App Script Starter Project

This is a sample apps script starter project that enables use of modern JS tooling for both Apps Script and client-side development.

The starter project demonstrates:

• Typescript for Apps Script & client-side scripts
• Rollup for bundling. This allows the use of ES modules as well as import NPM packages for both apps script and client-side scripts
• Clasp to deploy to apps script
• Lit for client-side Web Components
• Example of displaying HTML UIs in bound scripts and editor add-ons
• OAuth example code

Setup

For development:

• Create a new Google Sheet and bound script..
• Edit .clasp.dev.json and replace the scriptId property with the ID of your script.

For production:

• Create a standalone script.
• Edit .clasp.json and replace the scriptId property with the ID of your script.

Building

1. Install dependencies:

npm i

1. Build the app:

npm run build

1. Deploy

For development:

npm run deploy:dev

For production:

npm run deploy

Building in watch mode

Use npm run deploy:watch to run in watch mode. The add-on will be continually built and deployed to the development script whenever local files are changed.

Project structure

• ./pages/ contains client-side HTML, javascript, and CSS files.
• ./server/ contains apps-script code executed server side
• ./shared/ contains shared files used across both environments

Rollup.js config

While Apps Script supports most modern Javascript syntax, the environment itself imposes several constraints that that need to be accounted for when developing:

• Modules are not supported. All script files exist in the same namespace.
• While HTML content can be served, other resources such as raw javascript and CSS files can not.
• Built-ins are different from standard browser & Node.js environments.

That said, tools like Rollup.js help bridge those gaps, allowing add-ons to be developed using modern syntax and module support.

The rollup.config.js contains rules for processing source files to make them compatible with the Apps Script environment.

For Apps Script code:

• The @rollup/plugin-typescript plugin enables Typescript support.
• The @rollup/plugin-node-resolve plugin allows importing NPM packages. Any package that does not rely on node or browser globals should work correctly. Imported packages are inlined in the transpiled script.

For client-side HTML:

• Both Typescript & Node resolution modules are enabled
• The @web/rollup-plugin-html plugin is used to process any local CSS and JS files included in HTML files. This is combined with an extension to inline those resources so they're served as a single file.
• Each HTML file is defined as a separate entry point to prevent chunking of shared code.

The dist/ directory contains the transpiled code after the build is run.