Using a Composite Action in Workflow

Optimize your Node.js CI by extracting repeated caching and installation steps into a reusable composite action. This improves maintainability, reduces duplication, and speeds up workflow authorship.

Original Workflow Snippet

The following job explicitly checks out code, sets up Node.js, caches dependencies, installs packages, runs tests, and archives results:

runs-on: ${{ matrix.operating_system }}
strategy:
  matrix:
    operating_system: [ubuntu-latest]
    exclude:
      - nodejs_version: 18
        operating_system: macos-latest
    nodejs_version: [16, 18]
steps:
  - name: Checkout Repository
    uses: actions/checkout@v4

  - name: Setup Node.js – ${{ matrix.nodejs_version }}
    uses: actions/setup-node@v3
    with:
      node-version: ${{ matrix.nodejs_version }}

  - name: Cache NPM dependencies
    uses: actions/cache@v3
    with:
      path: node_modules
      key: ${{ runner.os }}-node-modules-${{ hashFiles('package-lock.json') }}

  - name: Install Dependencies
    run: npm install

  - name: Unit Testing
    id: nodejs-unit-testing
    run: npm test

  - name: Archive Test Results
    if: always()
    uses: actions/upload-artifact@v3
    with:
      name: Mocha-Test-Result
      path: test-results.xml

Replace Cache & Install with Composite Action

Instead of repeating the cache and install steps in every job, call your composite action:

steps:
  - name: Checkout Repository
    uses: actions/checkout@v4

  - name: Setup Node.js – ${{ matrix.nodejs_version }}
    uses: actions/setup-node@v3
    with:
      node-version: ${{ matrix.nodejs_version }}

  - name: Composite Action – Cache & Install NPM Packages
    uses: ./.github/custom-actions/npm-action

  - name: Unit Testing
    id: nodejs-unit-testing
    run: npm test

  - name: Archive Test Results
    if: always()
    uses: actions/upload-artifact@v3
    with:
      name: Mocha-Test-Result
      path: test-results.xml

Defining the Composite Action

Create .github/custom-actions/npm-action/action.yml to define inputs and steps:

name: 'NPM Custom Action'
description: 'Cache and install Node.js packages'
inputs:
  path-of-folder:
    description: 'Directory to cache (e.g., node_modules)'
    required: true
runs:
  using: 'composite'
  steps:
    - name: Cache NPM dependencies
      uses: actions/cache@v3
      with:
        path: ${{ inputs.path-of-folder }}
        key: ${{ runner.os }}-node-modules-${{ hashFiles('package-lock.json') }}

    - name: Install Dependencies
      run: npm install
      shell: bash

Supported Shells

Passing Inputs to the Composite Action

When calling the composite action, supply the path-of-folder input:

- name: Composite Action – Cache & Install NPM Packages
  uses: ./.github/custom-actions/npm-action
  with:
    path-of-folder: node_modules

You can also use expressions, variables, or secrets:

with:
  path-of-folder: ${{ vars.cache_path }}

Applying to a Code Coverage Job

Reuse the same composite action in a code-coverage job to cache dependencies before running coverage reports:

jobs:
  code-coverage:
    name: Code Coverage
    container:
      image: node:18
    steps:
      - name: Composite Action – Cache & Install NPM Packages
        uses: ./.github/custom-actions/npm-action
        with:
          path-of-folder: node_modules

      - name: Check Code Coverage
        continue-on-error: true
        run: npm run coverage

      - name: Archive Coverage Report
        uses: actions/upload-artifact@v3
        with:
          name: Code-Coverage-Result
          path: coverage
          retention-days: 5

Viewing Workflow Runs

After pushing your changes, navigate to the Actions tab in your repository to review each run, monitor status, and investigate logs:

Composite Action Logs

Expand the composite action step to view cache restoration and installation details:

Run ~/.github/custom-actions/npm-action
Run actions/cache@v3
Cache Size: ~7 MB (7028388 B)
/usr/bin/tar -xf /home/runner/work/_temp/.../cache.tzst -P -C /home/runner/work/solar-system/solar-system --use-compress-program unzstd
Cache restored successfully
Cache restored from key: Linux-node-modules-482579847a5939e157ee1a6b1d59e8f7f2b5e5f
Run npm install

Next Steps

This composite action lives in your repository and is available to all your workflows. To publish it to the GitHub Marketplace, explore these resources:

• Creating Docker container actions
• Writing JavaScript actions
• GitHub Actions Composite Run Steps