From b7ea609d1b534846cdc5bcdd1eaef149167e77e7 Mon Sep 17 00:00:00 2001
From: atharvasingh7007 <singhatharva7007@gmail.com>
Date: Thu, 16 Apr 2026 12:52:04 +0530
Subject: [PATCH] fix: isolate tuple searchParams in init hooks

---
 source/core/Ky.ts | 10 +++++++++-
 test/hooks.ts     | 30 ++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/source/core/Ky.ts b/source/core/Ky.ts
index 5e8c8f57..2ede2a7a 100644
--- a/source/core/Ky.ts
+++ b/source/core/Ky.ts
@@ -84,6 +84,14 @@ const isRequestInstance = (value: unknown): value is Request =>
 const isResponseInstance = (value: unknown): value is Response =>
 	value instanceof globalThis.Response || objectToString.call(value) === '[object Response]';
 
+const cloneSearchParametersForInitHook = (searchParameters: SearchParamsOption | undefined): SearchParamsOption | undefined => {
+	if (Array.isArray(searchParameters)) {
+		return searchParameters.map(parameter => [...parameter]) as SearchParamsOption;
+	}
+
+	return cloneShallow(searchParameters) as SearchParamsOption | undefined;
+};
+
 // Shallow-clone mutable option properties so init hook mutations don't leak across requests.
 function cloneInitHookOptions(options: Options): Options {
 	const clonedOptions: Options = {
@@ -91,7 +99,7 @@ function cloneInitHookOptions(options: Options): Options {
 		json: cloneShallow(options.json),
 		context: cloneShallow(options.context)!,
 		headers: cloneShallow(options.headers)!,
-		searchParams: cloneShallow(options.searchParams) as SearchParamsOption | undefined,
+		searchParams: cloneSearchParametersForInitHook(options.searchParams),
 	};
 
 	if (options.retry !== undefined) {
diff --git a/test/hooks.ts b/test/hooks.ts
index 5059c096..66e6f444 100644
--- a/test/hooks.ts
+++ b/test/hooks.ts
@@ -4900,6 +4900,36 @@ test('init hook in-place mutations do not leak across requests', async t => {
 	t.deepEqual(seenRequestIdentifiers, ['1', '2']);
 });
 
+test('init hook tuple searchParams mutations do not leak across requests', async t => {
+	let requestIdentifier = 0;
+	const seenInitialValues: string[] = [];
+	const seenRequestIdentifiers: string[] = [];
+
+	const api = ky.extend({
+		searchParams: [['requestId', 'seed']],
+		hooks: {
+			init: [
+				options => {
+					const searchParameters = options.searchParams as string[][];
+					seenInitialValues.push(searchParameters[0]![1]!);
+					searchParameters[0]![1] = String(++requestIdentifier);
+				},
+			],
+		},
+	});
+
+	const fetch: typeof globalThis.fetch = async request => {
+		seenRequestIdentifiers.push(new URL(request.url).searchParams.get('requestId')!);
+		return new Response('ok');
+	};
+
+	await api.get('https://example.com', {fetch});
+	await api.get('https://example.com', {fetch});
+
+	t.deepEqual(seenInitialValues, ['seed', 'seed']);
+	t.deepEqual(seenRequestIdentifiers, ['1', '2']);
+});
+
 test('init hook in-place retry mutations do not leak across requests', async t => {
 	const seenLimits: number[] = [];