coverage-trend

Coverage Trend Analysis

Usage: /coverage-trend or /coverage-trend --days 30

Purpose: Track test coverage trends over time and identify patterns

Features 🆕:

• Historical coverage tracking
• Trend visualization
• Module-level breakdown
• Coverage delta analysis
• Regression detection

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📊 What This Command Does

Analyzes test coverage evolution over time by:

1. Running current coverage measurement
2. Reading historical coverage data
3. Computing trends and changes
4. Identifying coverage gaps
5. Generating trend visualization

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🚀 Execution Steps

Step 1: Run Current Coverage

Execute coverage measurement:

# Run combined coverage (unit + integration)
make test-coverage-combined

# This generates:
# - htmlcov-combined/index.html (HTML report)
# - coverage.xml (XML report)
# - .coverage (raw data)

Step 2: Extract Coverage Metrics

Parse coverage results:

# Total coverage percentage
CURRENT_COV=$(grep -oP 'Total coverage: \K[0-9.]+' coverage.xml || \
              coverage report --format=total 2>/dev/null || \
              echo "unknown")

# Module-level coverage
coverage report --format=markdown > /tmp/coverage_by_module.md

# Or parse HTML
grep -A 5 "Total" htmlcov-combined/index.html

Step 3: Load Historical Data

Read stored coverage history:

# Coverage history stored in .coverage-history/
# Format: YYYY-MM-DD,coverage_percentage,modules_covered

# Create if doesn't exist
mkdir -p .coverage-history

# Append current measurement
echo "$(date +%Y-%m-%d),$CURRENT_COV" >> .coverage-history/trend.csv

Step 4: Calculate Trends

Analyze coverage evolution:

# Last 7 days average
tail -7 .coverage-history/trend.csv | awk -F',' '{sum+=$2; count++} END {print sum/count}'

# Last 30 days average
tail -30 .coverage-history/trend.csv | awk -F',' '{sum+=$2; count++} END {print sum/count}'

# Trend direction
# Compare last 7 days vs previous 7 days

Step 5: Generate Visualization