---
name: improve-c5-2
description: Improve readiness criterion C5.2 (Unit Test Coverage) in the current project by generating unit tests for untested code. Raises the fulfillment level by one step.
allowed-tools: Bash Read Write Edit
---

# Improve C5.2 — Unit Test Coverage

## Current State

### Test framework detection
!`cat package.json 2>/dev/null | python3 -c "import sys,json; d=json.load(sys.stdin); deps={**d.get('dependencies',{}),**d.get('devDependencies',{})}; tf=[k for k in deps if any(x in k for x in ['jest','mocha','vitest','jasmine','ava'])]; print('Test frameworks:', tf)" 2>/dev/null || true`
!`ls pytest.ini pyproject.toml setup.cfg 2>/dev/null && grep -l "\[tool.pytest\]\|\[pytest\]" pyproject.toml setup.cfg 2>/dev/null || echo "(no pytest config)"`
!`ls *.test.go *_test.go 2>/dev/null | head -5 || echo "(no Go test files at root)"`

### Existing test files
!`find . -maxdepth 5 -type d \( -name "test" -o -name "tests" -o -name "__tests__" -o -name "spec" \) 2>/dev/null | grep -v node_modules | head -10`
!`find . -maxdepth 6 \( -name "*.test.ts" -o -name "*.test.js" -o -name "*_test.py" -o -name "test_*.py" -o -name "*Test.java" \) 2>/dev/null | grep -v node_modules | head -20`

### Coverage configuration
!`cat jest.config.js jest.config.ts 2>/dev/null | grep -i "coverage\|threshold" | head -10 || echo "(no Jest coverage config)"`
!`grep -A5 "\[tool.coverage\|fail_under\|minimum_coverage" pyproject.toml setup.cfg .coveragerc 2>/dev/null | head -15 || echo "(no Python coverage threshold)"`

### Source files to test (sample)
!`find src/ lib/ app/ -maxdepth 3 \( -name "*.ts" -o -name "*.js" -o -name "*.py" \) 2>/dev/null | grep -v "\\.test\.\|__tests__\|\.spec\." | grep -v node_modules | head -20 || echo "(no source files found in src/lib/app/)"`

### Coverage report (if available)
!`ls coverage/ htmlcov/ .coverage 2>/dev/null && echo "(coverage artifacts exist)" || echo "(no coverage run found)"`

## Instructions

**Step 1 — Determine current level:**
- Level 0: No unit test files exist
- Level 1: Test files exist but coverage < 50% (or no coverage measurement)
- Level 2: ≥ 50% coverage configured or evidenced
- Level 3: ≥ 80% coverage configured or evidenced

**Step 2 — Read source files before writing tests:**
Identify the 3–5 most important untested source files (business logic, utilities, services — not configuration or entry points). Read each file fully before writing tests for it.

**Step 3 — Implement the improvement:**

**If current level is 0 → raise to 1:**
1. If no test framework is configured, add one appropriate to the language:
   - Node/TS: add `jest` and `@types/jest` to devDependencies in package.json, add jest config, add `"test": "jest"` script
   - Python: ensure `pytest` is in requirements/pyproject.toml
2. Write unit tests for the 3–5 most important source files identified above. Place them in the appropriate test directory (`tests/`, `__tests__/`, or alongside source with `.test.ts` suffix).
3. Each test file should have at minimum 3–5 test cases covering the main happy path and one edge case per function/method.

**If current level is 1 → raise to 2:**
1. Add a coverage threshold of 50% to the test config:
   - Jest: add `coverageThreshold: { global: { lines: 50 } }` to jest.config
   - pytest: add `[tool.coverage.report] fail_under = 50` to pyproject.toml
2. Identify the untested or under-tested source files from the file list above (files with no corresponding test file).
3. Write additional unit tests for the top 5 untested files, focusing on functions with clear inputs and outputs.

**If current level is 2 → raise to 3:**
1. Raise the coverage threshold to 80%:
   - Jest: update `coverageThreshold` to 80
   - pytest: update `fail_under` to 80
2. Identify gaps: find source files with corresponding test files but with clearly low coverage (look for files with many functions but few test cases).
3. Expand existing tests with additional cases: boundary conditions, error paths, and edge cases for the most critical functions.

**If already at level 3:**
Report that C5.2 is already at its maximum level (3) and no improvement is needed.

**Step 4 — Report:**
State what test files were created or modified, what coverage threshold was set, the before and after level.