qe-coverage-analysis

# QE Coverage Analysis ## Purpose Guide the use of v3's advanced coverage analysis capabilities including sublinear gap detection algorithms, risk-weighted coverage scoring, and intelligent test prioritization based on code criticality. ## Activation - When analyzing test coverage - When identifying coverage gaps - When prioritizing testing effort - When setting coverage targets - When assessing code risk ## Quick Start ```bash # Analyze coverage with gap detection aqe coverage analyze --source src/ --tests tests/ # Find high-risk uncovered code aqe coverage gaps --risk-weighted --threshold 80 # Generate coverage report aqe coverage report --format html --output coverage-report/ # Compare coverage between branches aqe coverage diff --base main --head feature-branch ``` ## Agent Workflow ```typescript // Comprehensive coverage analysis Task("Analyze coverage gaps", ` Perform O(log n) coverage analysis on src/: - Calculate statement, branch, function coverage - Identify uncovered critical paths - Risk-weight gaps by code complexity and change frequency - Recommend tests to write for maximum coverage impact `, "qe-coverage-specialist") // Risk-based prioritization Task("Prioritize coverage effort", ` Analyze coverage gaps and prioritize by: - Business criticality (payment, auth, data) - Code complexity (cyclomatic > 10) - Recent bug history - Change frequency Output prioritized list of files needing tests. `, "qe-coverage-analyzer") ``` ## Analysis Strategies ### 1. Sublinear Gap Detection ```typescript await coverageAnalyzer.detectGaps({ algorithm: 'sublinear', // O(log n) complexity source: 'src/**/*.ts', metrics: ['statement', 'branch', 'function'], sampling: { enabled: true, confidence: 0.95, maxSamples: 1000 } }); ``` ### 2. Risk-Weighted Coverage ```typescript await coverageAnalyzer.riskWeightedAnalysis({ coverage: coverageReport, riskFactors: { complexity: { weight: 0.3, threshold: 10 }, changeFrequency: { weight: 0.25, window: '90d' }, bugHistory: { weight: 0.25, window: '180d' }, criticality: { weight: 0.2, tags: ['payment', 'auth'] } }, output: { riskScore: true, prioritizedGaps: true } }); ``` ### 3. Differential Coverage ```typescript await coverageAnalyzer.diffCoverage({ base: 'main', head: 'feature-branch', requirements: { newCode: 80, // New code must have 80% coverage modifiedCode: 'maintain', // Don't decrease existing deletedCode: 'ignore' } }); ``` ## Coverage Thresholds ```yaml thresholds: global: statements: 80 branches: 75 functions: 85 lines: 80 per_file: min_statements: 70 critical_paths: 90 new_code: statements: 85 branches: 80 exceptions: - path: "src/migrations/**" reason: "Database migrations" - path: "src/generated/**" reason: "Auto-generated code" ``` ## Coverage Report ```typescript interface CoverageAnalysis { summary: { statements: { covered: number; total: number; percentage: number }; branches: { covered: number; total: number; percentage: number }; functions: { covered: number; total: number; percentage: number }; }; gaps: { file: string; uncoveredLines: number[]; uncoveredBranches: BranchInfo[]; riskScore: number; suggestedTests: string[]; }[]; trends: { period: string; coverageChange: number; newGaps: number; closedGaps: number; }; recommendations: { priority: 'critical' | 'high' | 'medium' | 'low'; file: string; action: string; expectedImpact: number; }[]; } ``` ## Quality Gates ```yaml quality_gates: coverage: block_merge: - new_code_coverage < 80 - coverage_regression > 5 - critical_path_uncovered warn: - overall_coverage < 75 - branch_coverage < 70 metrics: - track_trends: true - alert_on_decline: 3 # consecutive PRs ``` ## Run History After each coverage analysis, append results to `run-history.json` in this skill directory: ```bash # Read current history, append new entry, write back node -e " const fs = require('fs'); const h = JSON.parse(fs.readFileSync('.claude/skills/qe-coverage-analysis/run-history.json')); h.runs.push({date: new Date().toISOString().split('T')[0], statements_pct: STATEMENTS, branches_pct: BRANCHES, gaps_found: GAPS}); fs.writeFileSync('.claude/skills/qe-coverage-analysis/run-history.json', JSON.stringify(h, null, 2)); " ``` Read `run-history.json` before each run to detect trends (e.g., "coverage dropped 3 consecutive times"). ## Skill Composition - **Coverage dropped?** → Use `/coverage-drop-investigator` to trace the cause - **Need more tests** → Use `/qe-test-generation` to fill gaps - **Validate quality** → Use `/mutation-testing` to ensure coverage means quality - **Ship decision** → Feed into `/qe-quality-assessment` for deployment readiness ## Gotchas - High line coverage does NOT mean good tests — 100% coverage with 0% assertions is common agent output. Use mutation testing to verify - coverage-analysis domain has 86% success rate — 14% of runs fail on initialization. Always verify results and have fallback plan (e.g. manual coverage tools) - Self-learning pipeline may silently stop learning (statusline frozen for days) — only human inspection catches this ## Coordination **Primary Agents**: qe-coverage-specialist, qe-coverage-analyzer, qe-gap-detector **Coordinator**: qe-coverage-coordinator **Related Skills**: qe-test-generation, qe-quality-assessment