Generate Automated Unit Tests

The skill generates comprehensive, maintainable unit tests across languages and frameworks through a six-step process. First it analyzes the codebase with a TestGenerator class that maps languages to their test framework (python: pytest, javascript/typescript: jest, java: junit, go: testing) and uses AST parsing to extract functions, classes, arguments, return types, decorators, docstrings, and cyclomatic complexity. Second, it generates pytest test files from that analysis, emitting a happy-path success test, an empty-input edge case expecting ValueError/TypeError, and an error-handling test expecting an exception for each function, plus a fixture-backed smoke test per class method. Third, it generates Jest tests for JavaScript/TypeScript through a JestTestGenerator that builds describe/it suites covering valid input, graceful null handling, and thrown errors on invalid input. Fourth, it generates React component tests with React Testing Library covering render-without-crashing, correct initial state, user interaction via fireEvent.click, and prop updates verified through rerender. Fifth, a CoverageAnalyzer runs the test command with --coverage --json, parses the coverage report to find uncovered lines and files below an 80% threshold, and generates targeted tests specifically for those gaps. Sixth, it generates mock objects for external dependencies as pytest fixtures using unittest.mock.Mock(spec=...) with a stubbed return value.

Framework-map snippet, quoted verbatim from the source:

        self.framework_map = {
            'python': 'pytest',
            'javascript': 'jest',
            'typescript': 'jest',
            'java': 'junit',
            'go': 'testing'
        }

Output is five deliverables: complete, runnable test files; a coverage report with gaps identified; mock-object fixtures for external dependencies; test documentation explaining the scenarios covered; and CI-integration commands to run the tests in a pipeline.

Use it when unit tests are needed for existing code, when consistent test structure and coverage is wanted, or when mocks, fixtures, and edge-case validation need to be generated. Do not use it when only integration or end-to-end tests are needed, when the source code under test cannot be accessed, or when tests must be hand-written for compliance reasons.

Input is the source file(s) or codebase to test, plus the target language/framework. Output is the generated test suite (pytest, Jest, or React Testing Library depending on language), a coverage-gap report, mock fixtures, test documentation, and CI commands to run everything in a pipeline.

Developers and agents who need to backfill or extend unit test coverage on existing code without hand-writing every happy-path, edge-case, and error-handling test, and who want the coverage gaps identified and specifically targeted rather than guessed at.