'use strict' and Google AppsScript with V8 Runtime

README.md

Google V8 Engine and 'use strict'

Google V8 runtime by default is not run in strict mode.

Reproduce

The Function.apply method when run in strict mode returns the global context, so we can test with the given code.

• Execute testStrict()
• Check the Logs where __g__ is not null

Conclusion

The Google AppsScripts runtime is run in non-strict mode, and we can get access to global scope via this method.

Discussion

I was under the impression that ES6 was run in strict mode; I was mistaken. It's ES6 modules that are run in strict mode.

Code.js

function globalStrictMode_() {
  'use strict';
  return function () {
    return this;  // returns null in strict mode, global object if not
  }.apply(null, []);
}

function globalDefaultMode_() {
  return function () {
    return this;  // returns null in strict mode, global object if not
  }.apply(null, []);
}

function testStrict() {
  let __g__ = globalDefaultMode_();
  Logger.log(`is global null? ${__g__ == null}`);
  __g__ = globalStrictMode_();
  Logger.log(`is global null? ${__g__ == null}`);
}