feat: add reasoning tests (#856)

tests/reasoning.test.ts

@@ -0,0 +1,64 @@
+import { useAssistant } from '@ai-sdk/react';
+import { ChatPage } from './pages/chat';
+import { test, expect } from '@playwright/test';
+
+test.describe('chat activity with reasoning', () => {
+  let chatPage: ChatPage;
+
+  test.beforeEach(async ({ page }) => {
+    chatPage = new ChatPage(page);
+    await chatPage.createNewChat();
+  });
+
+  test('send user message and generate response with reasoning', async () => {
+    await chatPage.sendUserMessage('why is the sky blue?');
+    await chatPage.waitForMessageGeneration();
+
+    const assistantMessage = await chatPage.getRecentAssistantMessage();
+
+    expect(assistantMessage.content).toBe("it's just blue duh!");
+
+    expect(assistantMessage.reasoning).toBe(
+      'the sky is blue because of rayleigh scattering!',
+    );
+  });
+
+  test('toggle reasoning visibility', async () => {
+    await chatPage.sendUserMessage('why is the sky blue?');
+    await chatPage.waitForMessageGeneration();
+
+    const assistantMessage = await chatPage.getRecentAssistantMessage();
+    const reasoningElement =
+      assistantMessage.element.getByTestId('message-reasoning');
+    expect(reasoningElement).toBeVisible();
+
+    await assistantMessage.toggleReasoningVisibility();
+    await expect(reasoningElement).not.toBeVisible();
+
+    await assistantMessage.toggleReasoningVisibility();
+    await expect(reasoningElement).toBeVisible();
+  });
+
+  test('edit message and resubmit', async () => {
+    await chatPage.sendUserMessage('why is the sky blue?');
+    await chatPage.waitForMessageGeneration();
+
+    const assistantMessage = await chatPage.getRecentAssistantMessage();
+    const reasoningElement =
+      assistantMessage.element.getByTestId('message-reasoning');
+    expect(reasoningElement).toBeVisible();
+
+    const userMessage = await chatPage.getRecentUserMessage();
+
+    await userMessage.edit('why is grass green?');
+    await chatPage.waitForMessageGeneration();
+
+    const updatedAssistantMessage = await chatPage.getRecentAssistantMessage();
+
+    expect(updatedAssistantMessage.content).toBe("it's just green duh!");
+
+    expect(updatedAssistantMessage.reasoning).toBe(
+      'grass is green because of chlorophyll absorption!',
+    );
+  });
+});