validate-coverage-threshold

name	validate-coverage-threshold
description	Validate test coverage meets minimum thresholds for overall, statement, branch, and function coverage

Validate Coverage Threshold

Purpose

Parse test coverage reports and validate that coverage meets minimum thresholds, blocking commits or PRs if coverage is insufficient.

When to Use

• Quality gate validation
• After running tests with coverage
• Pre-commit checks
• Conductor Phase 3 (Quality Assurance)
• As part of quality-gate skill

Default Thresholds

{
  "overall": 80,
  "statements": 80,
  "branches": 75,
  "functions": 80
}

Instructions

Step 1: Check Coverage Data Exists

# Check for coverage file
if [ -f coverage/coverage-summary.json ]; then
  COVERAGE_SOURCE="json"
elif [ -f .claude/baseline/test-output.txt ]; then
  COVERAGE_SOURCE="text"
else
  echo "❌ Error: No coverage data found"
  echo "Run: npm run test -- --coverage"
  exit 1
fi

echo "Coverage source: $COVERAGE_SOURCE"

Step 2: Extract Coverage Metrics

if [ "$COVERAGE_SOURCE" = "json" ]; then
  # Parse from JSON (preferred)
  OVERALL_COV=$(jq -r '.total.lines.pct' coverage/coverage-summary.json)
  STMT_COV=$(jq -r '.total.statements.pct' coverage/coverage-summary.json)
  BRANCH_COV=$(jq -r '.total.branches.pct' coverage/coverage-summary.json)
  FUNC_COV=$(jq -r '.total.functions.pct' coverage/coverage-summary.json)

else
  # Parse from text output (fallback)
  OVERALL_COV=$(grep -oP 'All files.*?\|\s+(\d+\.\d+)' .claude/baseline/test-output.txt | grep -oP '\d+\.\d+' | head -1 || echo "0")
  STMT_COV=$OVERALL_COV
  BRANCH_COV=$OVERALL_COV
  FUNC_COV=$OVERALL_COV
fi

echo "Coverage metrics:"
echo "  Overall: ${OVERALL_COV}%"
echo "  Statements: ${STMT_COV}%"
echo "  Branches: ${BRANCH_COV}%"
echo "  Functions: ${FUNC_COV}%"

Step 3: Load Thresholds

# Use provided thresholds or defaults
MIN_OVERALL=${1:-80}
MIN_STMT=${2:-80}
MIN_BRANCH=${3:-75}
MIN_FUNC=${4:-80}

echo ""
echo "Minimum thresholds:"
echo "  Overall: ${MIN_OVERALL}%"
echo "  Statements: ${MIN_STMT}%"
echo "  Branches: ${MIN_BRANCH}%"
echo "  Functions: ${MIN_FUNC}%"

Step 4: Validate Against Thresholds

echo ""
echo "→ Validating coverage thresholds..."

THRESHOLD_PASSED=true
FAILURES=()

# Check overall
if [ "$(echo "$OVERALL_COV < $MIN_OVERALL" | bc -l)" -eq 1 ]; then
  echo "❌ Overall coverage below threshold: ${OVERALL_COV}% < ${MIN_OVERALL}%"
  THRESHOLD_PASSED=false
  FAILURES+=("overall:${OVERALL_COV}%<${MIN_OVERALL}%")
else
  echo "✅ Overall coverage: ${OVERALL_COV}% ≥ ${MIN_OVERALL}%"
fi

# Check statements
if [ "$(echo "$STMT_COV < $MIN_STMT" | bc -l)" -eq 1 ]; then
  echo "❌ Statement coverage below threshold: ${STMT_COV}% < ${MIN_STMT}%"
  THRESHOLD_PASSED=false
  FAILURES+=("statements:${STMT_COV}%<${MIN_STMT}%")
else
  echo "✅ Statement coverage: ${STMT_COV}% ≥ ${MIN_STMT}%"
fi

# Check branches
if [ "$(echo "$BRANCH_COV < $MIN_BRANCH" | bc -l)" -eq 1 ]; then
  echo "❌ Branch coverage below threshold: ${BRANCH_COV}% < ${MIN_BRANCH}%"
  THRESHOLD_PASSED=false
  FAILURES+=("branches:${BRANCH_COV}%<${MIN_BRANCH}%")
else
  echo "✅ Branch coverage: ${BRANCH_COV}% ≥ ${MIN_BRANCH}%"
fi

# Check functions
if [ "$(echo "$FUNC_COV < $MIN_FUNC" | bc -l)" -eq 1 ]; then
  echo "❌ Function coverage below threshold: ${FUNC_COV}% < ${MIN_FUNC}%"
  THRESHOLD_PASSED=false
  FAILURES+=("functions:${FUNC_COV}%<${MIN_FUNC}%")
else
  echo "✅ Function coverage: ${FUNC_COV}% ≥ ${MIN_FUNC}%"
fi

Step 5: Identify Uncovered Files

if [ "$COVERAGE_SOURCE" = "json" ]; then
  # Find files with low coverage
  UNCOVERED_FILES=$(jq -r '
    to_entries |
    map(select(.key != "total" and .value.lines.pct < 80)) |
    map({file: .key, coverage: .value.lines.pct}) |
    sort_by(.coverage) |
    .[]' coverage/coverage-summary.json | \
    jq -s -c '.')
else
  UNCOVERED_FILES="[]"
fi

Step 6: Return Result

{
  "status": "$([ "$THRESHOLD_PASSED" = true ] && echo 'success' || echo 'warning')",
  "coverage": {
    "overall": $OVERALL_COV,
    "statements": $STMT_COV,
    "branches": $BRANCH_COV,
    "functions": $FUNC_COV
  },
  "thresholds": {
    "overall": $MIN_OVERALL,
    "statements": $MIN_STMT,
    "branches": $MIN_BRANCH,
    "functions": $MIN_FUNC
  },
  "passed": $THRESHOLD_PASSED,
  "failures": $(printf '%s\n' "${FAILURES[@]}" | jq -R -s -c 'split("\n") | map(select(length > 0))'),
  "uncoveredFiles": $UNCOVERED_FILES
}

Output Format

All Thresholds Met

{
  "status": "success",
  "coverage": {
    "overall": 87.5,
    "statements": 88.2,
    "branches": 84.1,
    "functions": 89.3
  },
  "thresholds": {
    "overall": 80,
    "statements": 80,
    "branches": 75,
    "functions": 80
  },
  "passed": true,
  "failures": []
}

Below Threshold

{
  "status": "warning",
  "coverage": {
    "overall": 75.3,
    "statements": 76.1,
    "branches": 72.8,
    "functions": 78.2
  },
  "thresholds": {
    "overall": 80,
    "statements": 80,
    "branches": 75,
    "functions": 80
  },
  "passed": false,
  "failures": [
    "overall:75.3%<80%",
    "statements:76.1%<80%",
    "branches:72.8%<75%",
    "functions:78.2%<80%"
  ],
  "uncoveredFiles": [
    {"file": "src/utils/helpers.ts", "coverage": 45.2},
    {"file": "src/services/api.ts", "coverage": 62.8}
  ]
}

Integration with Quality Gate

Used in quality-gate skill:

### Step 4: Check Test Coverage

Use `validate-coverage-threshold` skill:
- Input: thresholds (or use defaults)
- Expected: All thresholds met

If coverage below threshold:
  ⚠️ WARNING (not blocking for MVP)
  → Log coverage gap
  → Create GitHub issue for improvement
  → Continue with quality gate

If coverage acceptable:
  ✅ Coverage validation passed

Configurable Thresholds

Via Skill Parameters

# Custom thresholds
validate-coverage-threshold 85 85 80 90

# Parameters: overall, statements, branches, functions

Via Config File

// .claude/quality-gate-config.json
{
  "minimumCoverage": 80,
  "coverageThresholds": {
    "overall": 85,
    "statements": 85,
    "branches": 80,
    "functions": 90
  },
  "blockOnCoverage": false
}

Related Skills

• quality-gate - Uses this for coverage validation
• record-quality-baseline - Records coverage baseline
• run-comprehensive-tests - Generates coverage data

Error Handling

No Coverage Data

{
  "status": "error",
  "error": "Coverage data not found",
  "suggestion": "Run tests with coverage: npm run test -- --coverage"
}

Invalid Coverage Format

{
  "status": "error",
  "error": "Cannot parse coverage data",
  "suggestion": "Verify coverage output format"
}

Best Practices

1. Run tests with coverage first - Ensure data exists
2. Set realistic thresholds - Based on project maturity
3. Track coverage trends - Monitor over time
4. Don't block on coverage - Use as warning, not blocker (initially)
5. Identify gaps - Focus on uncovered critical paths

Notes

• Coverage below threshold is WARNING not ERROR (configurable)
• Helps track code coverage quality
• Uncovered files help prioritize test additions
• Can be made blocking in CI/CD pipeline