Problem

shopify extension serve command is not supported for Shopify theme app extensions. As a solution, I created a simple Gulp task that automates pushing theme extension file updates automatically. With this approach, you will not have to cd to the theme-app-extension directory, nor will you need to run the shopify extension push command manually each time you make a change to your files.

Dependancies

1. node, npm, and npx

2. Add gulp.

   If gulp is not already installed follow the quick start instructions at https://gulpjs.com/docs/en/getting-started/quick-start to install Gulp in your project.

3. Add gulp-run by running command npm i gulp-run.

   gulp-run can be found at https://www.npmjs.com/package/gulp-run.

Install

1. Add gulpfile.js to root of your project.

2. Add "extension": "gulp" && "push:extension": "(cd ./theme-app-extension; shopify extension push)" commands to package.json file scripts.

   example:

   "scripts": {
    "extension": "gulp",
    "push:extension": "(cd ./theme-app-extension; shopify extension push)"
   }
   

3. Update your files pathes in the watcher(); function. By default, we watch for theme-app-extension/assets/*, theme-app-extension/blocks/*' and theme-app-extension/snippets/*. You may add or change these depending upon your requirements.

   example:

   const watcher = async (cb) => {
    watch('theme-app-extension/assets/*', push);
    watch('theme-app-extension/blocks/*', push);
    watch('theme-app-extension/snippets/*', push);
    cb();
   }
   

Usage

1. Open a new terminal in your project root and run npm run push:extension To run the Gulp process to automatically push, run npm run extension. (Note: You stay in the main app project root, you do not need to cd into theme-app-extension)
2. Upon save the script will now push theme extension updates to Shopify accordingly.

If you are already are using Gulp, skip install step #1 and download & include the script into your existing gulpfile.js. Then continue from steps #2 onward.

// Imports
const { series, watch } = require('gulp');
const run = require('gulp-run');

const watcher = async (cb) => {
  watch('theme-app-extension/assets/*', push);
  watch('theme-app-extension/blocks/*', push);
  watch('theme-app-extension/snippets/*', push);
  cb();
}

const push = async () => {
  const pushExtension = new run.Command('npm run push:extension');
  pushExtension.exec();
}

// Exports
exports.default = series(watcher);