Fix support with environments that add support for custom fetch opt…

…ions (#536)

source/core/Ky.ts

@@ -8,6 +8,7 @@ import {normalizeRequestMethod, normalizeRetryOptions} from '../utils/normalize.
 import timeout, {type TimeoutOptions} from '../utils/timeout.js';
 import delay from '../utils/delay.js';
 import {type ObjectEntries} from '../utils/types.js';
+import {findUnknownOptions} from '../utils/options.js';
 import {
 	maxSafeTimeout,
 	responseTypes,
@@ -294,11 +295,13 @@ export class Ky {
 			}
 		}
 
+		const nonRequestOptions = findUnknownOptions(this.request, this._options);
+
 		if (this._options.timeout === false) {
-			return this._options.fetch(this.request.clone());
+			return this._options.fetch(this.request.clone(), nonRequestOptions);
 		}
 
-		return timeout(this.request.clone(), this.abortController, this._options as TimeoutOptions);
+		return timeout(this.request.clone(), nonRequestOptions, this.abortController, this._options as TimeoutOptions);
 	}
 
 	/* istanbul ignore next */

source/core/constants.ts

@@ -1,5 +1,5 @@
 import type {Expect, Equal} from '@type-challenges/utils';
-import {type HttpMethod} from '../types/options.js';
+import {type HttpMethod, type KyOptionsRegistry} from '../types/options.js';
 
 export const supportsRequestStreams = (() => {
 	let duplexAccessed = false;
@@ -45,3 +45,16 @@ export const responseTypes = {
 export const maxSafeTimeout = 2_147_483_647;
 
 export const stop = Symbol('stop');
+
+export const kyOptionKeys: KyOptionsRegistry = {
+	json: true,
+	parseJson: true,
+	searchParams: true,
+	prefixUrl: true,
+	retry: true,
+	timeout: true,
+	hooks: true,
+	throwHttpErrors: true,
+	onDownloadProgress: true,
+	fetch: true,
+};

source/types/options.ts

@@ -25,53 +25,10 @@ export type DownloadProgress = {
 export type KyHeadersInit = HeadersInit | Record<string, string | undefined>;
 
 /**
-Options are the same as `window.fetch`, with some exceptions.
+Custom Ky options
 */
-export interface Options extends Omit<RequestInit, 'headers'> { // eslint-disable-line @typescript-eslint/consistent-type-definitions -- This must stay an interface so that it can be extended outside of Ky for use in `ky.create`.
-	/**
-	HTTP method used to make the request.
-
-	Internally, the standard methods (`GET`, `POST`, `PUT`, `PATCH`, `HEAD` and `DELETE`) are uppercased in order to avoid server errors due to case sensitivity.
-	*/
-	method?: LiteralUnion<HttpMethod, string>;
-
-	/**
-	HTTP headers used to make the request.
-
-	You can pass a `Headers` instance or a plain object.
-
-	You can remove a header with `.extend()` by passing the header with an `undefined` value.
-
-	@example
-	```
-	import ky from 'ky';
-
-	const url = 'https://sindresorhus.com';
-
-	const original = ky.create({
-		headers: {
-			rainbow: 'rainbow',
-			unicorn: 'unicorn'
-		}
-	});
-
-	const extended = original.extend({
-		headers: {
-			rainbow: undefined
-		}
-	});
-
-	const response = await extended(url).json();
-
-	console.log('rainbow' in response);
-	//=> false
-
-	console.log('unicorn' in response);
-	//=> true
-	```
-	*/
-	headers?: KyHeadersInit;
 
+export type KyOptions = {
 	/**
 	Shortcut for sending JSON. Use this instead of the `body` option.
 
@@ -221,6 +178,62 @@ export interface Options extends Omit<RequestInit, 'headers'> { // eslint-disabl
 	```
 	*/
 	fetch?: (input: RequestInfo, init?: RequestInit) => Promise<Response>;
+};
+
+/**
+Each key from KyOptions is present and set to `true`.
+
+This type is used for identifying and working with the known keys in KyOptions.
+*/
+export type KyOptionsRegistry = {[K in keyof KyOptions]-?: true};
+
+/**
+Options are the same as `window.fetch`, except for the KyOptions
+*/
+export interface Options extends KyOptions, Omit<RequestInit, 'headers'> { // eslint-disable-line @typescript-eslint/consistent-type-definitions -- This must stay an interface so that it can be extended outside of Ky for use in `ky.create`.
+	/**
+	HTTP method used to make the request.
+
+	Internally, the standard methods (`GET`, `POST`, `PUT`, `PATCH`, `HEAD` and `DELETE`) are uppercased in order to avoid server errors due to case sensitivity.
+	*/
+	method?: LiteralUnion<HttpMethod, string>;
+
+	/**
+	HTTP headers used to make the request.
+
+	You can pass a `Headers` instance or a plain object.
+
+	You can remove a header with `.extend()` by passing the header with an `undefined` value.
+
+	@example
+	```
+	import ky from 'ky';
+
+	const url = 'https://sindresorhus.com';
+
+	const original = ky.create({
+		headers: {
+			rainbow: 'rainbow',
+			unicorn: 'unicorn'
+		}
+	});
+
+	const extended = original.extend({
+		headers: {
+			rainbow: undefined
+		}
+	});
+
+	const response = await extended(url).json();
+
+	console.log('rainbow' in response);
+	//=> false
+
+	console.log('unicorn' in response);
+	//=> true
+	```
+	*/
+	headers?: KyHeadersInit;
 }
 
 export type InternalOptions = Required<

source/utils/options.ts

@@ -0,0 +1,16 @@
+import {kyOptionKeys} from '../core/constants.js';
+
+export const findUnknownOptions = (
+	request: Request,
+	options: Record<string, unknown>,
+): Record<string, unknown> => {
+	const unknownOptions: Record<string, unknown> = {};
+
+	for (const key in options) {
+		if (!(key in kyOptionKeys) && !(key in request)) {
+			unknownOptions[key] = options[key];
+		}
+	}
+
+	return unknownOptions;
+};

source/utils/timeout.ts

@@ -8,6 +8,7 @@ export type TimeoutOptions = {
 // `Promise.race()` workaround (#91)
 export default async function timeout(
 	request: Request,
+	init: RequestInit,
 	abortController: AbortController | undefined,
 	options: TimeoutOptions,
 ): Promise<Response> {
@@ -21,7 +22,7 @@ export default async function timeout(
 		}, options.timeout);
 
 		void options
-			.fetch(request)
+			.fetch(request, init)
 			.then(resolve)
 			.catch(reject)
 			.then(() => {

test/fetch.ts

@@ -64,3 +64,16 @@ test('options are correctly passed to Fetch #2', async t => {
 	const json = await ky.post('https://httpbin.org/anything', {json: fixture}).json();
 	t.deepEqual(json.json, fixture);
 });
+
+test('unknown options are passed to fetch', async t => {
+	t.plan(1);
+
+	const options = {next: {revalidate: 3600}};
+
+	const customFetch: typeof fetch = async (request, init) => {
+		t.is(init.next, options.next);
+		return new Response(request.url);
+	};
+
+	await ky(fixture, {...options, fetch: customFetch}).text();
+});