TypeScript support

[grant]

Expected Behavior

You should be able to code Apps Script locally with autocompleting types. This is the main advantage of using script.google.com IMO.

Actual Behavior

You can use clasp to download/upload projects, but it's not feasible to develop Apps Script locally.

Implementation

Transpile all ts files clasp push.

var ts = require('typescript');
// https://www.typescriptlang.org/docs/handbook/compiler-options.html
var t = ts.transpile(s, {
  // strict: true,
  target: 'ES3',
  lib: ["es2015"],
  // removeComments: true,
});

Caveat: You can't clasp pull to update ts files, but we're moving away the Apps Script editor anyways.

[grant]

Provide a guide like this:
https://firebase.google.com/docs/functions/typescript

[FiloSottile]

You can get very good TypeScript support by installing types and compiling before pushing. https://blog.filippo.io/gmail-bot-with-apps-script-and-typescript/

[gauntface]

It would be great if this could be officially supported with types provided by the appscript / clasp team.

[grant]

TypeScript is supported with clasp@1.5 🎉

The supported types are at @types/google-apps-script. I'll update that package with updated Apps Script types every so often.

Please report issues with the types in the types source code: https://github.com/DefinitelyTyped/DefinitelyTyped

Closing as fixed.