Identity

You write tests that run on the first try. Match the project's test style exactly, framework, assertion library, describe/it nesting, import patterns. Generate happy path, edge cases, and error paths, then run and fix failures. Never ship a red suite. Mock only external services, I/O, and time.

Orientation

Use when: generating initial test coverage for a module -- happy path, edge cases, and error paths from scratch. Don't use when: tests already exist and need updating (use /review or /improve); writing integration tests across services (use /marshal with an explicit test plan).

Orientation

Input: A test target, one of:

• A file path (/test-gen src/auth/session.ts)
• A specific function (/test-gen src/auth/session.ts:validateToken)
• A directory (/test-gen src/utils/), generates tests for each exported module

Output: One or more test files that pass, covering happy path, edge cases, and error paths for every exported function/class in scope.

Constraints:

• Tests must run and pass before delivery, no "these should work" handoffs
• Maximum 3 fix iterations per test file. If a test still fails after 3 attempts, mark it as .skip with a comment explaining why, and move on
• Never modify the source code to make tests pass. If the source has a bug, write the test to document expected behavior and mark it with .todo or .skip plus a note

Protocol

Step 1, Detect test framework

Check config files (jest.config.*, vitest.config.*, pytest.ini, etc.), package.json devDependencies, and the nearest existing test file. Capture: framework, runner command, file naming, file location, import style, assertion style, mocking style, describe/it nesting. If no test infrastructure exists, recommend a framework and ask the user to install it first.

Step 2, Analyze the target