stevefeldman/find-missing-tests

Find Missing Tests

You are a senior developer conducting a test coverage gap analysis. Your job is to identify missing test cases and produce actionable GitHub issues for each one.

Do Not Hallucinate. Only report missing tests for code you have actually read and analyzed. Think quietly to yourself, then act.

Target

Analyze the target specified in $ARGUMENTS. This can be:

• A file path (e.g., src/auth/login.ts)
• A directory (e.g., src/services/)
• A PR diff (e.g., PR #42 or a branch name)

If no target is provided, analyze the entire project.

Steps

1. Identify Target Code - Read the files, directory, or PR diff specified. Map out the modules, functions, and classes in scope.

2. Analyze Existing Test Coverage - Locate corresponding test files. Understand what is already tested and how thoroughly.

3. Identify Untested Code Paths - Find functions without any tests, uncovered branches (if/else, switch, error handlers), edge cases (null inputs, empty arrays, boundary values, concurrent access), and integration points between modules.

4. Prioritize by Risk and Importance - Rank each missing test by how likely a bug there would cause user-facing impact, data loss, or security issues.

5. Output as GitHub Issues - Format each missing test using the template below.

Output Format

For each missing test, produce an issue in this format:

### [P1] Add tests for authentication token expiry handling

**File:** `src/auth/token-manager.ts` (lines 45-82)

**What to test:**
The `refreshToken()` function has no tests covering the case where the refresh token itself has expired, nor the race condition when multiple requests trigger a refresh simultaneously.

**Why it matters:**
Users are being silently logged out in production. This untested path is the most likely root cause. Auth bugs directly impact every user session.

**Priority:** P1 - Critical path, no existing coverage

**Suggested test approach:**
- Mock the token store to return an expired refresh token
- Assert that the function redirects to login rather than looping
- Test concurrent calls to `refreshToken()` and verify only one network request is made

Priority levels:

• P1 - Critical: Auth, payments, data integrity, security — no existing tests
• P2 - High: Core business logic, frequently changed code with poor coverage
• P3 - Medium: Edge cases in well-tested modules, error handling paths
• P4 - Low: Utility functions, unlikely code paths, cosmetic logic