test

name	test
description	Use after writing or modifying code to run targeted tests and identify coverage gaps, before claiming code works
tags	["quality"]

Smart Test Runner

Analyze recent changes, run targeted tests, identify coverage gaps, and optionally write missing tests.

Arguments

• $ARGUMENTS - Optional: --full for full test suite, --write to auto-write missing tests, or a specific file/directory to test

Context

• Project type: !find . -maxdepth 1 \( -name go.mod -o -name Gemfile -o -name package.json -o -name Cargo.toml -o -name pyproject.toml -o -name setup.py -o -name requirements.txt -o -name pom.xml -o -name build.gradle -o -name Makefile \) 2>/dev/null | head -5
• Changed files: !git diff --name-only HEAD~1 2>/dev/null | head -50
• Test files: !find . -maxdepth 4 \( -name "*_test.*" -o -name "*.test.*" -o -name "*_spec.*" -o -name "test_*" \) 2>/dev/null | head -20
• Git status: !git status --short 2>/dev/null || echo '(not in a git repo)'

Instructions

Step 1: Detect Test Framework

From the project type context above, determine:

Indicator	Framework	Run Command
go.mod	Go test	go test ./...
Gemfile	RSpec or Minitest	bundle exec rspec or bundle exec rake test
package.json	Jest, Vitest, or Mocha	npm test or npx jest or npx vitest
pyproject.toml / requirements.txt	pytest or unittest	pytest or python -m pytest
Cargo.toml	cargo test	cargo test
pom.xml / build.gradle	JUnit	mvn test or gradle test

If you can't detect a test framework, tell the user and ask how to run tests.

Step 2: Determine Test Scope

IF $ARGUMENTS contains "--full":
  Run the full test suite

ELSE IF $ARGUMENTS contains a specific file or directory:
  Run tests for that target only

ELSE:
  Analyze changed files and map them to test files:
  1. For each changed file, look for corresponding test file:
     - Go: foo.go → foo_test.go
     - Ruby: app/models/user.rb → spec/models/user_spec.rb
     - JS/TS: src/utils.ts → src/utils.test.ts or __tests__/utils.test.ts
     - Python: module.py → test_module.py or tests/test_module.py
     - Rust: src/lib.rs → tests in same file or tests/ directory
  2. Run only the mapped test files
  3. If no test files map to the changes, run the full suite

Step 3: Run Tests

Run the determined tests. Capture output including:

• Pass/fail status for each test
• Failure messages with file and line numbers
• Total counts: passed, failed, skipped

If tests fail, read the failing test files and the source files they test to understand the failures.

Step 4: Measure and Analyze Coverage

First, try to use the project's coverage tool if available:

Framework	Coverage Command
Go	go test -coverprofile=coverage.out ./... && go tool cover -func=coverage.out
pytest	pytest --cov --cov-report=term-missing
Jest	npx jest --coverage
RSpec	Coverage via simplecov (runs automatically if in Gemfile)
cargo	cargo tarpaulin (if installed)

If a coverage tool ran, report the coverage percentage and uncovered lines.

If no coverage tool is available, fall back to manual analysis. Read each changed file and its corresponding test file (if any). Identify:

1. Untested functions/methods -- changed code with no corresponding test
2. Missing edge cases -- tests exist but don't cover error paths, boundary values, or nil/empty inputs
3. New code without tests -- newly created files with no test file

Report each gap with: file, function/method, what's missing.

Step 5: Write Tests (if requested)

IF $ARGUMENTS contains "--write" OR user confirms:
  For each coverage gap identified:
  1. Write a test following existing test patterns in the project
  2. Use the same test framework, naming conventions, and style
  3. Run the new test to verify it passes
  4. Report what was written

Step 6: Report

## Test Results

### Run Summary
- **Framework:** {detected framework}
- **Scope:** {targeted / full suite}
- **Status:** PASS / FAIL
- **Passed:** {N} | **Failed:** {N} | **Skipped:** {N}

### Failures (if any)
| Test | File | Error |
|------|------|-------|
| {test name} | {file:line} | {brief error} |

### Coverage Gaps
| Source File | Function/Method | Gap |
|-------------|-----------------|-----|
| {file} | {function} | {what's missing} |

### New Tests Written (if --write)
| Test File | Tests Added | Covers |
|-----------|-------------|--------|
| {file} | {N} | {what it tests} |

### Recommendation
{1-2 sentences: overall health and what to do next}