Generate Tests

Generate comprehensive tests for the specified code.

Input

The user will provide one of:

• A file path: /test src/utils/validators.ts
• A function name: /test validateEmail
• Just /test — generate tests for recently changed files

Optional flags via $ARGUMENTS:

• --unit — unit tests only (default)
• --integration — integration tests
• --edge — focus on edge cases
• --coverage — aim for high coverage

Process

1. Detect Test Framework

Check the project for:

• vitest.config.* → Vitest
• jest.config.* → Jest
• *.test.ts patterns → Match existing style
• pytest.ini or conftest.py → Pytest
• go.mod → Go testing

If unclear, ask the user.

2. Analyze the Code

Identify:

• Public functions/methods to test
• Input types and valid ranges
• Expected outputs
• Error conditions
• Side effects (mocking needed?)
• Dependencies (what to mock?)

3. Generate Test Cases

For each function, create tests for:

Happy Path

• Normal input → expected output
• Common use cases

Edge Cases

• Empty input ([], "", null, undefined)
• Boundary values (0, -1, MAX_INT)
• Single element collections
• Very large inputs

Error Cases

• Invalid input types
• Out of range values
• Missing required fields
• Network/IO failures (if applicable)

4. Test Structure

Follow AAA pattern:

describe('functionName', () => {
  it('should return X when given Y', () => {
    // Arrange
    const input = { ... };

    // Act
    const result = functionName(input);

    // Assert
    expect(result).toEqual(expected);
  });
});

5. Naming Convention

Test names should be readable as sentences:

• should return empty array when input is empty
• should throw ValidationError when email is invalid
• should call API once per unique user

NOT:

• test1
• works
• validateEmail test

Output

1. Create test file at conventional location:

   • src/foo.ts → src/foo.test.ts or __tests__/foo.test.ts
   • foo.py → test_foo.py or tests/test_foo.py

2. Show summary:

   • Number of test cases generated
   • Coverage estimate
   • Any functions skipped and why

3. Run the tests to verify they pass:

   npm test -- --run <test-file>
   

Guidelines

• Don't test implementation details, test behavior
• One assertion per test when possible
• Mock external dependencies, not internal code
• Tests should be deterministic (no random, no Date.now())
• Fast tests — avoid real network/database calls