Dependency Resolver

Circular dependency detected:
  package-a → package-b → package-c → package-a

// package-a/index.js
const b = require('./package-b');

// package-b/index.js
const c = require('./package-c');

// package-c/index.js
const a = require('./package-a');  // Circular!

// Restructure to break cycle
// 1. Extract shared code to new package
// 2. Use dependency injection
// 3. Lazy loading

// Option 1: Extract shared functionality
// package-shared/index.js
module.exports = { sharedFunction };

// package-a/index.js
const shared = require('./package-shared');

// package-c/index.js
const shared = require('./package-shared');

{
  "dependencies": {
    "fsevents": "^2.3.2"  // macOS only
  }
}

npm ERR! notsup Unsupported platform for fsevents@2.3.2

{
  "dependencies": {
    "chokidar": "^3.5.3"  // Cross-platform alternative
  },
  "optionalDependencies": {
    "fsevents": "^2.3.2"  // macOS optimization
  }
}

# Check installed package sizes
npm ls --all --depth=0
du -sh node_modules/

# Result: 500MB for small app!

npx cost-of-modules

┌────────────────────────┬───────────┬────────────┐
│ name                   │ size      │ dependencies│
├────────────────────────┼───────────┼────────────┤
│ @babel/core            │ 45 MB     │ 234        │
│ webpack                │ 38 MB     │ 189        │
│ lodash                 │ 1.5 MB    │ 0          │
└────────────────────────┴───────────┴────────────┘

// Use lighter alternatives
{
  "dependencies": {
    "lodash.debounce": "^4.0.8",  // Instead of full lodash
    "date-fns": "^2.29.3"         // Instead of moment.js
  }
}

// Remove unused dependencies
// Use: npm prune
// Or: yarn autoclean

^1.2.3   - Compatible with 1.2.3 (>=1.2.3 <2.0.0)
~1.2.3   - Approximately 1.2.3 (>=1.2.3 <1.3.0)
1.2.x    - 1.2.0, 1.2.1, etc. (>=1.2.0 <1.3.0)
*        - Any version
latest   - Latest version
1.2.3    - Exact version
>=1.2.3  - Greater than or equal
<2.0.0   - Less than
1.2.3 - 2.3.4  - Range

==1.2.3      - Exact version
>=1.2.3      - Minimum version
>=1.2,<2.0   - Range
~=1.2.3      - Compatible release (>=1.2.3, ==1.2.*)
!=1.2.3      - Exclude version
package      - Any version

<version>1.2.3</version>           <!-- Exact -->
<version>[1.2.3]</version>         <!-- Exact (hard) -->
<version>[1.0,2.0)</version>       <!-- Range: 1.0 <= x < 2.0 -->
<version>[1.0,)</version>          <!-- Minimum 1.0 -->
<version>(,2.0)</version>          <!-- Maximum < 2.0 -->

[dependencies]
package = "1.2.3"        # Exact: =1.2.3
package = "^1.2.3"       # Caret: >=1.2.3, <2.0.0
package = "~1.2.3"       # Tilde: >=1.2.3, <1.3.0
package = ">= 1.2.3"     # Inequality
package = "*"            # Any version

# Install dependencies
npm install
yarn install

# Add dependency
npm install package-name
yarn add package-name

# Add dev dependency
npm install --save-dev package-name
yarn add --dev package-name

# Update dependencies
npm update
yarn upgrade

# Check for outdated
npm outdated
yarn outdated

# Security audit
npm audit
yarn audit

# Fix vulnerabilities
npm audit fix
yarn audit fix

# List dependencies
npm ls
yarn list

# Remove unused
npm prune
yarn autoclean

# Lock file
npm ci  # Clean install from lock file
yarn install --frozen-lockfile

# Install dependencies
pip install -r requirements.txt

# Install package
pip install package-name

# Install specific version
pip install package-name==1.2.3

# Upgrade package
pip install --upgrade package-name

# List installed
pip list

# Show outdated
pip list --outdated

# Security check
pip-audit  # Requires pip-audit package

# Freeze dependencies
pip freeze > requirements.txt

# Uninstall
pip uninstall package-name

# Install dependencies
mvn install

# Update dependencies
mvn versions:update-properties

# Dependency tree
mvn dependency:tree

# Analyze dependencies
mvn dependency:analyze

# Check for updates
mvn versions:display-dependency-updates

# Security check (with OWASP plugin)
mvn dependency-check:check

# Install dependencies
go mod download

# Add dependency
go get package-name

# Update dependencies
go get -u ./...

# Tidy dependencies
go mod tidy

# Verify dependencies
go mod verify

# List dependencies
go list -m all

# Dependency graph
go mod graph

# Security check
go list -json -m all | nancy sleuth

# Verify all dependencies install successfully
npm ci  # or equivalent for your package manager

# Check for installation errors
echo $?  # Should be 0

# Run security audit
npm audit

# Check for high/critical vulnerabilities
# Fix if found
npm audit fix

# Check licenses
npx license-checker --summary

# Verify no GPL or incompatible licenses
npx license-checker --excludeLicenses "GPL,AGPL"

# Check for duplicate packages
npm dedupe

# Verify no circular dependencies
npm ls

# Check tree depth
npm ls --depth=5

# Test on target platform
# Verify OS-specific dependencies work
# Check architecture compatibility (x64, arm64)

# Ensure lock file is committed
git ls-files package-lock.json

# Verify lock file is up to date
npm ci

# Check total size
du -sh node_modules/

# Identify large packages
npx cost-of-modules

# Remove dev dependencies for production
npm prune --production

Error: Cannot find module 'express'

# Install missing package
npm install express

# Add to package.json
npm install express --save

# Reinstall all dependencies
rm -rf node_modules
npm install

npm ERR! peer dep missing: react@>=16.0.0

# Check peer dependencies
npm info package-name peerDependencies

# Install required peer dependency
npm install react@^16.0.0

npm ERR! package-lock.json lockfileVersion mismatch

# Delete and regenerate
rm package-lock.json
npm install

# Or use correct npm version
nvm use 16
npm install

npm ERR! network timeout

# Increase timeout
npm config set timeout 60000

# Try different registry
npm config set registry https://registry.npmjs.org/

# Clear cache
npm cache clean --force

npm ERR! postinstall script failed

# Check node/npm version
node --version
npm --version

# Update build tools
npm install -g node-gyp

# Install system dependencies (example for Ubuntu)
sudo apt-get install build-essential python3