ReddRadar
Agent skill
exunit-code-review
Reviews ExUnit test code for proper patterns, boundary mocking with Mox, and test adapter usage. Use when reviewing _test.exs files or test helper configurations.
Install this agent skill to your Project
npx add-skill https://github.com/existential-birds/beagle/tree/main/plugins/beagle-elixir/skills/exunit-code-review
SKILL.md
ExUnit Code Review
Quick Reference
| Issue Type | Reference |
|---|---|
| Async tests, setup, describe, tags | references/exunit-patterns.md |
| Behavior-based mocking, expectations | references/mox-boundaries.md |
| Bypass, Swoosh, Oban testing | references/test-adapters.md |
| What to mock vs real, Ecto sandbox | references/integration-tests.md |
Mock Boundary Philosophy
Mock at external boundaries:
- HTTP clients, external APIs, third-party services
- Slow resources: file system, email, job queues
- Non-deterministic: DateTime.utc_now(), :rand
DO NOT mock internal code:
- Contexts, schemas, GenServers
- Internal modules, PubSub
- Anything you wrote
Review Checklist
Test Structure
- Tests are
async: trueunless sharing database state - Describe-blocks group related tests
- Setup extracts common test data
- Tests have clear arrange/act/assert structure
Mocking
- Mox used for external boundaries (HTTP, APIs)
- Behaviors defined for mockable interfaces
- No mocking of internal modules
- verify_on_exit! in setup for strict mocking
Test Adapters
- Bypass for HTTP endpoint mocking
- Swoosh.TestAdapter for email testing
- Oban.Testing for background job assertions
Database
- Ecto.Adapters.SQL.Sandbox for isolation
- Async tests don't share database state
- Fixtures/factories used consistently
Valid Patterns (Do NOT Flag)
- Mock in unit test, real in integration - Different test levels have different needs
- Not mocking database in integration tests - Database is internal
- Simple inline test data - Not everything needs factories
- Testing private functions via public API - Correct approach
Context-Sensitive Rules
| Issue | Flag ONLY IF |
|---|---|
| Not async | Test actually needs shared state |
| Missing mock | External call exists AND no mock/bypass |
| Mock internal | Module being mocked is internal code |
Before Submitting Findings
Use the issue format: [FILE:LINE] ISSUE_TITLE for each finding.
Load and follow review-verification-protocol before reporting any issue.
Recommended Agent Skills
Expand your agent's capabilities with these related and highly-rated skills.
existential-birds/beagle
review-python
Comprehensive Python/FastAPI backend code review with optional parallel agents
existential-birds/beagle
review-verification-protocol
Mandatory verification steps for all code reviews to reduce false positives. Load this skill before reporting ANY code review findings.
existential-birds/beagle
sqlalchemy-code-review
Reviews SQLAlchemy code for session management, relationships, N+1 queries, and migration patterns. Use when reviewing SQLAlchemy 2.0 code, checking session lifecycle, relationship() usage, or Alembic migrations.
existential-birds/beagle
fastapi-code-review
Reviews FastAPI code for routing patterns, dependency injection, validation, and async handlers. Use when reviewing FastAPI apps, checking APIRouter setup, Depends() usage, or response models.
existential-birds/beagle
pytest-code-review
Reviews pytest test code for async patterns, fixtures, parametrize, and mocking. Use when reviewing test_*.py files, checking async test functions, fixture usage, or mock patterns.
existential-birds/beagle
postgres-code-review
Reviews PostgreSQL code for indexing strategies, JSONB operations, connection pooling, and transaction safety. Use when reviewing SQL queries, database schemas, JSONB usage, or connection management.
Didn't find tool you were looking for?