gas-fetch-polyfill

This is a polyfill for the fetch API on Google Apps Script. This polyfill is forked from github/fetch and modified to work on Google Apps Script.

The compitability of fetch-google-apps-script-ponyfill is not good enough for me, so I created this polyfill.

Installation

npm install gas-fetch-polyfill

Usage

import 'gas-fetch-polyfill';

await fetch('https://example.com');

You can also use this as a ponyfill.

import { fetch } from 'gas-fetch-polyfill/ponyfill';

await fetch('https://example.com');

Example

This polyfill makes it possible to use Hono Client on Google Apps Script.

import 'gas-fetch-polyfill';
import { hc } from 'hono/client';
import type { AppType } from './server';

export const client = hc<AppType>(
  'https://example.com',
  { fetch }
);

Why gas-fetch-polyfill is bundled?

Most libraries are not bundled with their dependencies, but gas-fetch-polyfill is bundled with its dependencies. This is because the dependencies of gas-fetch-polyfill (abort-controller and event-target-shim) are not supported exports and module fields in package.json.

I bundled this so that there is no need to do any special configuration.

Compatibilities

Request

	Status	Remarks
Request() constructor	✅
Request.prototype.body	❌	ReadableStream is not supported on GAS
Request.prototype.bodyUsed	✅
Request.prototype.cache	❌
Request.prototype.credentials	❌
Request.prototype.destination	❌
Request.prototype.headers	✅
Request.prototype.integrity	❌
Request.prototype.isHistoryNavigation	❌
Request.prototype.keepalive	❌
Request.prototype.method	✅	Normalize to lowercase
Request.prototype.mode	❌
Request.prototype.redirect	❌
Request.prototype.referrer	❌
Request.prototype.referrerPolicy	❌
Request.prototype.signal	✅
Request.prototype.url	✅
Request.prototype.arrayBuffer()	✅
Request.prototype.blob()	⚠️	Retuning GAS Blob
Request.prototype.bytes()	❌
Request.prototype.clone()	✅
Request.prototype.formData()	❌
Request.prototype.json()	✅
Request.prototype.text()	✅

Response

	Status	Remarks
Response() constructor	✅
Response.error()	✅	type is "error"
Response.json()	❌
Response.redirect()	✅
Response.prototype.body	❌	ReadableStream is not supported on GAS
Response.prototype.bodyUsed	✅
Response.prototype.headers	✅
Reponse.prototype.ok	✅
Response.prototype.redirected	✅
Response.prototype.status	✅
Response.prototype.statusText	✅
Response.prototype.type	⚠️	Always be "default"
Response.prototype.url	✅
Response.prototype.arrayBuffer()	✅
Response.prototype.blob()	⚠️	Retuning GAS Blob
Response.prototype.bytes()	❌
Response.prototype.clone()	✅
Response.prototype.formData()	❌
Response.prototype.json()	✅
Response.prototype.text()	✅

Headers

	Status	Remarks
Headers() constructor	✅
[Symbol.iterator]	✅
Headers.prototype.append()	✅
Headers.prototype.delete()	✅
Headers.prototype.entries()	✅
Headers.prototype.forEach()	✅
Headers.prototype.get()	✅
Headers.prototype.getSetCookie()	❌
Headers.prototype.has()	✅
Iteration combines duplicate header names	✅
Iteration is lexicographically sorted	❌
Headers.prototype.keys()	✅
Headers.prototype.set()	✅
Headers.prototype.values()	✅

URL

	Status	Remarks
URL() constructor	✅
URL.parse()	❌
URL.canParse()	❌
URL.createObjectURL()	❌
URL.revokeObjectURL()	❌
URL.prototype.hash	✅
URL.prototype.host	❌
URL.prototype.hostname	✅
URL.prototype.href	✅
URL.prototype.origin	✅
URL.prototype.password	✅
URL.prototype.pathname	✅
URL.prototype.port	✅
URL.prototype.protocol	✅
URL.prototype.search	✅
URL.prototype.searchParams	❌
URL.prototype.username	❌
URL.prototype.toJSON()	❌
URL.prototype.toString()	✅

URLSearchParams

	Status	Remarks
URLSearchParams() constructor	✅
URLSearchParams.prototype.size	❌
URLSearchParams.prototype.append()	✅
URLSearchParams.prototype.delete()	✅
URLSearchParams.prototype.entries()	✅
URLSearchParams.prototype.forEach()	✅
URLSearchParams.prototype.get()	✅
URLSearchParams.prototype.getAll()	✅
URLSearchParams.prototype.has()	✅
URLSearchParams.prototype.keys()	✅
URLSearchParams.prototype.set()	✅
URLSearchParams.prototype.sort()	❌
URLSearchParams.prototype.values()	✅
URLSearchParams.prototype.toString()	✅

AbortController AbortController and AbortSignal are implemented using the mysticatea/abort-controller.

	Status	Remarks
AbortController() constructor	✅
AbortController.prototype.signal	✅
AbortController.prototype.abort()	✅

AbortSignal

	Status	Remarks
AbortSignal.abort()	❌
AbortSignal.any()	❌
AbortSignal.timeout()	❌
AbortSignal.prototype.aborted	✅
AbortSignal.prototype.reason	❌
AbortSignal.prototype.onabort	✅
AbortSignal.prototype.addEventListener()	✅
AbortSignal.prototype.removeEventListener()	✅
AbortSignal.prototype.dispatchEvent()	✅
AbortSignal.prototype.throwIfAborted()	❌

License

MIT

src/fetch.ts is based on github/fetch and is licensed under MIT.

The bundled code includes abort-controller and event-target-shim. They are licensed under MIT.