checking-test-coverage

name	checking-test-coverage
description	Analyze test coverage gaps and suggest targeted tests for uncovered code paths. Use when evaluating test adequacy, identifying missing edge case tests, or improving confidence before a release.

Checking Test Coverage

Analyze a codebase or changeset to identify gaps in test coverage and recommend targeted tests that maximize confidence.

Analysis Approach

1. Identify What Changed

• Map the files and functions modified in the changeset
• Determine which are business logic vs. configuration vs. infrastructure

2. Trace Code Paths

For each modified function:

• Identify the happy path and verify it has a test
• Identify error/exception paths and check for corresponding tests
• Identify boundary conditions (empty inputs, max values, type coercion) and check coverage
• Identify interactions with external systems (databases, APIs, filesystems) and check for integration tests

3. Evaluate Existing Tests

• Do tests assert behavior (what the code does) rather than implementation (how it does it)?
• Are test names descriptive enough to serve as documentation?
• Do tests cover the specific scenarios introduced by this change?
• Are there tests that need updating due to changed behavior?

4. Recommend New Tests

For each coverage gap, suggest a specific test:

• Name the test clearly: test_<function>_<scenario>_<expected_outcome>
• Describe the setup, action, and assertion
• Prioritize tests that catch regressions over tests that verify obvious behavior

Prioritization

Focus testing effort where it matters most:

1. Critical path — authentication, authorization, payment processing, data persistence
2. Error handling — failure modes that affect users or data integrity
3. Edge cases — boundary values, empty states, concurrent access
4. Integration points — external API calls, database queries, message queues

Output

Produce a summary with:

• Coverage assessment (which paths are tested, which are not)
• Prioritized list of recommended tests with descriptions
• Any existing tests that should be updated or removed