✅ test: add e2e regression test for topic switch page reload

Add a regression test to verify that switching topics within the same
agent does not trigger a full browser page reload. The test injects a
window marker before switching and verifies it survives after the switch.

Related: lobehub/lobehub#13309

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

e2e/src/features/regression/topic-switch-no-reload.feature

@@ -0,0 +1,15 @@
+@regression @P0 @agent @topic-switch
+Feature: 切换话题不触发页面全量刷新
+  作为用户，当我在 Agent 执行过程中切换话题时，页面不应该发生全量重新加载
+
+  Background:
+    Given 用户已登录系统
+    And 用户进入 Lobe AI 对话页面
+
+  @AGENT-TOPIC-RELOAD-001 @smoke
+  Scenario: 在同一 Agent 下切换话题不触发页面刷新
+    Given 用户在当前 Agent 中创建了两个对话
+    When 用户在页面注入状态标记
+    And 用户切换到另一个话题
+    Then 页面状态标记应该仍然存在
+    And 页面导航类型不应该是全量加载

e2e/src/steps/agent/topic-switch-no-reload.steps.ts

@@ -0,0 +1,168 @@
+/**
+ * Topic Switch No-Reload Regression Test Steps
+ *
+ * Verifies that switching topics within the same agent does NOT trigger a full
+ * browser page reload. The bug was caused by NavItem's onClick handler skipping
+ * e.preventDefault() when disabled/loading was true, allowing the <a> tag's
+ * default navigation to fire.
+ *
+ * Detection: inject a window marker before switching, verify it survives.
+ */
+import { Given, Then, When } from '@cucumber/cucumber';
+import { expect } from '@playwright/test';
+
+import type { CustomWorld } from '../../support/world';
+import { WAIT_TIMEOUT } from '../../support/world';
+
+// ============================================
+// Helpers
+// ============================================
+
+async function focusAndType(world: CustomWorld, text: string): Promise<void> {
+  const candidates = [
+    world.page.locator(
+      'textarea[placeholder*="Ask"], textarea[placeholder*="Press"], textarea[placeholder*="输入"]',
+    ),
+    world.page.locator('[data-testid="chat-input"] [contenteditable="true"]'),
+    world.page.locator('[data-testid="chat-input"] textarea'),
+  ];
+
+  for (const locator of candidates) {
+    const count = await locator.count();
+    for (let i = 0; i < count; i++) {
+      const item = locator.nth(i);
+      if (await item.isVisible().catch(() => false)) {
+        await item.click({ force: true });
+        await world.page.waitForTimeout(300);
+        await world.page.keyboard.type(text, { delay: 30 });
+        return;
+      }
+    }
+  }
+
+  throw new Error('Could not find a visible chat input');
+}
+
+// ============================================
+// Given Steps
+// ============================================
+
+Given('用户在当前 Agent 中创建了两个对话', async function (this: CustomWorld) {
+  console.log('   📍 Step: 创建第一个对话...');
+
+  // Send first message to create topic 1
+  await focusAndType(this, 'hello');
+  await this.page.keyboard.press('Enter');
+  await this.page.waitForTimeout(3000);
+
+  // Verify a topic appeared in sidebar
+  const topicItems = this.page.locator('[data-testid="topic-item"]');
+  await expect(topicItems.first()).toBeVisible({ timeout: WAIT_TIMEOUT });
+  console.log('   ✅ 第一个对话已创建');
+
+  // Create a new topic
+  console.log('   📍 Step: 创建第二个对话...');
+  const addTopicButton = this.page.locator('svg.lucide-message-square-plus').locator('..');
+  await expect(addTopicButton.first()).toBeVisible({ timeout: 5000 });
+  await addTopicButton.first().click();
+  await this.page.waitForTimeout(1000);
+
+  // Send message to create topic 2
+  await focusAndType(this, 'world');
+  await this.page.keyboard.press('Enter');
+  await this.page.waitForTimeout(3000);
+
+  // Verify we now have at least 2 topics
+  const topicCount = await topicItems.count();
+  console.log(`   📍 话题数量: ${topicCount}`);
+  expect(topicCount).toBeGreaterThanOrEqual(2);
+  console.log('   ✅ 两个对话已创建');
+});
+
+// ============================================
+// When Steps
+// ============================================
+
+When('用户在页面注入状态标记', async function (this: CustomWorld) {
+  console.log('   📍 Step: 注入页面状态标记...');
+
+  await this.page.evaluate(() => {
+    (window as any).__e2eNoReloadMarker = true;
+  });
+
+  // Verify marker was set
+  const marker = await this.page.evaluate(() => (window as any).__e2eNoReloadMarker);
+  expect(marker).toBe(true);
+  console.log('   ✅ 状态标记已注入');
+});
+
+When('用户切换到另一个话题', async function (this: CustomWorld) {
+  console.log('   📍 Step: 切换到另一个话题...');
+
+  const topicItems = this.page.locator('[data-testid="topic-item"]');
+  const topicCount = await topicItems.count();
+  console.log(`   📍 找到 ${topicCount} 个话题`);
+
+  // Find the first non-active topic and click it
+  for (let i = 0; i < topicCount; i++) {
+    const topic = topicItems.nth(i);
+    // Check if this topic is NOT currently active (doesn't have active/filled variant)
+    const isActive = await topic.evaluate((el) => {
+      // Walk up to find the NavItem wrapper and check its variant/active state
+      const navItem = el.closest('[class*="Block"]');
+      return navItem?.getAttribute('data-active') === 'true' || el.classList.contains('active');
+    });
+
+    if (!isActive) {
+      await topic.click();
+      console.log(`   ✅ 已点击第 ${i + 1} 个话题`);
+      await this.page.waitForTimeout(2000);
+      return;
+    }
+  }
+
+  // Fallback: just click the first topic
+  await topicItems.first().click();
+  console.log('   ✅ 已点击第一个话题（fallback）');
+  await this.page.waitForTimeout(2000);
+});
+
+// ============================================
+// Then Steps
+// ============================================
+
+Then('页面状态标记应该仍然存在', async function (this: CustomWorld) {
+  console.log('   📍 Step: 验证页面状态标记...');
+
+  const marker = await this.page.evaluate(() => (window as any).__e2eNoReloadMarker);
+
+  if (marker !== true) {
+    // Take screenshot for debugging
+    await this.takeScreenshot('topic-switch-reload-detected');
+    throw new Error(
+      'Page reload detected! window.__e2eNoReloadMarker was lost after topic switch. ' +
+        'This means the <a> tag default navigation fired instead of SPA routing.',
+    );
+  }
+
+  console.log('   ✅ 页面状态标记仍然存在（未发生 reload）');
+});
+
+Then('页面导航类型不应该是全量加载', async function (this: CustomWorld) {
+  console.log('   📍 Step: 检查导航类型...');
+
+  const navInfo = await this.page.evaluate(() => {
+    const entry = performance.getEntriesByType('navigation')[0] as PerformanceNavigationTiming;
+    return {
+      duration: entry?.duration,
+      type: entry?.type,
+    };
+  });
+
+  console.log(`   📍 Navigation type: ${navInfo.type}, duration: ${navInfo.duration}ms`);
+
+  // If a full page reload happened AFTER the initial load, the navigation type
+  // would still show the initial load type. The window marker check above is
+  // the primary detection. This step provides additional diagnostic info.
+  console.log('   ✅ 导航信息已记录');
+});