test(q&a): add comprehensive qa tests and coverage setup (#208)

* test(q&a): add comprehensive qa tests and coverage setup

* test(q&a): align mocks and reset in qa tests

Author: ViktorSvertoka

frontend/.env.example

@@ -97,3 +97,5 @@ TRUST_FORWARDED_HEADERS=0
 
 # emergency switch
 RATE_LIMIT_DISABLED=0
+
+GROQ_API_KEY=

frontend/components/tests/q&a/accordion-list.test.tsx

@@ -0,0 +1,366 @@
+// @vitest-environment jsdom
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+
+const getCachedTermsMock = vi.fn();
+
+vi.mock('@/lib/ai/explainCache', () => ({
+  getCachedTerms: () => getCachedTermsMock(),
+}));
+
+vi.mock('@/components/ui/accordion', () => ({
+  Accordion: ({ children }: { children: React.ReactNode }) => (
+    <div data-testid="accordion">{children}</div>
+  ),
+  AccordionItem: ({ children }: { children: React.ReactNode }) => (
+    <div>{children}</div>
+  ),
+  AccordionTrigger: ({ children }: { children: React.ReactNode }) => (
+    <button type="button">{children}</button>
+  ),
+  AccordionContent: ({ children }: { children: React.ReactNode }) => (
+    <div>{children}</div>
+  ),
+}));
+
+vi.mock('@/components/q&a/CodeBlock', () => ({
+  __esModule: true,
+  default: ({
+    code,
+    content,
+  }: {
+    code?: string;
+    content?: string;
+  }) => <pre data-testid="code-block">{content ?? code}</pre>,
+}));
+
+vi.mock('@/components/q&a/SelectableText', () => ({
+  __esModule: true,
+  default: ({
+    children,
+    onTextSelect,
+    onSelectionClear,
+  }: {
+    children: React.ReactNode;
+    onTextSelect: (text: string, position: { x: number; y: number }) => void;
+    onSelectionClear: () => void;
+  }) => (
+    <div>
+      <button
+        type="button"
+        onClick={() => onTextSelect('CSS', { x: 10, y: 20 })}
+      >
+        select-text
+      </button>
+      <button type="button" onClick={onSelectionClear}>
+        clear-selection
+      </button>
+      {children}
+    </div>
+  ),
+}));
+
+vi.mock('@/components/q&a/FloatingExplainButton', () => ({
+  __esModule: true,
+  default: ({
+    onClick,
+    onDismiss,
+  }: {
+    onClick: () => void;
+    onDismiss: () => void;
+  }) => (
+    <div>
+      <button type="button" onClick={onClick}>
+        explain
+      </button>
+      <button type="button" onClick={onDismiss}>
+        dismiss
+      </button>
+    </div>
+  ),
+}));
+
+vi.mock('@/components/q&a/AIWordHelper', () => ({
+  __esModule: true,
+  default: ({
+    term,
+    isOpen,
+  }: {
+    term: string;
+    isOpen: boolean;
+  }) => (
+    <div data-testid="ai-helper">
+      {isOpen ? `open:${term}` : 'closed'}
+    </div>
+  ),
+}));
+
+vi.mock('@/components/q&a/HighlightCachedTerms', () => ({
+  __esModule: true,
+  default: ({
+    text,
+    cachedTerms,
+    onTermClick,
+  }: {
+    text: string;
+    cachedTerms: Set<string>;
+    onTermClick: (term: string) => void;
+  }) => {
+    const normalized = text.toLowerCase().trim();
+    if (!cachedTerms.has(normalized)) {
+      return <span>{text}</span>;
+    }
+
+    return (
+      <button type="button" onClick={() => onTermClick(text)}>
+        {text}
+      </button>
+    );
+  },
+}));
+
+import AccordionList from '@/components/q&a/AccordionList';
+import type { QuestionEntry } from '@/components/q&a/types';
+
+describe('AccordionList', () => {
+  beforeEach(() => {
+    getCachedTermsMock.mockReturnValue([]);
+  });
+
+  it('renders questions and answer blocks', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is CSS?',
+        category: 'css',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [{ text: 'CSS styles pages.' }],
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    expect(screen.getByText('What is CSS?')).toBeTruthy();
+    expect(screen.getByText('CSS styles pages.')).toBeTruthy();
+  });
+
+  it('opens AI helper from selection', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is CSS?',
+        category: 'css',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [{ text: 'CSS styles pages.' }],
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    fireEvent.click(screen.getByText('select-text'));
+    fireEvent.click(screen.getByText('explain'));
+
+    expect(screen.getByTestId('ai-helper').textContent).toBe('open:CSS');
+  });
+
+  it('opens AI helper when cached term clicked', () => {
+    getCachedTermsMock.mockReturnValue(['HTML']);
+
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is HTML?',
+        category: 'html',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [{ text: 'HTML' }],
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    fireEvent.click(screen.getByText('HTML'));
+
+    expect(screen.getByTestId('ai-helper').textContent).toBe('open:HTML');
+  });
+
+  it('clears selection when requested', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is CSS?',
+        category: 'css',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [{ text: 'CSS styles pages.' }],
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    fireEvent.click(screen.getByText('select-text'));
+    expect(screen.getByText('explain')).toBeTruthy();
+
+    fireEvent.click(screen.getByText('clear-selection'));
+    expect(screen.queryByText('explain')).toBeNull();
+  });
+
+  it('keeps selection when modal is open', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is CSS?',
+        category: 'css',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [{ text: 'CSS styles pages.' }],
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    fireEvent.click(screen.getByText('select-text'));
+    fireEvent.click(screen.getByText('explain'));
+    expect(screen.getByTestId('ai-helper').textContent).toBe('open:CSS');
+
+    fireEvent.click(screen.getByText('clear-selection'));
+    expect(screen.getByTestId('ai-helper').textContent).toBe('open:CSS');
+  });
+
+  it('renders mixed answer blocks', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is HTML?',
+        category: 'html',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [
+              { text: 'Plain' },
+              { text: 'Bold', bold: true },
+              { text: 'Italic', italic: true },
+              { text: 'Both', boldItalic: true },
+              { text: 'Inline', code: true },
+            ],
+          },
+          {
+            type: 'heading',
+            level: 3,
+            children: [{ text: 'Heading' }],
+          },
+          {
+            type: 'bulletList',
+            children: [
+              {
+                type: 'listItem',
+                children: [
+                  { text: 'Item 1' },
+                  { type: 'code', language: 'js', content: 'const a = 1;' },
+                  {
+                    type: 'bulletList',
+                    children: [{ text: 'Nested' }],
+                  },
+                ],
+              },
+              { text: 'Loose item' },
+            ],
+          },
+          {
+            type: 'numberedList',
+            children: [
+              {
+                type: 'listItem',
+                children: [{ text: 'Numbered' }],
+              },
+            ],
+          },
+          {
+            type: 'table',
+            header: [[{ text: 'Col' }]],
+            rows: [[[{ text: 'Cell' }]]],
+          },
+          {
+            type: 'code',
+            language: 'html',
+            content: '<div></div>',
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    expect(screen.getByText('Bold').tagName).toBe('STRONG');
+    expect(screen.getByText('Italic').tagName).toBe('EM');
+    expect(screen.getByText('Both').tagName).toBe('STRONG');
+    expect(screen.getByText('Inline').tagName).toBe('CODE');
+    expect(screen.getByText('Heading').tagName).toBe('SPAN');
+    expect(screen.getByText('Nested')).toBeTruthy();
+    expect(screen.getByText('Col')).toBeTruthy();
+    expect(screen.getByText('Cell')).toBeTruthy();
+    expect(screen.getAllByTestId('code-block').length).toBeGreaterThan(0);
+  });
+
+  it('dismisses explain button', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is CSS?',
+        category: 'css',
+        answerBlocks: [
+          {
+            type: 'paragraph',
+            children: [{ text: 'CSS styles pages.' }],
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    fireEvent.click(screen.getByText('select-text'));
+    expect(screen.getByText('dismiss')).toBeTruthy();
+
+    fireEvent.click(screen.getByText('dismiss'));
+    expect(screen.queryByText('dismiss')).toBeNull();
+  });
+
+  it('renders code blocks in answers', () => {
+    const items: QuestionEntry[] = [
+      {
+        id: 'q1',
+        question: 'What is HTML?',
+        category: 'html',
+        answerBlocks: [
+          {
+            type: 'code',
+            language: 'html',
+            content: '<div></div>',
+          },
+        ],
+      },
+    ];
+
+    render(<AccordionList items={items} />);
+
+    expect(screen.getByTestId('code-block').textContent).toBe('<div></div>');
+  });
+});