Test Generator

Test Generator

Generate thorough test suites by analyzing source code and producing tests that cover happy paths, edge cases, and error scenarios.

Workflow

1. Detect the testing framework Look for configuration files and existing tests:

   • jest.config.* or vitest.config.* → Jest/Vitest
   • pytest.ini or conftest.py → Pytest
   • *_test.go files → Go testing
   • *.test.ts, *.spec.ts → TypeScript testing

   Also check package.json for test scripts and dependencies.

2. Read the source code Read the file(s) the user wants tested. Understand:

   • Function signatures and return types
   • Dependencies and imports
   • Side effects (API calls, DB queries, file I/O)
   • Edge cases (null inputs, empty arrays, boundary values)

3. Read existing tests (if any) Check for existing test files to match style and avoid duplication.

4. Generate tests covering:

   • Happy path: Normal expected behavior with typical inputs
   • Edge cases: Empty inputs, null/undefined, boundary values, large inputs
   • Error handling: Invalid inputs, thrown exceptions, rejected promises
   • Integration points: Mock external dependencies appropriately

5. Write the test file Follow the project's naming convention (e.g., foo.test.ts or test_foo.py).

Rules

• Match the existing test style in the project
• Use descriptive test names: it("should return empty array when input is null")
• Group related tests with describe blocks
• Mock external dependencies (APIs, databases) — never call real services
• Include setup/teardown when needed
• Aim for 80%+ code coverage of the target file
• Add comments explaining WHY a test exists for non-obvious cases
• Always run the tests after generating to verify they pass