test: add tests and questions service tests

Made-with: Cursor

tests/services/question.service.test.ts

@@ -0,0 +1,117 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { QuestionService } from '../../src/services/questions/question.service.js';
+import {
+  createMockDb,
+  selectChainOrdered,
+  selectChainSimple,
+  insertChain,
+  updateChain,
+} from '../test-utils.js';
+
+const mockLlmQuestions = [
+  {
+    questionBankId: 'qb-new',
+    type: 'single_choice' as const,
+    questionText: 'New question?',
+    options: [{ key: 'a', text: 'A' }, { key: 'b', text: 'B' }],
+    correctAnswer: 'a',
+    explanation: 'Explanation',
+    stack: 'js' as const,
+    level: 'beginner' as const,
+  },
+];
+
+describe('QuestionService', () => {
+  let mockDb: ReturnType<typeof createMockDb>;
+  let mockLlmService: { generateQuestions: ReturnType<typeof vi.fn> };
+  let questionService: QuestionService;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockDb = createMockDb();
+    mockLlmService = {
+      generateQuestions: vi.fn().mockResolvedValue({
+        questions: mockLlmQuestions,
+        meta: {
+          llmModel: 'test-model',
+          promptHash: 'hash',
+          generationTimeMs: 100,
+          rawResponse: {},
+        },
+      }),
+    };
+    questionService = new QuestionService(mockDb as never, mockLlmService as never);
+  });
+
+  describe('getQuestionsForTest', () => {
+    it('returns questions from bank when enough approved exist', async () => {
+      const approvedRows = [
+        {
+          id: 'qb-1',
+          type: 'single_choice',
+          questionText: 'Q1?',
+          options: [{ key: 'a', text: 'A' }],
+          correctAnswer: 'a',
+          explanation: 'e',
+        },
+      ];
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChainOrdered(approvedRows))
+        .mockReturnValueOnce(selectChainSimple([]));
+      (mockDb.insert as ReturnType<typeof vi.fn>).mockReturnValueOnce(insertChain([]));
+      (mockDb.update as ReturnType<typeof vi.fn>).mockReturnValueOnce(updateChain([]));
+
+      const result = await questionService.getQuestionsForTest(
+        'user-1',
+        'js',
+        'beginner',
+        1
+      );
+
+      expect(result).toHaveLength(1);
+      expect(result[0].questionBankId).toBe('qb-1');
+      expect(mockLlmService.generateQuestions).not.toHaveBeenCalled();
+    });
+
+    it('calls LLM when not enough questions in bank', async () => {
+      const approvedRows: unknown[] = [];
+      const seenIds: unknown[] = [];
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChainOrdered(approvedRows))
+        .mockReturnValueOnce(selectChainSimple(seenIds));
+      (mockDb.insert as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(insertChain([{ id: 'qb-new', ...mockLlmQuestions[0] }]))
+        .mockReturnValueOnce(insertChain([]))
+        .mockReturnValueOnce(insertChain([]));
+      (mockDb.update as ReturnType<typeof vi.fn>).mockReturnValueOnce(updateChain([]));
+
+      const result = await questionService.getQuestionsForTest(
+        'user-1',
+        'js',
+        'beginner',
+        1
+      );
+
+      expect(result).toHaveLength(1);
+      expect(mockLlmService.generateQuestions).toHaveBeenCalledWith({
+        stack: 'js',
+        level: 'beginner',
+        count: 1,
+      });
+    });
+
+    it('throws when not enough questions available', async () => {
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChainOrdered([]))
+        .mockReturnValueOnce(selectChainSimple([]));
+      mockLlmService.generateQuestions.mockResolvedValueOnce({
+        questions: [],
+        meta: { llmModel: 'x', promptHash: 'y', generationTimeMs: 0, rawResponse: {} },
+      });
+
+      await expect(
+        questionService.getQuestionsForTest('user-1', 'js', 'beginner', 5)
+      ).rejects.toMatchObject({ code: 'QUESTIONS_UNAVAILABLE' });
+    });
+  });
+});

tests/services/tests.service.test.ts

@@ -0,0 +1,230 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { TestsService } from '../../src/services/tests/tests.service.js';
+import {
+  createMockDb,
+  selectChain,
+  selectChainOrdered,
+  selectChainWhere,
+  insertChain,
+  updateChain,
+  updateChainReturning,
+} from '../test-utils.js';
+
+const mockQuestions = [
+  {
+    questionBankId: 'qb-1',
+    type: 'single_choice' as const,
+    questionText: 'What is 2+2?',
+    options: [{ key: 'a', text: '4' }, { key: 'b', text: '3' }],
+    correctAnswer: 'a',
+    explanation: 'Basic math',
+  },
+];
+
+describe('TestsService', () => {
+  let mockDb: ReturnType<typeof createMockDb>;
+  let mockQuestionService: { getQuestionsForTest: ReturnType<typeof vi.fn> };
+  let testsService: TestsService;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockDb = createMockDb();
+    mockQuestionService = {
+      getQuestionsForTest: vi.fn().mockResolvedValue(mockQuestions),
+    };
+    testsService = new TestsService(mockDb as never, mockQuestionService as never);
+  });
+
+  describe('createTest', () => {
+    it('creates a test with questions from QuestionService', async () => {
+      const mockTest = {
+        id: 'test-1',
+        userId: 'user-1',
+        stack: 'js',
+        level: 'beginner',
+        questionCount: 1,
+        mode: 'fixed',
+        status: 'in_progress',
+        score: null,
+        startedAt: new Date(),
+        finishedAt: null,
+        timeLimitSeconds: null,
+      };
+      const mockTqRows = [
+        {
+          id: 'tq-1',
+          testId: 'test-1',
+          questionBankId: 'qb-1',
+          orderNumber: 1,
+          type: 'single_choice',
+          questionText: 'What is 2+2?',
+          options: [{ key: 'a', text: '4' }],
+          correctAnswer: 'a',
+          explanation: 'Basic math',
+          userAnswer: null,
+          isCorrect: null,
+          answeredAt: null,
+        },
+      ];
+      (mockDb.insert as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(insertChain([mockTest]))
+        .mockReturnValueOnce(insertChain([]));
+      (mockDb.select as ReturnType<typeof vi.fn>).mockReturnValueOnce(
+        selectChainOrdered(mockTqRows)
+      );
+
+      const result = await testsService.createTest('user-1', {
+        stack: 'js',
+        level: 'beginner',
+        questionCount: 1,
+      });
+
+      expect(result.id).toBe('test-1');
+      expect(result.questions).toHaveLength(1);
+      expect(mockQuestionService.getQuestionsForTest).toHaveBeenCalledWith(
+        'user-1',
+        'js',
+        'beginner',
+        1
+      );
+    });
+
+    it('throws when questionCount is out of range', async () => {
+      await expect(
+        testsService.createTest('user-1', {
+          stack: 'js',
+          level: 'beginner',
+          questionCount: 0,
+        })
+      ).rejects.toMatchObject({ code: 'BAD_REQUEST' });
+
+      await expect(
+        testsService.createTest('user-1', {
+          stack: 'js',
+          level: 'beginner',
+          questionCount: 51,
+        })
+      ).rejects.toMatchObject({ code: 'BAD_REQUEST' });
+    });
+  });
+
+  describe('answerQuestion', () => {
+    it('returns updated question snapshot when answer is correct', async () => {
+      const mockTest = { id: 't-1', userId: 'user-1', status: 'in_progress' };
+      const mockTq = {
+        id: 'tq-1',
+        testId: 't-1',
+        correctAnswer: 'a',
+        userAnswer: null,
+        questionBankId: 'qb-1',
+        orderNumber: 1,
+        type: 'single_choice',
+        questionText: 'Q?',
+        options: [{ key: 'a', text: 'A' }],
+        explanation: 'exp',
+      };
+      const updatedTq = { ...mockTq, userAnswer: 'a', isCorrect: true, answeredAt: new Date() };
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChain([mockTest]))
+        .mockReturnValueOnce(selectChain([mockTq]));
+      (mockDb.update as ReturnType<typeof vi.fn>).mockReturnValueOnce(
+        updateChainReturning([updatedTq])
+      );
+
+      const result = await testsService.answerQuestion('user-1', 't-1', 'tq-1', 'a');
+
+      expect(result.isCorrect).toBe(true);
+      expect(result.userAnswer).toBe('a');
+    });
+
+    it('throws when test not found', async () => {
+      (mockDb.select as ReturnType<typeof vi.fn>).mockReturnValueOnce(selectChain([]));
+
+      await expect(
+        testsService.answerQuestion('user-1', 'bad-id', 'tq-1', 'a')
+      ).rejects.toMatchObject({ code: 'NOT_FOUND' });
+    });
+
+    it('throws when test is already finished', async () => {
+      (mockDb.select as ReturnType<typeof vi.fn>).mockReturnValueOnce(
+        selectChain([{ id: 't-1', userId: 'user-1', status: 'completed' }])
+      );
+
+      await expect(
+        testsService.answerQuestion('user-1', 't-1', 'tq-1', 'a')
+      ).rejects.toMatchObject({ code: 'TEST_ALREADY_FINISHED' });
+    });
+  });
+
+  describe('finishTest', () => {
+    it('throws when there are unanswered questions', async () => {
+      const mockTest = { id: 't-1', userId: 'user-1', status: 'in_progress', stack: 'js', level: 'beginner' };
+      const mockQuestionsWithUnanswered = [
+        { id: 'tq-1', testId: 't-1', userAnswer: 'a', isCorrect: true },
+        { id: 'tq-2', testId: 't-1', userAnswer: null, isCorrect: null },
+      ];
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChain([mockTest]))
+        .mockReturnValueOnce(selectChainWhere(mockQuestionsWithUnanswered));
+
+      await expect(
+        testsService.finishTest('user-1', 't-1')
+      ).rejects.toMatchObject({ code: 'NO_ANSWERS' });
+    });
+  });
+
+  describe('getById', () => {
+    it('returns null when test not found', async () => {
+      (mockDb.select as ReturnType<typeof vi.fn>).mockReturnValueOnce(selectChain([]));
+
+      const result = await testsService.getById('user-1', 'bad-id');
+
+      expect(result).toBeNull();
+    });
+
+    it('returns test with questions when found', async () => {
+      const mockTest = {
+        id: 't-1',
+        userId: 'user-1',
+        stack: 'js',
+        level: 'beginner',
+        questionCount: 2,
+        mode: 'fixed',
+        status: 'in_progress',
+        score: null,
+        startedAt: new Date(),
+        finishedAt: null,
+        timeLimitSeconds: null,
+      };
+      const mockTqRows = [
+        { id: 'tq-1', testId: 't-1', orderNumber: 1, questionBankId: 'qb-1', type: 'single_choice', questionText: 'Q1', options: [], correctAnswer: 'a', explanation: 'e', userAnswer: null, isCorrect: null, answeredAt: null },
+      ];
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChain([mockTest]))
+        .mockReturnValueOnce(selectChainOrdered(mockTqRows));
+
+      const result = await testsService.getById('user-1', 't-1');
+
+      expect(result).not.toBeNull();
+      expect(result!.id).toBe('t-1');
+      expect(result!.questions).toHaveLength(1);
+    });
+  });
+
+  describe('getHistory', () => {
+    it('returns paginated test history', async () => {
+      const mockTests = [
+        { id: 't-1', userId: 'user-1', stack: 'js', level: 'beginner', questionCount: 1, mode: 'fixed', status: 'completed', score: 100, startedAt: new Date(), finishedAt: new Date(), timeLimitSeconds: null },
+      ];
+      const mockTqRows = [];
+      (mockDb.select as ReturnType<typeof vi.fn>)
+        .mockReturnValueOnce(selectChainOrdered(mockTests))
+        .mockReturnValueOnce(selectChainOrdered(mockTqRows));
+
+      const result = await testsService.getHistory('user-1', { limit: 10, offset: 0 });
+
+      expect(result.tests).toHaveLength(1);
+      expect(result.total).toBe(1);
+    });
+  });
+});

tests/test-utils.ts

@@ -24,6 +24,40 @@ export function selectChain(resolveAtLimit: unknown[] = []) {
   };
 }
 
+/** Build a select chain for .from().where().orderBy() - orderBy is terminal */
+export function selectChainOrdered(resolveAtOrderBy: unknown[] = []) {
+  const orderByThenable = {
+    then: (resolve: (v: unknown) => void) => resolve(resolveAtOrderBy),
+  };
+  return {
+    from: vi.fn().mockReturnValue({
+      where: vi.fn().mockReturnValue({
+        orderBy: vi.fn().mockReturnValue(orderByThenable),
+      }),
+    }),
+  };
+}
+
+/** Build a select chain for .from().where() with no orderBy - used by select({...}).from() */
+export function selectChainSimple(resolveRows: unknown[] = []) {
+  const thenable = { then: (resolve: (v: unknown) => void) => resolve(resolveRows) };
+  return {
+    from: vi.fn().mockReturnValue({
+      where: vi.fn().mockReturnValue(thenable),
+    }),
+  };
+}
+
+/** Build a select chain for .from().where() - where is terminal (no orderBy/limit) */
+export function selectChainWhere(resolveAtWhere: unknown[] = []) {
+  const thenable = { then: (resolve: (v: unknown) => void) => resolve(resolveAtWhere) };
+  return {
+    from: vi.fn().mockReturnValue({
+      where: vi.fn().mockReturnValue(thenable),
+    }),
+  };
+}
+
 /** Build an insert chain that resolves at .returning() or .values() */
 export function insertChain(resolveAtReturning: unknown[] = []) {
   const returningFn = vi.fn().mockResolvedValue(resolveAtReturning);
@@ -46,6 +80,18 @@ export function updateChain(resolveAtWhere: unknown[] = []) {
   };
 }
 
+/** Build an update chain with .where().returning() */
+export function updateChainReturning(resolveAtReturning: unknown[] = []) {
+  const returningFn = vi.fn().mockResolvedValue(resolveAtReturning);
+  return {
+    set: vi.fn().mockReturnValue({
+      where: vi.fn().mockReturnValue({
+        returning: returningFn,
+      }),
+    }),
+  };
+}
+
 /** Build a delete chain that resolves at .where() */
 export function deleteChain() {
   return {