From 439fb82d2a07cece417a18c47e37cfdeaaf38db7 Mon Sep 17 00:00:00 2001
From: Szymon Marczak <36894700+szmarczak@users.noreply.github.com>
Date: Mon, 2 Aug 2021 09:02:19 +0200
Subject: [PATCH] Fix relative URLs when paginating

---
 documentation/4-pagination.md |  4 +++-
 source/core/index.ts          |  4 ++--
 source/core/options.ts        | 12 +++++++++---
 source/core/response.ts       |  1 +
 test/pagination.ts            | 12 ++++++++++--
 5 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/documentation/4-pagination.md b/documentation/4-pagination.md
index b4b760fc7..32459bf32 100644
--- a/documentation/4-pagination.md
+++ b/documentation/4-pagination.md
@@ -87,7 +87,9 @@ console.log(results);
 		const next = parsed.find(entry => entry.parameters.rel === 'next' || entry.parameters.rel === '"next"');
 
 		if (next) {
-			return {url: next.reference};
+			return {
+				url: new URL(next.reference, response.requestUrl)
+			};
 		}
 
 		return false;
diff --git a/source/core/index.ts b/source/core/index.ts
index 64bc90a4b..806748543 100644
--- a/source/core/index.ts
+++ b/source/core/index.ts
@@ -1103,7 +1103,7 @@ export default class Request extends Duplex implements RequestEvents<Request> {
 		try {
 			// We can't do `await fn(...)`,
 			// because stream `error` event can be emitted before `Promise.resolve()`.
-			let requestOrResponse = fn(url, this._requestOptions);
+			let requestOrResponse = fn!(url, this._requestOptions);
 
 			if (is.promise(requestOrResponse)) {
 				requestOrResponse = await requestOrResponse;
@@ -1111,7 +1111,7 @@ export default class Request extends Duplex implements RequestEvents<Request> {
 
 			// Fallback
 			if (is.undefined(requestOrResponse)) {
-				requestOrResponse = options.getFallbackRequestFunction()(url, this._requestOptions);
+				requestOrResponse = options.getFallbackRequestFunction()!(url, this._requestOptions);
 
 				if (is.promise(requestOrResponse)) {
 					requestOrResponse = await requestOrResponse;
diff --git a/source/core/options.ts b/source/core/options.ts
index 6a9377b26..98a464185 100644
--- a/source/core/options.ts
+++ b/source/core/options.ts
@@ -691,7 +691,9 @@ const defaultInternals: Options['_internals'] = {
 			const next = parsed.find(entry => entry.parameters.rel === 'next' || entry.parameters.rel === '"next"');
 
 			if (next) {
-				return {url: next.reference};
+				return {
+					url: new URL(next.reference, response.requestUrl),
+				};
 			}
 
 			return false;
@@ -2224,13 +2226,17 @@ export default class Options {
 			return this.getFallbackRequestFunction();
 		}
 
-		return request!;
+		return request;
 	}
 
 	getFallbackRequestFunction() {
 		const url = this._internals.url as (URL | undefined);
 
-		if (url!.protocol === 'https:') {
+		if (!url) {
+			return;
+		}
+
+		if (url.protocol === 'https:') {
 			if (this._internals.http2) {
 				if (major < 15 || (major === 15 && minor < 10)) {
 					const error = new Error('To use the `http2` option, install Node.js 15.10.0 or above');
diff --git a/source/core/response.ts b/source/core/response.ts
index 314bf4775..a02ece88d 100644
--- a/source/core/response.ts
+++ b/source/core/response.ts
@@ -1,3 +1,4 @@
+import type {URL} from 'url';
 import type {IncomingMessageWithTimings, Timings} from '@szmarczak/http-timer';
 import {RequestError} from './errors.js';
 import type {ParseJsonFunction, ResponseType} from './options.js';
diff --git a/test/pagination.ts b/test/pagination.ts
index 78cd21c37..9fd4e6fdd 100644
--- a/test/pagination.ts
+++ b/test/pagination.ts
@@ -17,14 +17,14 @@ const resetPagination = {
 	shouldContinue: undefined,
 };
 
-const attachHandler = (server: ExtendedHttpTestServer, count: number): void => {
+const attachHandler = (server: ExtendedHttpTestServer, count: number, {relative} = {relative: false}): void => {
 	server.get('/', (request, response) => {
 		// eslint-disable-next-line unicorn/prevent-abbreviations
 		const searchParams = new URLSearchParams(request.url.split('?')[1]);
 		const page = Number(searchParams.get('page')) || 1;
 
 		if (page < count) {
-			response.setHeader('link', `<${server.url}/?page=${page + 1}>; rel="next"`);
+			response.setHeader('link', `<${relative ? '' : server.url}/?page=${page + 1}>; rel="next"`);
 		}
 
 		response.end(`[${page <= count ? page : ''}]`);
@@ -720,6 +720,14 @@ test('calls init hooks on pagination', withServer, async (t, server) => {
 	]);
 });
 
+test('retrieves all elements - relative url', withServer, async (t, server, got) => {
+	attachHandler(server, 2, {relative: true});
+
+	const result = await got.paginate.all<number>('');
+
+	t.deepEqual(result, [1, 2]);
+});
+
 test('throws when transform does not return an array', withServer, async (t, server) => {
 	server.get('/', (_request, response) => {
 		response.end(JSON.stringify(''));