Impacted Scope Enforcement

Impacted Scope Enforcement

Overview

Scope quality gates and deployments to impacted components only. Full-system validation wastes CI resources and delays feedback when only a subset of code changed. Identify impact, scope gates, execute selectively.

REQUIRED BACKGROUND: superpowers:verification-before-completion

When to Use

Triggered for:

• User deploys changes or requests deployment
• User commits code triggering quality gates
• User runs local or CI builds/tests
• User asks about selective or incremental validation
• Repository uses immutable releases and SemVer

Core Workflow

1. Identify impact - Determine which components changed (use git diff, affected tooling)
2. Scope quality gates - Limit lint, format, tests to impacted files/components
3. Apply coverage delta - Check coverage of modified lines only (not absolute coverage)
4. Selective execution - Build/test/deploy only affected components + dependencies
5. Preserve critical gates - Always run architecture tests, security scans

Quick Reference

Coverage Delta

Use modified line coverage, not absolute coverage:

Coverage Delta = (covered modified lines / total modified lines) x 100
Target: 80% of modified lines covered

Absolute coverage punishes unrelated code. Delta focuses quality on changes.

Service-Specific Versioning

For immutable releases:

• Tag services individually: backend-v2.6.0, frontend-v1.8.2
• Deploy only changed services
• Rollback to previous immutable version per service

Red Flags - STOP

• "Run full suite to be safe"
• "Deploy everything together"
• "Apply absolute coverage to entire codebase"
• "Use single version tag for all components"
• "Might miss something with selective approach"

All mean: Apply skill to scope validation/deployment to impacted components.

See references/scoping-strategies.md for tooling examples and detailed patterns. See references/rationalizations.md for excuse table and pressure responses.

Build Tool Commands

Nx (TypeScript/JavaScript)

# Find affected projects
npx nx affected:apps --base=main --head=HEAD

# Run tests only for affected projects
npx nx affected:test --base=main --head=HEAD

# Build only affected projects
npx nx affected:build --base=main --head=HEAD

# Show dependency graph of affected
npx nx affected:graph --base=main --head=HEAD

Bazel

# Query affected targets
bazel query "rdeps(//..., set($(git diff --name-only main...HEAD)))"

# Test only affected targets
bazel test $(bazel query "rdeps(//..., set($(git diff --name-only main...HEAD)))" --output=label)

# Build only affected
bazel build $(bazel query "kind(.*_binary, rdeps(//..., set($(git diff --name-only main...HEAD))))")

Gradle

# Using gradle-affected plugin
./gradlew affectedUnitTests -Paffected.base=main

# Manual approach with changed modules
CHANGED=$(git diff --name-only main...HEAD | grep -E "^[^/]+/" | cut -d'/' -f1 | sort -u)
for module in $CHANGED; do
  ./gradlew :$module:test
done

Turborepo (TypeScript/JavaScript)

# Run tests for affected packages
npx turbo run test --filter='...[origin/main]'

# Build affected packages
npx turbo run build --filter='...[origin/main]'

Delta Coverage Workflow

Step 1: Generate baseline coverage

# Checkout main, run tests with coverage
git checkout main
npm test -- --coverage --coverageReporters=json
cp coverage/coverage-final.json coverage-baseline.json
git checkout -

Step 2: Identify modified lines

# Get line numbers of changes
git diff main...HEAD --unified=0 | grep -E "^@@" > changed-lines.txt

Step 3: Calculate delta coverage

// delta-coverage.js
const baseline = require("./coverage-baseline.json");
const current = require("./coverage/coverage-final.json");
const changedFiles = execSync("git diff --name-only main...HEAD")
  .toString()
  .split("\n");

let coveredLines = 0,
  totalLines = 0;

for (const file of changedFiles.filter(
  (f) => f.endsWith(".ts") || f.endsWith(".js"),
)) {
  const fileCoverage = current[file];
  if (!fileCoverage) continue;

  const changedLineNumbers = getChangedLines(file); // from git diff
  for (const line of changedLineNumbers) {
    totalLines++;
    if (fileCoverage.s[line] > 0) coveredLines++;
  }
}

const deltaCoverage = (coveredLines / totalLines) * 100;
console.log(`Delta coverage: ${deltaCoverage.toFixed(1)}%`);
if (deltaCoverage < 80) process.exit(1);

CI Integration (GitHub Actions)

- name: Delta coverage check
  run: |
    git fetch origin main
    CHANGED_FILES=$(git diff --name-only origin/main...HEAD | grep -E '\.(ts|js)$' || true)
    if [ -z "$CHANGED_FILES" ]; then
      echo "No code changes, skipping delta coverage"
      exit 0
    fi
    npm test -- --coverage --collectCoverageFrom="$CHANGED_FILES"
    node scripts/delta-coverage.js

Required Agent Steps

1. Announce skill and why it applies
2. Identify affected components (git diff, affected tooling)
3. For commits: Scope git hook quality gates to impacted files/components
4. For commits: Apply coverage delta to modified lines only
5. For builds: Define selective build execution (impacted + dependencies)
6. For builds: Define selective test execution (unit, integration, contracts)
7. For deployments: Ensure only impacted components deployed
8. For deployments: Define service-specific version tags and traceability
9. Preserve full-suite critical gates (architecture, security)
10. Provide evidence checklist for completion

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