How to cache node_modules on Github Actions

tl;dr

• Github will charge you by execution time, so apply this feature will reduce your invoice.
• This post shows a way to cache the node_modules during a Github Action execution.
• The benefits of ovoid the npm ci step can speed up the action execution.

Most of the Github Actions I've created are Node.js apps, so the npm install is always part of the requirements. I found this way to reduce the execution time by using the actions/cache@v2 cache action.

Just ovoid the npm ci entire action when the package-lock.json doesn't change.

- name: Cache dependencies
  id: cache
  uses: actions/cache@v2
  with:
    path: ./node_modules
    key: modules-${{ hashFiles('package-lock.json') }}



- name: Install dependencies
  if: steps.cache.outputs.cache-hit != 'true'
  run: npm ci

So this is the example of the Github Actions using cache.

name: CI

on: push


jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2


      - name: Setup Node.js
        uses: actions/setup-node@v2
        with:
          node-version: '16'


      - name: Cache dependencies
        id: cache
        uses: actions/cache@v2
        with:
          path: ./node_modules
          key: modules-${{ hashFiles('package-lock.json') }}


      - name: Install dependencies
        if: steps.cache.outputs.cache-hit != 'true'
        run: npm ci


      # ... here all the things related to the job, like test script, lint or deploy

Wrap up

This solution is could work or not for your project, keep in mind is just a way to do it.

The cache will last 7 days in Github, just keep that in mind.

So, let's reduce your Github invoice right now :D.

Happy coding!