthentication
     add_tab_entry :user,
                   name: 'two_factor_authentication',
                   partial: 'users/two_factor_authentication',
-                  path: ->(params) { tab_edit_user_path(params[:user], tab: :two_factor_authentication) },
+                  path: ->(params) { edit_user_path(params[:user], tab: :two_factor_authentication) },
                   label: 'two_factor_authentication.label_two_factor_authentication',
                   only_if: ->(*) { User.current.admin? && OpenProject::TwoFactorAuthentication::TokenStrategyManager.enabled? }
 

spec/contracts/attribute_help_texts/base_contract_spec.rb

@@ -27,27 +27,13 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe AttributeHelpTexts::BaseContract do
+  include_context 'ModelContract shared context'
+
   let(:model) { FactoryBot.build_stubbed :work_package_help_text }
   let(:contract) { described_class.new(model, current_user) }
-  subject { contract.validate }
 
-  context 'as admin' do
-    let(:current_user) { FactoryBot.build_stubbed :admin }
-
-    it 'validates the contract' do
-      expect(subject).to eq true
-    end
-  end
-
-  context 'as regular user' do
-    let(:current_user) { FactoryBot.build_stubbed :user }
-
-    it 'returns an error on validation' do
-      expect(subject).to eq false
-      expect(contract.errors.symbols_for(:base))
-        .to match_array [:error_unauthorized]
-    end
-  end
+  it_behaves_like 'contract is valid for active admin users only'
 end

spec/contracts/custom_actions/cu_contract_spec.rb

@@ -29,27 +29,28 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe CustomActions::CuContract do
+  include_context 'ModelContract shared context'
+  
   let(:user) { FactoryBot.build_stubbed(:user) }
   let(:action) do
     FactoryBot.build_stubbed(:custom_action, actions:
                               [CustomActions::Actions::AssignedTo.new])
   end
-  let(:instance) { described_class.new(action) }
+  let(:contract) { described_class.new(action) }
 
   describe 'name' do
     it 'is writable' do
       action.name = 'blubs'
 
-      expect(instance.validate)
-        .to be_truthy
+      expect_contract_valid
     end
     it 'needs to be set' do
       action.name = nil
 
-      expect(instance.validate)
-        .to be_falsey
+      expect_contract_invalid
     end
   end
 
@@ -57,8 +58,7 @@ describe CustomActions::CuContract do
     it 'is writable' do
       action.description = 'blubs'
 
-      expect(instance.validate)
-        .to be_truthy
+      expect_contract_valid
     end
   end
 
@@ -68,26 +68,19 @@ describe CustomActions::CuContract do
 
       action.actions = [responsible_action]
 
-      expect(instance.validate)
-        .to be_truthy
+      expect_contract_valid
     end
 
     it 'needs to have one' do
       action.actions = []
 
-      instance.validate
-
-      expect(instance.errors.symbols_for(:actions))
-        .to eql [:empty]
+      expect_contract_invalid actions: :empty
     end
 
     it 'requires a value if the action requires one' do
       action.actions = [CustomActions::Actions::Status.new([])]
 
-      instance.validate
-
-      expect(instance.errors.symbols_for(:actions))
-        .to eql [:empty]
+      expect_contract_invalid actions: :empty
     end
 
     it 'allows only the allowed values' do
@@ -99,19 +92,13 @@ describe CustomActions::CuContract do
 
       action.actions = [status_action]
 
-      instance.validate
-
-      expect(instance.errors.symbols_for(:actions))
-        .to eql [:inclusion]
+      expect_contract_invalid actions: :inclusion
     end
 
     it 'is not allowed to have an inexistent action' do
       action.actions = [CustomActions::Actions::Inexistent.new]
 
-      instance.validate
-
-      expect(instance.errors.symbols_for(:actions))
-        .to eql [:does_not_exist]
+      expect_contract_invalid actions: :does_not_exist
     end
   end
 
@@ -119,7 +106,7 @@ describe CustomActions::CuContract do
     it 'is writable' do
       action.conditions = [double('some bogus condition', key: 'some', values: 'bogus', validate: true)]
 
-      expect(instance.validate)
+      expect(contract.validate)
         .to be_truthy
     end
 
@@ -132,19 +119,13 @@ describe CustomActions::CuContract do
 
       action.conditions = [status_condition]
 
-      instance.validate
-
-      expect(instance.errors.symbols_for(:conditions))
-        .to eql [:inclusion]
+      expect_contract_invalid conditions: :inclusion
     end
 
     it 'is not allowed to have an inexistent condition' do
       action.conditions = [CustomActions::Conditions::Inexistent.new]
 
-      instance.validate
-
-      expect(instance.errors.symbols_for(:conditions))
-        .to eql [:does_not_exist]
+      expect_contract_invalid conditions: :does_not_exist
     end
   end
 end

spec/contracts/custom_fields/create_contract_spec.rb

@@ -29,28 +29,15 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe CustomFields::CreateContract do
+  include_context 'ModelContract shared context'
+
   let(:cf) { FactoryBot.build :project_custom_field }
   let(:contract) do
     described_class.new(cf, current_user, options: { changed_by_system: [] })
   end
 
-  describe 'as admin' do
-    let(:current_user) { FactoryBot.build_stubbed :admin }
-
-    it 'validates the contract' do
-      expect(contract.validate).to eq(true)
-    end
-  end
-
-  describe 'as regular user' do
-    let(:current_user) { FactoryBot.build_stubbed :user }
-
-    it 'invalidates the contract' do
-      expect(contract.validate).to eq(false)
-      expect(contract.errors.symbols_for(:base))
-        .to match_array [:error_unauthorized]
-    end
-  end
+  it_behaves_like 'contract is valid for active admin users only'
 end

spec/contracts/custom_fields/update_contract_spec.rb

@@ -29,28 +29,15 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe CustomFields::UpdateContract do
+  include_context 'ModelContract shared context'
+
   let(:cf) { FactoryBot.build :project_custom_field }
   let(:contract) do
     described_class.new(cf, current_user, options: { changed_by_system: [] })
   end
 
-  describe 'as admin' do
-    let(:current_user) { FactoryBot.build_stubbed :admin }
-
-    it 'validates the contract' do
-      expect(contract.validate).to eq(true)
-    end
-  end
-
-  describe 'as regular user' do
-    let(:current_user) { FactoryBot.build_stubbed :user }
-
-    it 'invalidates the contract' do
-      expect(contract.validate).to eq(false)
-      expect(contract.errors.symbols_for(:base))
-        .to match_array [:error_unauthorized]
-    end
-  end
+  it_behaves_like 'contract is valid for active admin users only'
 end

spec/contracts/members/create_contract_spec.rb

@@ -28,8 +28,11 @@
 
 require 'spec_helper'
 require_relative './shared_contract_examples'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Members::CreateContract do
+  include_context 'ModelContract shared context'
+
   it_behaves_like 'member contract' do
     let(:member) do
       Member.new(project: member_project,
@@ -37,31 +40,25 @@ describe Members::CreateContract do
                  principal: member_principal)
     end
 
-    subject(:contract) { described_class.new(member, current_user) }
+    let(:contract) { described_class.new(member, current_user) }
 
     describe '#validation' do
       context 'if the principal is nil' do
         let(:member_principal) { nil }
 
-        it 'is invalid' do
-          expect_valid(false, principal: %i(blank))
-        end
+        it_behaves_like 'contract is invalid', principal: :blank
       end
 
       context 'if the principal is a builtin user' do
         let(:member_principal) { FactoryBot.build_stubbed(:anonymous) }
 
-        it 'is invalid' do
-          expect_valid(false, principal: %i(unassignable))
-        end
+        it_behaves_like 'contract is invalid', principal: :unassignable
       end
 
       context 'if the principal is a locked user' do
         let(:member_principal) { FactoryBot.build_stubbed(:locked_user) }
 
-        it 'is invalid' do
-          expect_valid(false, principal: %i(unassignable))
-        end
+        it_behaves_like 'contract is invalid', principal: :unassignable
       end
     end
   end

spec/contracts/members/update_contract_spec.rb

@@ -28,8 +28,12 @@
 
 require 'spec_helper'
 require_relative './shared_contract_examples'
+require 'contracts/shared/model_contract_shared_context'
+
 
 describe Members::UpdateContract do
+  include_context 'ModelContract shared context'
+
   it_behaves_like 'member contract' do
     let(:member) do
       FactoryBot.build_stubbed(:member,
@@ -38,7 +42,7 @@ describe Members::UpdateContract do
                                principal: member_principal)
     end
 
-    subject(:contract) { described_class.new(member, current_user) }
+    let(:contract) { described_class.new(member, current_user) }
 
     describe 'validation' do
       context 'if the principal is changed' do
@@ -46,9 +50,7 @@ describe Members::UpdateContract do
           member.principal = FactoryBot.build_stubbed(:user)
         end
 
-        it 'is invalid' do
-          expect_valid(false, user_id: %i(error_readonly))
-        end
+        it_behaves_like 'contract is invalid', user_id: :error_readonly
       end
 
       context 'if the project is changed' do
@@ -56,17 +58,13 @@ describe Members::UpdateContract do
           member.project = FactoryBot.build_stubbed(:project)
         end
 
-        it 'is invalid' do
-          expect_valid(false, project_id: %i(error_readonly))
-        end
+        it_behaves_like 'contract is invalid', project_id: :error_readonly
       end
 
       context 'if the principal is a locked user' do
         let(:member_principal) { FactoryBot.build_stubbed(:locked_user) }
 
-        it 'is valid' do
-          expect_valid(true)
-        end
+        it_behaves_like 'contract is valid'
       end
     end
   end

spec/contracts/placeholder_users/create_contract_spec.rb

@@ -0,0 +1,42 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
+require_relative 'shared_contract_examples'
+
+describe PlaceholderUsers::CreateContract do
+  include_context 'ModelContract shared context'
+
+  it_behaves_like 'placeholder user contract' do
+    let(:placeholder_user) { PlaceholderUser.new(name: placeholder_user_name) }
+    let(:contract) { described_class.new(placeholder_user, current_user) }
+    let(:current_user) { FactoryBot.build_stubbed(:admin) }
+  end
+end

spec/contracts/placeholder_users/delete_contract_spec.rb

@@ -0,0 +1,41 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
+
+describe PlaceholderUsers::DeleteContract do
+  include_context 'ModelContract shared context'
+
+  let(:placeholder_user) { FactoryBot.build_stubbed(:placeholder_user) }
+  let(:contract) { described_class.new(placeholder_user, current_user) }
+
+  it_behaves_like 'contract is valid for active admin users only'
+end

spec/contracts/placeholder_users/shared_contract_examples.rb

@@ -0,0 +1,73 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+shared_examples_for 'placeholder user contract' do
+  let(:placeholder_user_name) { 'UX Designer' }
+
+  it_behaves_like 'contract is valid for active admin users only'
+
+  context 'name' do
+    context 'is valid' do
+      it_behaves_like 'contract is valid'
+    end
+
+    context 'is not too long' do
+      let(:placeholder_user) { PlaceholderUser.new(name: 'X' * 257) }
+
+      it_behaves_like 'contract is invalid'
+    end
+
+    context 'is not empty' do
+      let(:placeholder_user) { PlaceholderUser.new(name: '') }
+
+      it_behaves_like 'contract is invalid'
+    end
+
+    context 'is unique' do
+      before do
+        PlaceholderUser.create(name: placeholder_user_name)
+      end
+
+      it_behaves_like 'contract is invalid'
+    end
+  end
+
+  describe 'type' do
+    context 'type and class mismatch' do
+      before do
+        placeholder_user.type = User.name
+      end
+
+      it_behaves_like 'contract is invalid'
+    end
+  end
+end

spec/contracts/placeholder_users/update_contract_spec.rb

@@ -0,0 +1,42 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
+require_relative 'shared_contract_examples'
+
+describe PlaceholderUsers::UpdateContract do
+  include_context 'ModelContract shared context'
+
+  it_behaves_like 'placeholder user contract' do
+    let(:placeholder_user) { FactoryBot.build_stubbed(:placeholder_user, name: placeholder_user_name) }
+    let(:contract) { described_class.new(placeholder_user, current_user) }
+    let(:current_user) { FactoryBot.build_stubbed(:admin) }
+  end
+end

spec/contracts/projects/archive_contract_spec.rb

@@ -29,34 +29,13 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Projects::ArchiveContract do
+  include_context 'ModelContract shared context'
+
   let(:project) { FactoryBot.build_stubbed(:project) }
+  let(:contract) { described_class.new(project, current_user) }
 
-  subject(:contract) { described_class.new(project, current_user) }
-
-  def expect_valid(valid, symbols = {})
-    expect(contract.validate).to eq(valid)
-
-    symbols.each do |key, arr|
-      expect(contract.errors.symbols_for(key)).to match_array arr
-    end
-  end
-
-  context 'when user is admin' do
-    let(:current_user) { FactoryBot.build_stubbed :admin }
-
-    it 'is valid' do
-      expect_valid(true)
-    end
-  end
-
-  context 'when user is not admin' do
-    let(:current_user) { FactoryBot.build_stubbed :user }
-    let(:permissions) { [] }
-
-    it 'is invalid' do
-      expect_valid(false, base: %i(error_unauthorized))
-    end
-  end
+  it_behaves_like 'contract is valid for active admin users only'
 end

spec/contracts/projects/delete_contract_spec.rb

@@ -29,37 +29,13 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Projects::DeleteContract do
+  include_context 'ModelContract shared context'
+
   let(:project) { FactoryBot.build_stubbed(:project) }
+  let(:contract) { described_class.new(project, current_user) }
 
-  subject(:contract) { described_class.new(project, current_user) }
-
-  def expect_valid(valid, symbols = {})
-    expect(contract.validate).to eq(valid)
-
-    symbols.each do |key, arr|
-      expect(contract.errors.symbols_for(key)).to match_array arr
-    end
-  end
-
-  shared_examples 'is valid' do
-  end
-
-  context 'when user is admin' do
-    let(:current_user) { FactoryBot.build_stubbed :admin }
-
-    it 'is valid' do
-      expect_valid(true)
-    end
-  end
-
-  context 'when user is not admin' do
-    let(:current_user) { FactoryBot.build_stubbed :user }
-    let(:permissions) { [] }
-
-    it 'is invalid' do
-      expect_valid(false, base: %i(error_unauthorized))
-    end
-  end
+  it_behaves_like 'contract is valid for active admin users only'
 end

spec/contracts/projects/instantiate_template_contract_spec.rb

@@ -28,14 +28,17 @@
 
 require 'spec_helper'
 require_relative './shared_contract_examples'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Projects::InstantiateTemplateContract do
+  include_context 'ModelContract shared context'
+
   let(:user) { FactoryBot.build_stubbed :user }
   let(:project) { Project.new name: 'Foo Bar', identifier: 'foo' }
   let(:template) { FactoryBot.build_stubbed :project }
   let(:options) { { template_project_id: template.id } }
 
-  subject { described_class.new(project, user, options: options) }
+  let(:contract) { described_class.new(project, user, options: options) }
 
   before do
     allow(user)
@@ -52,19 +55,13 @@ describe Projects::InstantiateTemplateContract do
     let(:allowed_to_copy) { true }
     let(:allowed_to_add) { true }
 
-    it 'validates the contract' do
-      expect(subject.validate).to eq true
-      expect(subject.errors).to be_empty
-    end
+    it_behaves_like 'contract is valid'
 
     context 'but may not add projects' do
       let(:allowed_to_copy) { true }
       let(:allowed_to_add) { false }
 
-      it 'fails the parent contract' do
-        expect(subject.validate).to eq false
-        expect(subject.errors[:base]).to include 'may not be accessed.'
-      end
+      it_behaves_like 'contract is invalid', base: :error_unauthorized
     end
   end
 
@@ -72,9 +69,6 @@ describe Projects::InstantiateTemplateContract do
     let(:allowed_to_copy) { false }
     let(:allowed_to_add) { true }
 
-    it 'fails the contract' do
-      expect(subject.validate).to eq false
-      expect(subject.errors[:base]).to include 'may not be accessed.'
-    end
+    it_behaves_like 'contract is invalid', base: :error_unauthorized
   end
 end

spec/contracts/projects/unarchive_contract_spec.rb

@@ -29,34 +29,13 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Projects::UnarchiveContract do
+  include_context 'ModelContract shared context'
+
   let(:project) { FactoryBot.build_stubbed(:project) }
+  let(:contract) { described_class.new(project, current_user) }
 
-  subject(:contract) { described_class.new(project, current_user) }
-
-  def expect_valid(valid, symbols = {})
-    expect(contract.validate).to eq(valid)
-
-    symbols.each do |key, arr|
-      expect(contract.errors.symbols_for(key)).to match_array arr
-    end
-  end
-
-  context 'when user is admin' do
-    let(:current_user) { FactoryBot.build_stubbed :admin }
-
-    it 'is valid' do
-      expect_valid(true)
-    end
-  end
-
-  context 'when user is not admin' do
-    let(:current_user) { FactoryBot.build_stubbed :user }
-    let(:permissions) { [] }
-
-    it 'is invalid' do
-      expect_valid(false, base: %i(error_unauthorized))
-    end
-  end
+  it_behaves_like 'contract is valid for active admin users only'
 end

spec/contracts/queries/update_contract_spec.rb

@@ -29,8 +29,11 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Queries::UpdateContract do
+  include_context 'ModelContract shared context'
+
   let(:project) { FactoryBot.build_stubbed :project }
   let(:query) do
     FactoryBot.build_stubbed(:query, project: project, is_public: public, user: user)
@@ -44,21 +47,13 @@ describe Queries::UpdateContract do
       end
     end
   end
-  subject(:contract) { described_class.new(query, current_user) }
+  let(:contract) { described_class.new(query, current_user) }
 
   before do
     # Assume project is always visible
     allow(contract).to receive(:project_visible?).and_return true
   end
 
-  def expect_valid(valid, symbols = {})
-    expect(contract.validate).to eq(valid)
-
-    symbols.each do |key, arr|
-      expect(contract.errors.symbols_for(key)).to match_array arr
-    end
-  end
-
   describe 'private query' do
     let(:public) { false }
 
@@ -68,17 +63,13 @@ describe Queries::UpdateContract do
       context 'user has no permission to save' do
         let(:permissions) { %i(edit_work_packages) }
 
-        it 'is invalid' do
-          expect_valid(false, base: %i(error_unauthorized))
-        end
+        it_behaves_like 'contract user is unauthorized'
       end
 
       context 'user has permission to save' do
         let(:permissions) { %i(save_queries) }
 
-        it 'is valid' do
-          expect_valid(true)
-        end
+        it_behaves_like 'contract is valid'
       end
     end
 
@@ -86,9 +77,7 @@ describe Queries::UpdateContract do
       let(:user) { FactoryBot.build_stubbed :user }
       let(:permissions) { %i(save_queries) }
 
-      it 'is invalid' do
-        expect_valid(false, base: %i(error_unauthorized))
-      end
+      it_behaves_like 'contract user is unauthorized'
     end
   end
 
@@ -99,25 +88,19 @@ describe Queries::UpdateContract do
     context 'user has no permission to save' do
       let(:permissions) { %i(invalid_permission) }
 
-      it 'is invalid' do
-        expect_valid(false, base: %i(error_unauthorized))
-      end
+      it_behaves_like 'contract user is unauthorized'
     end
 
     context 'user has no permission to manage public' do
       let(:permissions) { %i(manage_public_queries) }
 
-      it 'is valid' do
-        expect_valid(true)
-      end
+      it_behaves_like 'contract is valid'
     end
 
     context 'user has permission to save only own' do
       let(:permissions) { %i(save_queries) }
 
-      it 'is invalid' do
-        expect_valid(false, base: %i(error_unauthorized))
-      end
+      it_behaves_like 'contract user is unauthorized'
     end
   end
 end

spec/contracts/shared/model_contract_shared_context.rb

@@ -0,0 +1,53 @@
+shared_context 'ModelContract shared context' do
+  def expect_contract_valid
+    expect(contract.validate).to eq(true)
+  end
+
+  def expect_contract_invalid(errors = {})
+    expect(contract.validate).to eq(false)
+
+    errors.each do |key, error_symbols|
+      expect(contract.errors.symbols_for(key)).to match_array Array(error_symbols)
+    end
+  end
+
+  shared_examples 'contract is valid' do
+    it do
+      expect_contract_valid
+    end
+  end
+
+  shared_examples 'contract is invalid' do |errors = {}|
+    it do
+      expect_contract_invalid errors
+    end
+  end
+
+  shared_examples 'contract user is unauthorized' do
+    it do
+      expect_contract_invalid base: :error_unauthorized
+    end
+  end
+
+  shared_examples 'contract is valid for active admin users only' do
+    context 'when admin' do
+      let(:current_user) { FactoryBot.build_stubbed(:admin) }
+
+      context 'when admin active' do
+        it_behaves_like 'contract is valid'
+      end
+
+      context 'when admin not active' do
+        let(:current_user) { FactoryBot.build_stubbed(:admin, status: User.statuses[:locked]) }
+
+        it_behaves_like 'contract user is unauthorized'
+      end
+    end
+
+    context 'when not admin' do
+      let(:current_user) { FactoryBot.build_stubbed(:user) }
+
+      it_behaves_like 'contract user is unauthorized'
+    end
+  end
+end

spec/contracts/users/create_contract_spec.rb

@@ -29,30 +29,18 @@
 #++
 
 require 'spec_helper'
+require 'contracts/shared/model_contract_shared_context'
 
 describe Users::CreateContract do
+  include_context 'ModelContract shared context'
+
   let(:user) { FactoryBot.build_stubbed(:user) }
-
-  subject(:contract) { described_class.new(user, current_user) }
-
-  def expect_valid(valid, symbols = {})
-    expect(contract.validate).to eq(valid)
-
-    symbols.each do |key, arr|
-      expect(contract.errors.symbols_for(key)).to match_array arr
-    end
-  end
-
-  shared_examples 'is valid' do
-    it 'is valid' do
-      expect_valid(true)
-    end
-  end
+  let(:contract) { described_class.new(user, current_user) }
 
   context 'when admin' do
     let(:current_user) { FactoryBot.build_stubbed(:admin) }
 
-    it_behaves_like 'is valid'
+    it_behaves_like 'contract is valid'
 
     describe 'requires a password set when active' do
       before do
@@ -60,16 +48,14 @@ describe Users::CreateContract do
         user.activate
       end
 
-      it 'is invalid' do
-        expect_valid(false, password: %i(blank))
-      end
+      it_behaves_like 'contract is invalid', password: :blank
 
       context 'when password is set' do
         before do
           user.password = user.password_confirmation = 'password!password!'
         end
 
-        it_behaves_like 'is valid'
+        it_behaves_like 'contract is valid'
       end
     end
   end
@@ -84,7 +70,7 @@ describe Users::CreateContract do
         user.invite
       end
 
-      it_behaves_like 'is valid'
+      it_behaves_like 'contract is valid'
     end
 
     describe 'cannot set the password' do
@@ -92,9 +78,7 @@ describe Users::CreateContract do
         user.password = user.password_confirmation = 'password!password!'
       end
 
-      it 'is invalid' do
-        expect_valid(false, password: %i(error_readonly))
-      end
+      it_behaves_like 'contract is invalid', password: :error_readonly
     end
 
     describe 'can set the auth_source' do
@@ -105,9 +89,7 @@ describe Users::CreateContract do
         user.auth_source = auth_source
       end
 
-      it 'is valid' do
-        expect_valid(true)
-      end
+      it_behaves_like 'contract is valid'
     end
 
     describe 'cannot set the identity url' do
@@ -115,17 +97,14 @@ describe Users::CreateContract do
         user.identity_url = 'saml:123412foo'
       end
 
-      it 'is invalid' do
-        expect_valid(false, identity_url: %i(error_readonly))
-      end
+      it_behaves_like 'contract is invalid', identity_url: :error_readonly
+
     end
   end
 
   context 'when unauthorized user' do
     let(:current_user) { FactoryBot.build_stubbed(:user) }
 
-    it 'is invalid' do
-      expect_valid(false, base: %i(error_unauthorized))
-    end
+    it_behaves_like 'contract user is unauthorized'
   end
 end

spec/controllers/placeholder_users/memberships_controller_spec.rb

@@ -0,0 +1,66 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+require 'work_package'
+
+describe PlaceholderUsers::MembershipsController, type: :controller do
+  shared_let(:admin) { FactoryBot.create :admin }
+
+  let(:placeholder_user) { FactoryBot.create(:placeholder_user) }
+  let(:anonymous) { FactoryBot.create(:anonymous) }
+
+  describe 'update memberships' do
+    let(:project) { FactoryBot.create(:project) }
+    let(:role) { FactoryBot.create(:role) }
+
+    it 'works' do
+      # i.e. it should successfully add a placeholder user to a project's members
+      as_logged_in_user admin do
+        post :create,
+             params: {
+               placeholder_user_id: placeholder_user.id,
+               membership: {
+                 project_id: project.id,
+                 role_ids: [role.id]
+               }
+             }
+      end
+
+      expect(response).to redirect_to(controller: '/placeholder_users',
+                                      action: 'edit',
+                                      id: placeholder_user.id,
+                                      tab: 'memberships')
+
+      is_member = placeholder_user.reload.memberships.any? { |m|
+        m.project_id == project.id && m.role_ids.include?(role.id)
+      }
+      expect(is_member).to eql(true)
+    end
+  end
+end

spec/controllers/placeholder_users_controller_spec.rb

@@ -0,0 +1,283 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+require 'work_package'
+
+describe PlaceholderUsersController, type: :controller do
+  let(:current_user) { FactoryBot.build(:admin) }
+  let(:placeholder_user) { FactoryBot.create(:placeholder_user) }
+
+  shared_examples 'do not allow non-admins' do
+    let(:current_user) { FactoryBot.build(:user) }
+
+    it 'responds with unauthorized status' do
+      expect(response).to_not be_successful
+      expect(response.status).to eq 403
+    end
+  end
+
+  describe 'GET new' do
+    before do
+      as_logged_in_user(current_user) do
+        get :new
+      end
+    end
+
+    context 'as admin' do
+      it 'renders the new template' do
+        expect(response).to be_successful
+        expect(response).to render_template 'placeholder_users/new'
+        expect(assigns(:placeholder_user)).to be_present
+      end
+    end
+
+    context 'not as admin' do
+      let(:current_user) { FactoryBot.build(:user) }
+
+      it 'responds with unauthorized status' do
+        expect(response).to_not be_successful
+        expect(response.status).to eq 403
+      end
+    end
+  end
+
+  describe 'GET index' do
+    before do
+      as_logged_in_user(current_user) do
+        get :index
+      end
+    end
+
+    context 'as admin' do
+      it 'renders the index template' do
+        expect(response).to be_successful
+        expect(response).to render_template 'placeholder_users/index'
+        expect(assigns(:placeholder_users)).to be_empty
+        expect(assigns(:groups)).not_to be_present
+      end
+    end
+
+    context 'not as admin' do
+      let(:current_user) { FactoryBot.build(:user) }
+
+      it_behaves_like 'do not allow non-admins'
+    end
+  end
+
+  describe 'GET show' do
+    shared_examples 'renders the show template' do
+      it 'renders the show template' do
+        expect(response).to be_successful
+        expect(response).to render_template 'placeholder_users/show'
+        expect(assigns(:placeholder_user)).to be_present
+        expect(assigns(:memberships)).to be_empty
+      end
+    end
+
+    before do
+      as_logged_in_user(current_user) do
+        get :show, params: { id: placeholder_user.id }
+      end
+    end
+
+    context 'as admin' do
+      it_behaves_like 'renders the show template'
+    end
+
+    context 'not as admin' do
+      let(:current_user) { FactoryBot.build(:user) }
+
+      # normal users can also checkout the profile page of placeholder user.
+      it_behaves_like 'renders the show template'
+    end
+  end
+
+  describe 'GET edit' do
+    shared_examples 'renders the edit template' do
+      it 'renders the show template' do
+        expect(response).to be_successful
+        expect(response).to render_template "placeholder_users/edit"
+        expect(assigns(:placeholder_user)).to eql(placeholder_user)
+        expect(assigns(:membership)).to be_present
+        expect(assigns(:individual_principal)).to eql(placeholder_user)
+      end
+    end
+
+    before do
+      as_logged_in_user(current_user) do
+        get :edit, params: { id: placeholder_user.id }
+      end
+    end
+
+    context 'as admin' do
+      it_behaves_like 'renders the edit template'
+    end
+
+    context 'not as admin' do
+      let(:current_user) { FactoryBot.build(:user) }
+
+      # normal users can also checkout the profile page of placeholder user.
+      it_behaves_like 'do not allow non-admins'
+    end
+  end
+
+  describe 'POST create' do
+    let(:params) do
+      {
+        placeholder_user: {
+          name: 'UX Developer'
+        }
+      }
+    end
+
+    before do
+      as_logged_in_user(current_user) do
+        post :create, params: params
+      end
+    end
+
+    context 'as admin' do
+      it 'should be assigned their new values' do
+        user_from_db = PlaceholderUser.last
+        expect(user_from_db.name).to eq('UX Developer')
+      end
+
+      it 'should show a success notice' do
+        expect(flash[:notice]).to eql(I18n.t(:notice_successful_create))
+      end
+
+      it 'should not send an email' do
+        expect(ActionMailer::Base.deliveries.empty?).to be_truthy
+      end
+
+      context 'when user chose to directly create the next placeholder user' do
+        let(:params) do
+          {
+            placeholder_user: {
+                name: 'UX Developer'
+            },
+            continue: true
+          }
+        end
+
+        it 'should redirect to the new page' do
+          expect(response).to redirect_to(new_placeholder_user_url)
+        end
+      end
+
+      context 'when user chose to NOT directly create the next placeholder user' do
+        let(:params) do
+          {
+            placeholder_user: {
+              name: 'UX Developer'
+            }
+          }
+        end
+
+        it 'should redirect to the edit page' do
+          user_from_db = PlaceholderUser.last
+          expect(response).to redirect_to(edit_placeholder_user_url(user_from_db))
+        end
+      end
+    end
+
+    it_behaves_like 'do not allow non-admins'
+
+    context 'invalid params' do
+      let(:params) do
+        {
+          placeholder_user: {
+            name: 'x' * 300 # Name is too long
+          }
+        }
+      end
+
+      it 'should render the edit form with a validation error message' do
+        expect(assigns(:'placeholder_user').errors.messages[:name].first).to include('is too long')
+        expect(response).to render_template 'placeholder_users/new'
+      end
+    end
+  end
+
+  describe 'PUT update' do
+    let(:params) do
+      {
+        id: placeholder_user.id,
+        placeholder_user: {
+          name: 'UX Guru'
+        }
+      }
+    end
+
+    before do
+      as_logged_in_user(current_user) do
+        put :update, params: params
+      end
+    end
+
+    context 'as admin' do
+      it 'should redirect to the edit page' do
+        expect(response).to redirect_to(edit_placeholder_user_url(placeholder_user))
+      end
+
+      it 'should be assigned their new values' do
+        user_from_db = PlaceholderUser.find(placeholder_user.id)
+        expect(user_from_db.name).to eq('UX Guru')
+      end
+
+      it 'should not send an email' do
+        expect(ActionMailer::Base.deliveries.empty?).to be_truthy
+      end
+    end
+
+    it_behaves_like 'do not allow non-admins'
+
+    context 'invalid params' do
+      let(:params) do
+        {
+          id: placeholder_user.id,
+          placeholder_user: {
+            name: 'x' * 300 # Name is too long
+          }
+        }
+      end
+
+      it 'should render the edit form with a validation error message' do
+        expect(assigns(:'placeholder_user').errors.messages[:name].first).to include('is too long')
+        expect(response).to render_template 'placeholder_users/edit'
+      end
+    end
+  end
+
+  describe 'POST destroy' do
+    pending 'Admins can destroy placeholder users'
+    pending 'Non admins cannot destroy placeholder users'
+  end
+end
+

spec/features/placeholder_users/create_spec.rb

@@ -0,0 +1,62 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe 'create placeholder users', type: :feature, selenium: true do
+  let(:current_user) { FactoryBot.create :admin }
+  let(:new_placeholder_user_page) { Pages::NewPlaceholderUser.new }
+
+  before do
+    allow(User).to receive(:current).and_return current_user
+  end
+
+  shared_examples_for 'successful placeholder user creation' do
+    it 'creates the placeholder user' do
+      expect(page).to have_selector('.flash', text: 'Successful creation.')
+
+      new_placeholder_user = PlaceholderUser.order(Arel.sql('id DESC')).first
+
+      expect(current_path).to eql(edit_placeholder_user_path(new_placeholder_user.id))
+    end
+  end
+
+  context 'as admin' do
+    before do
+      visit new_placeholder_user_path
+
+      new_placeholder_user_page.fill_in! name: 'UX Designer'
+
+      perform_enqueued_jobs do
+        new_placeholder_user_page.submit!
+      end
+    end
+
+    it_behaves_like 'successful placeholder user creation'
+  end
+end

spec/features/placeholder_users/edit_placeholder_users_spec.rb

@@ -0,0 +1,58 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe 'edit placeholder users', type: :feature, js: true do
+  let(:current_user) { FactoryBot.create :admin }
+  let(:placeholder_user) { FactoryBot.create :placeholder_user, name: 'UX Developer' }
+
+  before do
+    login_as current_user
+  end
+
+  context 'as admin' do
+    before do
+      visit edit_placeholder_user_path(placeholder_user)
+    end
+
+    it 'can edit name' do
+      expect(page).to have_selector '#placeholder_user_name'
+
+      fill_in 'placeholder_user[name]', with: 'NewName', fill_options: { clear: :backspace }
+
+      click_on 'Save'
+
+      expect(page).to have_selector('.flash.notice', text: 'Successful update.')
+
+      placeholder_user.reload
+
+      expect(placeholder_user.name).to eq 'NewName'
+    end
+  end
+end

spec/features/placeholder_users/index_spec.rb

@@ -0,0 +1,74 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe 'index placeholder users', type: :feature do
+  let!(:current_user) { FactoryBot.create :admin }
+  let!(:anonymous) { FactoryBot.create :anonymous }
+  let!(:placeholder_user_1) do
+    FactoryBot.create(:placeholder_user,
+                      name: 'One',
+                      created_at: 3.minute.ago)
+  end
+  let!(:placeholder_user_2) do
+    FactoryBot.create(:placeholder_user,
+                      name: 'Two',
+                      created_at: 2.minute.ago)
+  end
+  let!(:placeholder_user_3) do
+    FactoryBot.create(:placeholder_user,
+                      name: 'Three',
+                      created_at: 1.minute.ago)
+  end
+  let(:index_page) { Pages::Admin::PlaceholderUsers::Index.new }
+
+  before do
+    login_as(current_user)
+  end
+
+  it 'shows the placeholder users and allows filtering and ordering' do
+    index_page.visit!
+
+    index_page.expect_not_listed(anonymous, current_user)
+
+    # Order is by id, asc
+    # so first ones created are on top.
+    index_page.expect_listed(placeholder_user_1, placeholder_user_2, placeholder_user_3)
+
+    index_page.order_by('Created on')
+    index_page.expect_listed(placeholder_user_3, placeholder_user_2, placeholder_user_1)
+
+    index_page.order_by('Created on')
+    index_page.expect_listed(placeholder_user_1, placeholder_user_2, placeholder_user_3)
+
+    index_page.filter_by_name(placeholder_user_3.name)
+    index_page.expect_listed(placeholder_user_3)
+    index_page.expect_not_listed(placeholder_user_1, placeholder_user_2)
+  end
+end

spec/features/placeholder_users/placeholder_user_memberships_spec.rb

@@ -0,0 +1,77 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+feature 'placeholder user memberships through placeholder user page', type: :feature, js: true do
+  let!(:project) { FactoryBot.create :project, name: 'Project 1', identifier: 'project1' }
+  let!(:project2) { FactoryBot.create :project, name: 'Project 2', identifier: 'project2' }
+  let(:admin) { FactoryBot.create :admin }
+  let(:placeholder_user) { FactoryBot.create :placeholder_user, name: 'UX Designer' }
+
+  let!(:manager)   { FactoryBot.create :role, name: 'Manager' }
+  let!(:developer) { FactoryBot.create :role, name: 'Developer' }
+
+  let(:placeholder_user_page) { Pages::Admin::IndividualPrincipals::Edit.new(placeholder_user) }
+
+  before do
+    login_as(admin)
+
+    placeholder_user_page.visit!
+    placeholder_user_page.open_projects_tab!
+  end
+
+  scenario 'handles role modification flow' do
+    placeholder_user_page.add_to_project! project.name, as: 'Manager'
+
+    member = placeholder_user.memberships.where(project_id: project.id).first
+    placeholder_user_page.edit_roles!(member, %w(Manager Developer))
+
+    # Modify roles
+    placeholder_user_page.expect_project(project.name)
+    placeholder_user_page.expect_roles(project.name, %w(Manager Developer))
+
+    placeholder_user_page.expect_no_membership(project2.name)
+
+    # Remove all roles
+    placeholder_user_page.expect_project(project.name)
+    placeholder_user_page.edit_roles!(member, %w())
+
+    expect(page).to have_selector('.flash.error', text: 'Roles need to be assigned.')
+
+    # Remove the user from the project
+    placeholder_user_page.remove_from_project!(project.name)
+    placeholder_user_page.expect_no_membership(project.name)
+
+    # Re-add the user
+    placeholder_user_page.add_to_project! project.name, as: %w(Manager Developer)
+
+    placeholder_user_page.expect_project(project.name)
+    placeholder_user_page.expect_roles(project.name, %w(Manager Developer))
+  end
+end

spec/features/users/index_spec.rb

@@ -37,9 +37,9 @@ describe 'index users', type: :feature do
   end
 
   describe 'with some sortable users' do
-    let!(:a_user) { FactoryBot.create :user, login: 'a_login', firstname: 'a_first', lastname: 'xxx_a' }
-    let!(:b_user) { FactoryBot.create :user, login: 'b_login', firstname: 'b_first', lastname: 'nnn_b' }
-    let!(:z_user) { FactoryBot.create :user, login: 'z_login', firstname: 'z_first', lastname: 'ccc_z' }
+    let!(:a_user) { FactoryBot.create :user, login: 'aa_login', firstname: 'aa_first', lastname: 'xxx_a' }
+    let!(:b_user) { FactoryBot.create :user, login: 'bb_login', firstname: 'bb_first', lastname: 'nnn_b' }
+    let!(:z_user) { FactoryBot.create :user, login: 'zz_login', firstname: 'zz_first', lastname: 'ccc_z' }
 
     it 'sorts them correctly (Regression #35012)' do
       index_page.visit!

spec/features/users/user_memberships_spec.rb

@@ -36,7 +36,7 @@ feature 'user memberships through user page', type: :feature, js: true do
   let!(:manager)   { FactoryBot.create :role, name: 'Manager' }
   let!(:developer) { FactoryBot.create :role, name: 'Developer' }
 
-  let(:user_page) { Pages::Admin::Users::Edit.new(admin.id) }
+  let(:user_page) { Pages::Admin::IndividualPrincipals::Edit.new(admin) }
 
   before do
     login_as(admin)

spec/helpers/individual_principal_hooks_helper_spec.rb

@@ -0,0 +1,79 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe IndividualPrincipalHooksHelper, type: :helper do
+  let(:user) { FactoryBot.build(:user) }
+  let(:placeholder_user) { FactoryBot.build(:placeholder_user) }
+
+  describe '#individual_principal_key' do
+    it 'returns the class name in underscore format' do
+      expect(helper.individual_principal_key(user)).to eql(:user)
+      expect(helper.individual_principal_key(placeholder_user)).to eql(:placeholder_user)
+    end
+  end
+
+  describe '#call_individual_principals_memberships_hook' do
+    context 'with user and without context' do
+      before do
+        expect(helper).to receive(:call_hook).with(:view_users_memberships_table_foo,
+                                                   user: user)
+      end
+
+      it 'call call_hook with the correct arguments' do
+        helper.call_individual_principals_memberships_hook(user, 'foo')
+      end
+    end
+
+    context 'with placeholder user and without context' do
+      before do
+        expect(helper).to receive(:call_hook).with(:view_placeholder_users_memberships_table_foo,
+                                                   placeholder_user: placeholder_user)
+      end
+
+      it 'call call_hook with the correct arguments' do
+        helper.call_individual_principals_memberships_hook(placeholder_user, 'foo')
+      end
+    end
+
+    context 'with user and with context' do
+      before do
+        expect(helper).to receive(:call_hook).with(:view_users_memberships_table_foo,
+                                                   user: user,
+                                                   yay: 'yo')
+      end
+
+      it 'call call_hook with the correct arguments' do
+        helper.call_individual_principals_memberships_hook(user, 'foo', yay: 'yo')
+      end
+    end
+  end
+end

spec/helpers/tabs_helper_spec.rb

@@ -34,7 +34,7 @@ describe TabsHelper, type: :helper do
   let(:given_tab) do
     { name: 'avatar',
       partial: 'avatars/users/avatar_tab',
-      path: ->(params) { tab_edit_user_path(params[:user], tab: :avatar) },
+      path: ->(params) { edit_user_path(params[:user], tab: :avatar) },
       label: :label_avatar }
   end
 

spec/models/queries/placeholder_users/placeholder_user_query_spec.rb

@@ -0,0 +1,196 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe Queries::PlaceholderUsers::PlaceholderUserQuery, type: :model do
+  let(:instance) { described_class.new }
+  let(:base_scope) { PlaceholderUser.order(id: :desc) }
+
+  context 'without a filter' do
+    describe '#results' do
+      it 'is the same as getting all the users' do
+        expect(instance.results.to_sql).to eql base_scope.to_sql
+      end
+    end
+  end
+
+  context 'with a name filter' do
+    before do
+      instance.where('name', '~', ['a user'])
+    end
+
+    describe '#results' do
+      it 'is the same as handwriting the query' do
+        expected = base_scope
+                     .merge(PlaceholderUser
+                     .where(["LOWER(CONCAT(users.firstname, CONCAT(' ', users.lastname))) LIKE ?",
+                             "%a user%"]))
+
+        expect(instance.results.to_sql).to eql expected.to_sql
+      end
+    end
+
+    describe '#valid?' do
+      it 'is true' do
+        expect(instance).to be_valid
+      end
+
+      it 'is invalid if the filter is invalid' do
+        instance.where('name', '=', [''])
+        expect(instance).to be_invalid
+      end
+    end
+  end
+
+  context 'with a group filter' do
+    let(:group_1) { FactoryBot.build_stubbed(:group) }
+
+    before do
+      allow(Group)
+        .to receive(:exists?)
+        .and_return(true)
+
+      allow(Group)
+        .to receive(:all)
+        .and_return([group_1])
+
+      instance.where('group', '=', [group_1.id])
+    end
+
+    describe '#results' do
+      it 'is the same as handwriting the query' do
+        expected = base_scope
+                       .merge(PlaceholderUser
+                                .where(["users.id IN (#{PlaceholderUser.in_group([group_1.id.to_s]).select(:id).to_sql})"]))
+
+        expect(instance.results.to_sql).to eql expected.to_sql
+      end
+    end
+
+    describe '#valid?' do
+      it 'is true' do
+        expect(instance).to be_valid
+      end
+
+      it 'is invalid if the filter is invalid' do
+        instance.where('group', '=', [''])
+        expect(instance).to be_invalid
+      end
+    end
+  end
+
+  context 'with a non existent filter' do
+    before do
+      instance.where('not_supposed_to_exist', '=', ['bogus'])
+    end
+
+    describe '#results' do
+      it 'returns a query not returning anything' do
+        expected = PlaceholderUser.where(Arel::Nodes::Equality.new(1, 0))
+
+        expect(instance.results.to_sql).to eql expected.to_sql
+      end
+    end
+
+    describe 'valid?' do
+      it 'is false' do
+        expect(instance).to be_invalid
+      end
+
+      it 'returns the error on the filter' do
+        instance.valid?
+
+        expect(instance.errors[:filters]).to eql ["Not supposed to exist does not exist."]
+      end
+    end
+  end
+
+  context 'with an id sortation' do
+    before do
+      instance.order(id: :asc)
+    end
+
+    describe '#results' do
+      it 'is the same as handwriting the query' do
+        expected = PlaceholderUser.merge(PlaceholderUser.order(id: :asc))
+
+        expect(instance.results.to_sql).to eql expected.to_sql
+      end
+    end
+  end
+
+  context 'with a name sortation' do
+    before do
+      instance.order(name: :desc)
+    end
+
+    describe '#results' do
+      it 'is the same as handwriting the query' do
+        expected = "SELECT \"users\".* FROM \"users\" WHERE \"users\".\"type\" = 'PlaceholderUser' ORDER BY \"users\".\"lastname\" DESC, \"users\".\"id\" DESC"
+
+        expect(instance.results.to_sql).to eql expected
+      end
+    end
+  end
+
+  context 'with a group sortation' do
+    before do
+      instance.order(group: :desc)
+    end
+
+    describe '#results' do
+      it 'is the same as handwriting the query' do
+        expected = PlaceholderUser.merge(PlaceholderUser.joins(:groups).order("groups_users.lastname DESC")).order(id: :desc)
+
+        expect(instance.results.to_sql).to eql expected.to_sql
+      end
+    end
+  end
+
+  context 'with a non existing sortation' do
+    # this is a field protected from sortation
+    before do
+      instance.order(password: :desc)
+    end
+
+    describe '#results' do
+      it 'returns a query not returning anything' do
+        expected = PlaceholderUser.where(Arel::Nodes::Equality.new(1, 0))
+
+        expect(instance.results.to_sql).to eql expected.to_sql
+      end
+    end
+
+    describe 'valid?' do
+      it 'is false' do
+        expect(instance).to be_invalid
+      end
+    end
+  end
+end

spec/services/placeholder_users/delete_service_spec.rb

@@ -0,0 +1,100 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe ::PlaceholderUsers::DeleteService, type: :model do
+  skip 'Skipped as we will tackle the DeleteService in a separate PR' do
+    let(:input_user) { FactoryBot.build_stubbed(:user) }
+    let(:project) { FactoryBot.build_stubbed(:project) }
+
+    let(:instance) { described_class.new(input_user, actor) }
+
+    subject { instance.call }
+
+    shared_examples 'deletes the user' do
+      it do
+        expect(input_user).to receive(:lock!)
+        expect(DeleteUserJob).to receive(:perform_later).with(input_user)
+        expect(subject).to eq true
+      end
+    end
+
+    shared_examples 'does not delete the user' do
+      it do
+        expect(input_user).not_to receive(:lock!)
+        expect(DeleteUserJob).not_to receive(:perform_later)
+        expect(subject).to eq false
+      end
+    end
+
+    context 'if deletion by admins allowed', with_settings: { users_deletable_by_admins: true } do
+      context 'with admin user' do
+        let(:actor) { FactoryBot.build_stubbed(:admin) }
+
+        it_behaves_like 'deletes the user'
+      end
+
+      context 'with unprivileged system user' do
+        let(:actor) { User.system }
+
+        before do
+          allow(actor).to receive(:admin?).and_return false
+        end
+
+        it_behaves_like 'does not delete the user'
+      end
+
+      context 'with privileged system user' do
+        let(:actor) { User.system }
+
+        it 'performs deletion' do
+          actor.run_given do
+            expect(input_user).to receive(:lock!)
+            expect(DeleteUserJob).to receive(:perform_later).with(input_user)
+            expect(subject).to eq true
+          end
+        end
+      end
+    end
+
+    context 'if deletion by admins NOT allowed', with_settings: { users_deletable_by_admins: false } do
+      context 'with admin user' do
+        let(:actor) { FactoryBot.build_stubbed(:admin) }
+
+        it_behaves_like 'does not delete the user'
+      end
+
+      context 'with system user' do
+        let(:actor) { User.system }
+
+        it_behaves_like 'does not delete the user'
+      end
+    end
+  end
+end

spec/support/pages/admin/individual_principals/edit.rb

@@ -0,0 +1,119 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'support/pages/page'
+
+module Pages
+  module Admin
+    module IndividualPrincipals
+      class Edit < ::Pages::Page
+        attr_reader :id
+        attr_reader :individual_principal
+
+        def initialize(individual_principal)
+          @individual_principal = individual_principal
+          @id = individual_principal.id
+        end
+
+        def path
+          "/#{individual_principal.class.name.underscore}s/#{id}/edit"
+        end
+
+        def open_projects_tab!
+          within('.content--tabs') do
+            click_on 'Projects'
+          end
+        end
+
+        def add_to_project!(project_name, as:)
+          open_projects_tab!
+          select_project! project_name
+          Array(as).each { |role| check role }
+          click_on 'Add'
+
+          expect_project(project_name)
+        end
+
+        def remove_from_project!(name)
+          open_projects_tab!
+          find_project(name).find('a[data-method=delete]').click
+        end
+
+        def edit_roles!(membership, roles)
+          find("#member-#{membership.id} .memberships--edit-button").click
+
+          page.within("#member-#{membership.id}-roles-form") do
+            page.all('.form--check-box').each do |f|
+              begin
+                f.set false
+              rescue Selenium::WebDriver::Error::InvalidElementStateError
+                # Happens if an element is disabled
+              end
+            end
+            Array(roles).each { |role| page.check role }
+            page.find('.memberships--edit-submit-button').click
+          end
+        end
+
+        def expect_project(project_name)
+          expect(page).to have_selector('tr', text: project_name, wait: 10)
+        end
+
+        def expect_no_membership(project_name)
+          expect(page).to have_no_selector('tr', text: project_name)
+        end
+
+        def expect_roles(project_name, roles)
+          row = page.find('tr', text: project_name, wait: 10)
+
+          roles.each do |role|
+            expect(row).to have_selector('span', text: role)
+          end
+        end
+
+        def find_project(name)
+          find('tr', text: name)
+        end
+
+        def has_project?(name)
+          has_selector? 'tr', text: name
+        end
+
+        def select_project!(project_name)
+          select(project_name, from: 'membership_project_id')
+        end
+
+        def activate!
+          within '.toolbar-items' do
+            click_button 'Activate'
+          end
+        end
+      end
+    end
+  end
+end

spec/support/pages/admin/placeholder_users/index.rb

@@ -0,0 +1,89 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'support/pages/page'
+
+module Pages
+  module Admin
+    module PlaceholderUsers
+      class Index < ::Pages::Page
+        def path
+          "/placeholder_users"
+        end
+
+        def expect_listed(*placeholder_users)
+          rows = page.all 'td.name'
+          expect(rows.map(&:text)).to include(*placeholder_users.map(&:name))
+        end
+
+        def expect_not_listed(*users)
+          rows = page.all 'td.name'
+          expect(rows.map(&:text)).to_not include(*users.map(&:name))
+        end
+
+        def expect_non_listed
+          expect(page)
+            .to have_no_selector('tr.placeholder-user')
+
+          expect(page)
+            .to have_selector('tr.generic-table--empty-row', text: 'There is currently nothing to display.')
+        end
+
+        def filter_by_name(value)
+          fill_in 'Name', with: value
+          click_button 'Apply'
+        end
+
+        def clear_filters
+          click_link 'Clear'
+        end
+
+        def order_by(key)
+          within 'thead' do
+            click_link key
+          end
+        end
+
+        def click_placeholder_user_button(placeholder_user, text)
+          within_user_row(placeholder_user) do
+            click_link text
+          end
+        end
+
+        private
+
+        def within_placeholder_user_row(placeholder_user)
+          row = find('tr.placeholder_user', text: placeholder_user.name)
+          within row do
+            yield
+          end
+        end
+      end
+    end
+  end
+end

spec/support/pages/new_placeholder_user.rb

@@ -0,0 +1,49 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2021 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'support/pages/page'
+
+module Pages
+  class NewPlaceholderUser < Page
+    def path
+      '/placeholder_users/new'
+    end
+
+    ##
+    # Fills in the given user form fields.
+    def fill_in!(fields = {})
+      form = FormFiller.new fields
+
+      form.fill! 'Name', :name
+    end
+
+    def submit!
+      click_button 'Create'
+    end
+  end
+end