Create a JavaScript Action

Use this template to bootstrap the creation of a JavaScript action.:rocket:

This template includes tests, linting, a validation workflow, publishing, and versioning guidance.

If you are new, there's also a simpler introduction. See the Hello World JavaScript Action

Create an action from this template

Click the Use this Template and provide the new repo details for your action

Code in Main

Install the dependencies

npm install

Run the tests ✔️

$ npm test

 PASS  ./index.test.js
  ✓ throws invalid number (3ms)
  ✓ wait 500 ms (504ms)
  ✓ test runs (95ms)
...

Change action.yml

The action.yml contains defines the inputs and output for your action.

Update the action.yml with your name, description, inputs and outputs for your action.

See the documentation

Change the Code

Most toolkit and CI/CD operations involve async operations so the action is run in an async function.

const core = require('@actions/core');
...

async function run() {
  try {
      ...
  }
  catch (error) {
    core.setFailed(error.message);
  }
}

run()

See the toolkit documentation for the various packages.

Package for distribution

GitHub Actions will run the entry point from the action.yml. Packaging assembles the code into one file that can be checked in to Git, enabling fast and reliable execution and preventing the need to check in node_modules.

Actions are run from GitHub repos. Packaging the action will create a packaged action in the dist folder.

Run prepare

npm run prepare

Since the packaged index.js is run from the dist folder.

git add dist

Create a release branch

Users shouldn't consume the action from master since that would be latest code and actions can break compatibility between major versions.

Checkin to the v1 release branch

git checkout -b v1
git commit -a -m "v1 release"

git push origin v1

Your action is now published! 🚀

See the versioning documentation

Usage

You can now consume the action by referencing the v1 branch

uses: actions/javascript-action@v1
with:
  milliseconds: 1000

See the actions tab for runs of this action! 🚀