runs-using-deno v1.2.2

Deno runtime for GitHub Actions

🦕 Write your GitHub Actions in Deno

import * as core from "npm:@actions/core@^1.10.1";
import * as github from "npm:@actions/github@^6.0.0";
console.log("github.context.payload", github.context.payload);
console.log(`Hello ${core.getInput("name")}!`);
core.setOutput("time", new Date().toLocaleTimeString());

✍ Lets you write your GitHub Actions using TypeScript \ 🚀 Supports node_modules-less development \ 🦕 Uses the Deno runtime for your GitHub Action \ 👨‍💻 Extremely hackish, but it works!

Installation

📋 Looking for a premade template? Check out jcbhmr/hello-world-deno-action!

Create _main.mjs (or some other .mjs file with main in it) and add this JavaScript code to it:

// _main.mjs
// https://github.com/jcbhmr/runs-using-deno
const response = await fetch("https://unpkg.com/runs-using-deno@1.2.2");
const buffer = Buffer.from(await response.arrayBuffer());
await import(`data:text/javascript;base64,${buffer.toString("base64")}`);

📌 Make sure you keep that pinned version up to date! 😉

wget https://unpkg.com/runs-using-deno -O _main.mjs

⚠️ The latest version of Deno will still be downloaded dynamically.

ℹ This tool sniffs the (main|pre|post) name from the process.argv[1] file (the entry point) so make sure you name your main: main.mjs something like _main.mjs or .main.mjs. It's recommended to use the .mjs extension so that the script is interpreted as ESM even when no Node.js package.json type: "module" is present.

Usage

To use this wrapper, add the following to your action.yml:

# action.yml
runs:
  using: node20
  main: _main.mjs
runs-using-deno:
  using: deno1
  main: main.ts

💡 Deno will auto-detect a deno.json Deno configuration file if it's near your main.ts Deno script. You can use this to provide an import map inside the deno.json to make importing the same libraries across multiple files easier.

// deno.json
{
  "imports": {
    "@actions/core": "npm:@actions/core@^1.10.1",
    "@actions/github": "npm:@actions/github@^6.0.0"
  }
}

// main.ts
import * as core from "@actions/core";
import * as github from "@actions/github";

pre-if and post-if

To get the native pre-if and post-if behaviour, you must specify these keys on the native runs YAML map instead of the custom runs-using-deno YAML map.

# action.yml
runs:
  using: node20
  main: _main.mjs
  pre: _pre.mjs
  post: _post.mjs

  pre-if: runner.os == 'Linux'
  post-if: runner.os == 'Windows'
runs-using-deno:
  using: deno1
  main: main.ts
  pre: pre.ts
  post: post.ts

You'll need to create _pre.mjs and _post.mjs files as separate entry points. All of these should import the same https://unpkg.com/runs-using-deno@1 module which will sniff the (main|pre|post) from the entry point file name and choose the right runs-using-deno-defined stage to run from there. Check out the test/ folder for a demo of an action using _main.mjs, _pre.mjs, and _post.mjs.

How it works

This is a wrapper Node.js script that downloads, installs, and caches the latest Deno version. Then, using the fields from action.yml, it executes Deno with the main: main.ts script as a subprocess. You automagically inherit all the environment variables, working directory, GitHub context, and more. It's pretty seamless! You can even use the @actions/core and other packages to interact as you would in Node.js. To learn more about how the Deno runtime works, check out the Deno manual.

Development

There's not really a good local test loop. The best way to test the code is to run the test/action.yml in GitHub Actions on each push or Pull Request. To test your changes, just push to the main branch or open a Pull Request (even a Draft one). 👍