Unit tests

Testing Library

1. Jest

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Jest

Used for unit and integration testing of API endpoints and backend functionality.

Modules:

• jest - Testing framework that runs tests in Node.js environment
• ts-jest - Enables seamless TypeScript support in Jest tests
• @jest/globals - Provides Jest globals like describe, test, expect, beforeAll

How It's Used

• API Testing: Tests API endpoints by making HTTP requests and validating responses
• Type Safety: Imports and uses actual TypeScript types from the codebase for response validation
• Parametrized Testing: Uses test.each() to test multiple input combinations with a single test case
• Async Support: Full support for async/await when testing asynchronous operations

Example

import { beforeAll, describe, test, expect } from "@jest/globals";
import type { QuestionAPIResponse } from "@/pages/api/question";

test("ID=1", async () => {
  const json = await get({ id: "1" });
  expect(json.question?.questionId).toEqual(1);
});

// Parametrized tests for multiple scenarios
test.each(queryParamsCombinations)('$qps', async ({ qps }) => {
  const json = await get(qps);
  expect(json.question?.questionId).not.toBeNull();
})

Test Location

• tests/*.spec.ts - unit and integration tests
• tests/*.spec.js - websocket unit and integration tests