Supporting material availability

This catalog copy contains the inline guidance below, but does not include the following supporting paths. They are external prerequisites, not bundled files:

• <support-root>/references/semver.md
• <support-root>/references/compatibility-matrix.md
• <support-root>/references/staged-upgrades.md
• <support-root>/references/testing-strategy.md
• <support-root>/assets/upgrade-checklist.md
• <support-root>/assets/compatibility-matrix.csv
• <support-root>/scripts/audit-dependencies.sh

Ask for the original supporting material or an existing installation before using a step that depends on these paths; this catalog does not identify a verified download source for them. Resolve each path relative to that installation, inspect its contents, and verify any applicable license and execution prerequisites. Do not run a command or claim a referenced procedure was followed until its required file exists. Do not fabricate the missing scripts or treat an unrelated file with the same name as equivalent. Independent steps fully documented here can proceed within the user’s authorized scope; report any dependent step as unavailable.

Dependency Upgrade

Master major dependency version upgrades, compatibility analysis, staged upgrade strategies, and comprehensive testing approaches.

Do not use this skill when

• The task is unrelated to dependency upgrade
• You need a different domain or tool outside this scope

Instructions

• Clarify goals, constraints, and required inputs.
• Apply relevant best practices and validate outcomes.
• Provide actionable steps and verification.

Use this skill when

• Upgrading major framework versions
• Updating security-vulnerable dependencies
• Modernizing legacy dependencies
• Resolving dependency conflicts
• Planning incremental upgrade paths
• Testing compatibility matrices
• Automating dependency updates

Semantic Versioning Review

MAJOR.MINOR.PATCH (e.g., 2.3.1)

MAJOR: Breaking changes
MINOR: New features, backward compatible
PATCH: Bug fixes, backward compatible

^2.3.1 = >=2.3.1 <3.0.0 (minor updates)
~2.3.1 = >=2.3.1 <2.4.0 (patch updates)
2.3.1 = exact version

Separate inspection from mutation: npm audit fix/dedupe, yarn dedupe and ncu -u change dependency state. Pin and review codemods/CLI packages before running; the changelog-parser/react-codeshift command shapes below are illustrative and must be checked against the actual official tool, not assumed runnable. Regex migration is not syntax-aware and can corrupt strings/comments/imports; use reviewed AST transforms and inspect every diff. SemVer promises do not prove compatibility and caret rules differ below 1.0. Select exact targets from release notes/peer requirements instead of latest. --force/--legacy-peer-deps bypass protections rather than resolve incompatibility. A matching React version or DOM snapshot is not full runtime/visual verification. Do not overwrite an existing UPGRADE_PLAN.md or enable automerge implicitly.

Dependency Analysis

Audit Dependencies

# npm
npm outdated
npm audit
npm audit fix

# yarn
yarn outdated
yarn audit

# Check for major updates
npx npm-check-updates
npx npm-check-updates -u  # Update package.json

Analyze Dependency Tree

# See why a package is installed
npm ls package-name
yarn why package-name

# Find duplicate packages
npm dedupe
yarn dedupe

# Visualize dependencies
npx madge --image graph.png src/

Compatibility Matrix

// compatibility-matrix.js
const compatibilityMatrix = {
  'react': {
    '16.x': {
      'react-dom': '^16.0.0',
      'react-router-dom': '^5.0.0',
      '@testing-library/react': '^11.0.0'
    },
    '17.x': {
      'react-dom': '^17.0.0',
      'react-router-dom': '^5.0.0 || ^6.0.0',
      '@testing-library/react': '^12.0.0'
    },
    '18.x': {
      'react-dom': '^18.0.0',
      'react-router-dom': '^6.0.0',
      '@testing-library/react': '^13.0.0'
    }
  }
};

function checkCompatibility(packages) {
  // Validate package versions against matrix
}

Staged Upgrade Strategy

Phase 1: Planning

# 1. Identify current versions
npm list --depth=0

# 2. Check for breaking changes
# Read CHANGELOG.md and MIGRATION.md

# 3. Create upgrade plan
echo "Upgrade order:
1. TypeScript
2. React
3. React Router
4. Testing libraries
5. Build tools" > UPGRADE_PLAN.md

Phase 2: Incremental Updates

# Don't upgrade everything at once!

# Step 1: Update TypeScript
npm install typescript@latest

# Test
npm run test
npm run build

# Step 2: Update React (one major version at a time)
npm install react@17 react-dom@17

# Test again
npm run test

# Step 3: Continue with other packages
npm install react-router-dom@6

# And so on...

Phase 3: Validation

// tests/compatibility.test.js
describe('Dependency Compatibility', () => {
  it('should have compatible React versions', () => {
    const reactVersion = require('react/package.json').version;
    const reactDomVersion = require('react-dom/package.json').version;

    expect(reactVersion).toBe(reactDomVersion);
  });

  it('should not have peer dependency warnings', () => {
    // Run npm ls and check for warnings
  });
});

Breaking Change Handling

Identifying Breaking Changes

# Use changelog parsers
npx changelog-parser react 16.0.0 17.0.0

# Or manually check
curl https://raw.githubusercontent.com/facebook/react/main/CHANGELOG.md

Codemod for Automated Fixes

# React upgrade codemods
npx react-codeshift <transform> <path>

# Example: Update lifecycle methods
npx react-codeshift \
  --parser tsx \
  --transform react-codeshift/transforms/rename-unsafe-lifecycles.js \
  src/

Custom Migration Script

// migration-script.js
const fs = require('fs');
const glob = require('glob');

glob('src/**/*.tsx', (err, files) => {
  files.forEach(file => {
    let content = fs.readFileSync(file, 'utf8');

    // Replace old API with new API
    content = content.replace(
      /componentWillMount/g,
      'UNSAFE_componentWillMount'
    );

    // Update imports
    content = content.replace(
      /import { Component } from 'react'/g,
      "import React, { Component } from 'react'"
    );

    fs.writeFileSync(file, content);
  });
});

Testing Strategy

Unit Tests

// Ensure tests pass before and after upgrade
npm run test

// Update test utilities if needed
npm install @testing-library/react@latest

Integration Tests

// tests/integration/app.test.js
describe('App Integration', () => {
  it('should render without crashing', () => {
    render(<App />);
  });

  it('should handle navigation', () => {
    const { getByText } = render(<App />);
    fireEvent.click(getByText('Navigate'));
    expect(screen.getByText('New Page')).toBeInTheDocument();
  });
});

Visual Regression Tests

// visual-regression.test.js
describe('Visual Regression', () => {
  it('should match snapshot', () => {
    const { container } = render(<App />);
    expect(container.firstChild).toMatchSnapshot();
  });
});

E2E Tests

// cypress/e2e/app.cy.js
describe('E2E Tests', () => {
  it('should complete user flow', () => {
    cy.visit('/');
    cy.get('[data-testid="login"]').click();
    cy.get('input[name="email"]').type('user@example.com');
    cy.get('button[type="submit"]').click();
    cy.url().should('include', '/dashboard');
  });
});

Automated Dependency Updates

Renovate Configuration

// renovate.json
{
  "extends": ["config:base"],
  "packageRules": [
    {
      "matchUpdateTypes": ["minor", "patch"],
      "automerge": false
    },
    {
      "matchUpdateTypes": ["major"],
      "automerge": false,
      "labels": ["major-update"]
    }
  ],
  "schedule": ["before 3am on Monday"],
  "timezone": "America/New_York"
}

Dependabot Configuration

# .github/dependabot.yml
version: 2
updates:
  - package-ecosystem: "npm"
    directory: "/"
    schedule:
      interval: "weekly"
    open-pull-requests-limit: 5
    reviewers:
      - "team-leads"
    commit-message:
      prefix: "chore"
      include: "scope"

Rollback Plan

# Work on a topic branch with a clean or separately preserved starting state.
# Record the original full commit SHA and lockfile before changing dependencies.
# If validation fails, keep the failed diff and logs for diagnosis.
# Review and revert only task-owned manifest/lockfile changes when appropriate,
# then use npm ci to restore the recorded lockfile; never delete the branch or others' work.

Common Upgrade Patterns

Lock File Management

# npm
npm install --package-lock-only  # Update lock file only
npm ci  # Clean install from lock file

# yarn
yarn install --frozen-lockfile  # CI mode
yarn upgrade-interactive  # Interactive upgrades

Peer Dependency Resolution

# npm 7+: strict peer dependencies
npm install --legacy-peer-deps  # Ignore peer deps

# npm 8+: override peer dependencies
npm install --force

Workspace Upgrades

# Update all workspace packages
npm install --workspaces

# Update specific workspace
npm install package@latest --workspace=packages/app

Resources

• references/semver.md: Semantic versioning guide
• references/compatibility-matrix.md: Common compatibility issues
• references/staged-upgrades.md: Incremental upgrade strategies
• references/testing-strategy.md: Comprehensive testing approaches
• assets/upgrade-checklist.md: Step-by-step checklist
• assets/compatibility-matrix.csv: Version compatibility table
• scripts/audit-dependencies.sh: Dependency audit script

Best Practices

1. Read Changelogs: Understand what changed
2. Upgrade Incrementally: One major version at a time
3. Test Thoroughly: Unit, integration, E2E tests
4. Check Peer Dependencies: Resolve conflicts early
5. Use Lock Files: Ensure reproducible installs
6. Automate Updates: Use Renovate or Dependabot
7. Monitor: Watch for runtime errors post-upgrade
8. Document: Keep upgrade notes

Upgrade Checklist

Pre-Upgrade:
- [ ] Review current dependency versions
- [ ] Read changelogs for breaking changes
- [ ] Create feature branch
- [ ] Backup current state (git tag)
- [ ] Run full test suite (baseline)

During Upgrade:
- [ ] Upgrade one dependency at a time
- [ ] Update peer dependencies
- [ ] Fix TypeScript errors
- [ ] Update tests if needed
- [ ] Run test suite after each upgrade
- [ ] Check bundle size impact

Post-Upgrade:
- [ ] Full regression testing
- [ ] Performance testing
- [ ] Update documentation
- [ ] Deploy to staging
- [ ] Monitor for errors
- [ ] Deploy to production

Common Pitfalls

• Upgrading all dependencies at once
• Not testing after each upgrade
• Ignoring peer dependency warnings
• Forgetting to update lock file
• Not reading breaking change notes
• Skipping major versions
• Not having rollback plan

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.