Make URLSearchParams mergeable (#734)

readme.md

@@ -726,6 +726,7 @@ got.mergeOptions(a, b)  // => {headers: {cat: 'meow', cow: 'moo', wolf: ['auuu']
 Options are deeply merged to a new object. The value of each key is determined as follows:
 
 - If the new property is set to `undefined`, it keeps the old one.
+- If both properties are an instances of `URLSearchParams`, a new URLSearchParams instance is created. The values are merged using [`urlSearchParams.append(key, value)`](https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams/append).
 - If the parent property is an instance of `URL` and the new value is a `string` or `URL`, a new URL instance is created: [`new URL(new, parent)`](https://developer.mozilla.org/en-US/docs/Web/API/URL/URL#Syntax).
 - If the new property is a plain `Object`:
 	- If the parent property is a plain `Object` too, both values are merged recursively into a new `Object`.

source/merge.ts

@@ -1,4 +1,4 @@
-import {URL} from 'url';
+import {URL, URLSearchParams} from 'url';
 import is from '@sindresorhus/is';
 import {Options, Method, NextFunction, Instance, InterfaceWithDefaults} from './utils/types';
 import knownHookEvents, {Hooks, HookType, HookEvent} from './known-hook-events';
@@ -11,7 +11,15 @@ export default function merge<Target extends {[key: string]: unknown}, Source ex
 			}
 
 			const targetValue = target[key];
-			if (is.urlInstance(targetValue) && (is.urlInstance(sourceValue) || is.string(sourceValue))) {
+			if (targetValue instanceof URLSearchParams && sourceValue instanceof URLSearchParams) {
+				const params = new URLSearchParams();
+
+				const append = (value: string, key: string) => params.append(key, value);
+				targetValue.forEach(append);
+				sourceValue.forEach(append);
+
+				target[key] = params;
+			} else if (is.urlInstance(targetValue) && (is.urlInstance(sourceValue) || is.string(sourceValue))) {
 				target[key] = new URL(sourceValue as string, targetValue);
 			} else if (is.plainObject(sourceValue)) {
 				if (is.plainObject(targetValue)) {

source/normalize-arguments.js

@@ -60,10 +60,11 @@ const preNormalize = (options, defaults) => {
 
 	const {retry} = options;
 	options.retry = {
-		retries: 0,
-		methods: [],
-		statusCodes: [],
-		errorCodes: []
+		retries: () => 0,
+		methods: new Set(),
+		statusCodes: new Set(),
+		errorCodes: new Set(),
+		maxRetryAfter: undefined
 	};
 
 	if (is.nonEmptyObject(defaults) && retry !== false) {
@@ -78,7 +79,7 @@ const preNormalize = (options, defaults) => {
 		}
 	}
 
-	if (options.gotTimeout) {
+	if (!options.retry.maxRetryAfter && options.gotTimeout) {
 		options.retry.maxRetryAfter = Math.min(...[options.gotTimeout.request, options.gotTimeout.connection].filter(n => !is.nullOrUndefined(n)));
 	}
 
@@ -153,7 +154,9 @@ const normalize = (url, options, defaults) => {
 		get: () => baseUrl
 	});
 
-	let searchParams;
+	let {searchParams} = options;
+	delete options.searchParams;
+
 	if (options.query) {
 		if (!shownDeprecation) {
 			console.warn('`options.query` is deprecated. We support it solely for compatibility - it will be removed in Got 11. Use `options.searchParams` instead.');
@@ -162,9 +165,6 @@ const normalize = (url, options, defaults) => {
 
 		searchParams = options.query;
 		delete options.query;
-	} else if (options.searchParams) {
-		searchParams = options.searchParams;
-		delete options.searchParams;
 	}
 
 	if (is.nonEmptyString(searchParams) || is.nonEmptyObject(searchParams) || searchParams instanceof URLSearchParams) {

test/merge-instances.js

@@ -1,3 +1,4 @@
+import {URLSearchParams} from 'url';
 import test from 'ava';
 import got from '../source';
 import {createServer} from './helpers/server';
@@ -134,3 +135,17 @@ test('hooks are passed by though other instances don\'t have them', t => {
 	const merged = got.mergeInstances(instanceA, instanceB, instanceC);
 	t.deepEqual(merged.defaults.options.hooks.beforeRequest, instanceA.defaults.options.hooks.beforeRequest);
 });
+
+test('URLSearchParams instances are merged', t => {
+	const instanceA = got.extend({
+		searchParams: new URLSearchParams({a: '1'})
+	});
+
+	const instanceB = got.extend({
+		searchParams: new URLSearchParams({b: '2'})
+	});
+
+	const merged = got.mergeInstances(instanceA, instanceB);
+	t.is(merged.defaults.options.searchParams.get('a'), '1');
+	t.is(merged.defaults.options.searchParams.get('b'), '2');
+});