Testability Scoring

Browser engine

Uses the qe-browser fleet skill (.claude/skills/qe-browser/) as the primary browser engine. Vibium is installed by aqe init. The legacy scripts/run-assessment.sh + Playwright path remains as a fallback when a team already has a Playwright test suite configured, but new runs should prefer:

vibium go "$TARGET_URL"
vibium wait load
vibium a11y-tree --json > /tmp/testability/tree.json
vibium eval --stdin --json <<'EOF' > /tmp/testability/signals.json
JSON.stringify({
  headings: document.querySelectorAll('h1,h2,h3,h4,h5,h6').length,
  testIds: document.querySelectorAll('[data-testid]').length,
  forms: document.querySelectorAll('form').length,
  ariaLabels: document.querySelectorAll('[aria-label]').length,
  links: document.querySelectorAll('a[href]').length,
});
EOF
node .claude/skills/qe-browser/scripts/assert.js --checks '[
  {"kind": "no_console_errors"},
  {"kind": "no_failed_requests"}
]'

<default_to_action> When assessing testability:

1. RUN assessment against target URL
2. ANALYZE all 10 principles automatically
3. GENERATE HTML report with radar chart
4. PRIORITIZE improvements by impact/effort
5. INTEGRATE with QX Partner for holistic view

Quick Assessment:

# Run assessment on any URL
TEST_URL='https://example.com/' npx playwright test tests/testability-scoring/testability-scoring.spec.js --project=chromium --workers=1

# Or use shell script wrapper
.claude/skills/testability-scoring/scripts/run-assessment.sh https://example.com/

The 10 Principles at a Glance:

Principle	Weight	Key Question
Observability	15%	Can we see what's happening?
Controllability	15%	Can we control the application?
Algorithmic Simplicity	10%	Are behaviors predictable?
Algorithmic Transparency	10%	Can we understand what it does?
Algorithmic Stability	10%	Does behavior remain consistent?
Explainability	10%	Is the interface understandable?
Unbugginess	10%	How error-free is it?
Smallness	10%	Are components appropriately sized?
Decomposability	5%	Can we test parts in isolation?
Similarity	5%	Is the tech stack familiar?

Grade Scale:

• A (90-100): Excellent testability
• B (80-89): Good testability
• C (70-79): Adequate testability
• D (60-69): Below average
• F (0-59): Poor testability </default_to_action>

Quick Reference Card

Running Assessments

Method	Command	When to Use
Shell Script	./scripts/run-assessment.sh URL	One-time assessment
ENV Override	TEST_URL='URL' npx playwright test...	CI/CD integration
Config File	Update tests/testability-scoring/config.js	Repeated runs

Principle Details

High Weight (15% each)

Principle	Measures	Indicators
Observability	State visibility, logging, monitoring	Console output, network tracking, error visibility
Controllability	Input control, state manipulation	API access, test data injection, determinism

Medium Weight (10% each)

Principle	Measures	Indicators
Simplicity	Predictable behavior	Clear I/O relationships, low complexity
Transparency	Understanding what system does	Visible processes, readable code
Stability	Consistent behavior	Change resilience, maintainability
Explainability	Interface understanding	Good docs, semantic structure, help text
Unbugginess	Error-free operation	Console errors, warnings, runtime issues
Smallness	Component size	Element count, script bloat, page complexity

Low Weight (5% each)

Principle	Measures	Indicators
Decomposability	Isolation testing	Component separation, modular design
Similarity	Technology familiarity	Standard frameworks, known patterns

---

Assessment Workflow

1. Navigate to URL → 2. Collect Metrics → 3. Score Principles
                                              ↓
4. Generate JSON ← 5. Calculate Grades ← 6. Apply Weights
         ↓
7. Generate HTML Report with Radar Chart
         ↓
8. Open in Browser (auto-opens)

Output Files

tests/reports/
├── testability-results-<timestamp>.json  # Raw data
├── testability-report-<timestamp>.html   # Visual report
└── latest.json                           # Symlink

---

Integration Examples

CI/CD Integration

# GitHub Actions
- name: Testability Assessment
  run: |
    timeout 180 .claude/skills/testability-scoring/scripts/run-assessment.sh ${{ env.APP_URL }}

- name: Upload Reports
  uses: actions/upload-artifact@v3
  with:
    name: testability-reports
    path: tests/reports/testability-*.html

QX Partner Integration

// Combine testability with QX analysis
const qxAnalysis = await Task("QX Analysis", {
  target: 'https://example.com',
  integrateTestability: true
}, "qx-partner");

// Returns combined insights:
// - QX Score: 78/100
// - Testability Integration: Observability 72/100
// - Combined Insight: Low observability may mask UX issues

Programmatic Usage

import { runTestabilityAssessment } from './testability';

const results = await runTestabilityAssessment('https://example.com');
console.log(`Overall: ${results.overallScore}/100 (${results.grade})`);
console.log('Recommendations:', results.recommendations);

---

Agent Integration

// Run testability assessment
const assessment = await Task("Testability Assessment", {
  url: 'https://example.com',
  generateReport: true,
  openBrowser: true
}, "qe-quality-analyzer");

// Use with QX Partner for holistic analysis
const qxReport = await Task("Full QX Analysis", {
  target: 'https://example.com',
  integrateTestability: true,
  detectOracleProblems: true
}, "qx-partner");

---

Vibium Integration (Optional)

Overview

Vibium browser automation can be used alongside Playwright for enhanced testability assessment. While Playwright remains the primary engine, Vibium offers complementary capabilities for certain metrics.

Installation:

claude mcp add vibium -- npx -y vibium

Vibium-Enhanced Metrics

Principle	Vibium Enhancement	Benefit
Observability	Auto-wait duration tracking	Measures DOM stability (30s timeout, 100ms polling)
Controllability	Element interaction success rate	Validates automation readiness via MCP
Stability	Screenshot consistency	Visual regression detection for layout stability
Explainability	Element attribute extraction	ARIA labels, semantic HTML validation

When to Use Vibium

✅ USE Vibium for:

• Element stability metrics (auto-wait duration analysis)
• Visual consistency checks (screenshot comparison)
• MCP-native AI agent integration
• Lightweight Docker images (400MB vs 1.2GB)

❌ USE Playwright for:

• Console error detection (Vibium V1 lacks console API)
• Network performance metrics (BiDi network APIs coming in V2)
• Comprehensive browser coverage (Firefox, Safari)
• Production-proven stability (Vibium V1 released Dec 2024)

Hybrid Assessment Example

// Testability assessment using both engines
const assessment = {
  // Playwright: Comprehensive metrics
  playwright: await runPlaywrightAssessment(url),

  // Vibium: Stability metrics
  vibium: {
    elementStability: await measureAutoWaitDuration(url),
    visualConsistency: await compareScreenshots(url),
    accessibilityAttributes: await extractARIALabels(url)
  }
};

// Enhanced Observability Score
const observability =
  (assessment.playwright.consoleErrors * 0.6) +
  (assessment.vibium.elementStability * 0.4);

Vibium MCP Tools for Testability

// 1. Element Stability Measurement
const browser = await browser_launch();
await browser_navigate({ url });
const startTime = Date.now();
const element = await browser_find({ selector: ".critical-element" });
const autoWaitDuration = Date.now() - startTime;
// Lower duration = better stability

// 2. Visual Consistency Check
const screenshot1 = await browser_screenshot();
await browser_navigate({ url }); // Reload
const screenshot2 = await browser_screenshot();
const visualDiff = compareImages(screenshot1.png, screenshot2.png);
// Lower diff = better stability

// 3. Accessibility Attribute Extraction
const elements = await browser_find({ selector: "button, a, input" });
const ariaLabels = elements.map(el => el.attributes["aria-label"]);
const semanticScore = (ariaLabels.filter(Boolean).length / elements.length) * 100;

Migration Strategy

Current (V2.2): Hybrid approach

• Playwright: Primary engine for all 10 principles
• Vibium: Optional enhancement for stability metrics

Future (V3.0): When Vibium V2 ships

• Evaluate Vibium as primary engine if:
  • Console/Network APIs available
  • Production stability proven
  • Community adoption increases

Agent Coordination Hints

Memory Namespace

aqe/testability/
├── assessments/*       - Assessment results by URL
├── historical/*        - Historical scores for trend analysis
├── recommendations/*   - Improvement recommendations
├── integration/*       - QX integration data
└── vibium/*           - Vibium-specific metrics (optional)

Fleet Coordination

const testabilityFleet = await FleetManager.coordinate({
  strategy: 'testability-assessment',
  agents: [
    'qe-quality-analyzer',  // Primary assessment
    'qx-partner',           // UX integration
    'qe-visual-tester'      // Visual validation
  ],
  topology: 'sequential'
});

---

Common Issues & Solutions

Issue	Solution
Tests timing out	Increase timeout: timeout 300 ./scripts/run-assessment.sh URL
Partial results	Check console errors, increase network timeout
Report not opening	Use AUTO_OPEN=false, open manually
Config not updating	Use TEST_URL env var instead
Vibium not available	Install via claude mcp add vibium -- npx -y vibium (optional)
Hybrid mode errors	Vibium is optional; assessments work without it

---

Related Skills

• accessibility-testing - WCAG compliance (overlaps with Explainability)
• visual-testing-advanced - UI consistency
• performance-testing - Load time metrics

---

Credits & References

Framework Origin

• Heuristics for Software Testability by James Bach and Michael Bolton
• Available at: https://www.satisfice.com/download/heuristics-of-software-testability

Implementation

• Based on https://github.com/fndlalit/testability-scorer (contributed by @fndlalit)
• Playwright v1.49.0+ with AI capabilities (primary engine)
• Vibium v1.0+ with MCP integration (optional enhancement)
• Chart.js for radar visualizations

Vibium Resources

• GitHub: https://github.com/VibiumDev/vibium
• MCP Integration: claude mcp add vibium -- npx -y vibium
• Created by Jason Huggins (creator of Selenium/Appium)

---

Remember

Testability is an investment, not an afterthought.

Good testability:

• Reduces debugging time
• Enables faster feedback loops
• Makes defects easier to find
• Supports continuous testing

Low scores = High risk. Prioritize improvements by weight × impact.