From e69cb3639adc97d61fa878f454f22693093c98f6 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Sat, 27 Oct 2018 12:14:28 -0400
Subject: [PATCH] redirect to external URLs - closes #490

---
 .../src/server/middleware/get_page_handler.ts |  4 +-
 test/apps/AppRunner.ts                        | 14 ++++++
 test/apps/redirects/src/routes/index.html     |  3 +-
 .../src/routes/redirect-to-external.html      |  9 ++++
 test/apps/redirects/test.ts                   | 44 ++++++++++++++++---
 5 files changed, 66 insertions(+), 8 deletions(-)
 create mode 100644 test/apps/redirects/src/routes/redirect-to-external.html

diff --git a/templates/src/server/middleware/get_page_handler.ts b/templates/src/server/middleware/get_page_handler.ts
index c2049f2..78eb559 100644
--- a/templates/src/server/middleware/get_page_handler.ts
+++ b/templates/src/server/middleware/get_page_handler.ts
@@ -3,7 +3,7 @@ import * as path from 'path';
 import cookie from 'cookie';
 import devalue from 'devalue';
 import fetch from 'node-fetch';
-import { URL } from 'url';
+import { URL, resolve } from 'url';
 import { build_dir, dev, src_dir, IGNORE } from '../placeholders';
 import { Manifest, Page, Props, Req, Res, Store } from './types';
 
@@ -160,7 +160,7 @@ export function get_page_handler(
 
 		try {
 			if (redirect) {
-				const location = `${req.baseUrl}/${redirect.location}`;
+				const location = resolve(req.baseUrl || '/', redirect.location);
 
 				res.statusCode = redirect.statusCode;
 				res.setHeader('Location', location);
diff --git a/test/apps/AppRunner.ts b/test/apps/AppRunner.ts
index 077a3b7..0965329 100644
--- a/test/apps/AppRunner.ts
+++ b/test/apps/AppRunner.ts
@@ -50,6 +50,20 @@ export class AppRunner {
 			}
 		});
 
+		await this.page.setRequestInterception(true);
+
+		this.page.on('request', interceptedRequest => {
+			if (/example\.com/.test(interceptedRequest.url())) {
+				interceptedRequest.respond({
+					status: 200,
+					contentType: 'text/html',
+					body: `<h1>external</h1>`
+				});
+			} else {
+				interceptedRequest.continue();
+			}
+		});
+
 		return {
 			page: this.page,
 			base: `http://localhost:${this.port}`,
diff --git a/test/apps/redirects/src/routes/index.html b/test/apps/redirects/src/routes/index.html
index 6a94654..804a3dc 100644
--- a/test/apps/redirects/src/routes/index.html
+++ b/test/apps/redirects/src/routes/index.html
@@ -1,4 +1,5 @@
 <h1>root</h1>
 
 <a href="redirect-from">redirect from</a>
-<a href="redirect-to-root">redirect to root</a>
\ No newline at end of file
+<a href="redirect-to-root">redirect to root</a>
+<a href="redirect-to-external">redirect to external</a>
\ No newline at end of file
diff --git a/test/apps/redirects/src/routes/redirect-to-external.html b/test/apps/redirects/src/routes/redirect-to-external.html
new file mode 100644
index 0000000..fec2fee
--- /dev/null
+++ b/test/apps/redirects/src/routes/redirect-to-external.html
@@ -0,0 +1,9 @@
+<h1>unredirected</h1>
+
+<script>
+	export default {
+		preload() {
+			this.redirect(301, 'https://example.com');
+		}
+	};
+</script>
\ No newline at end of file
diff --git a/test/apps/redirects/test.ts b/test/apps/redirects/test.ts
index 8054924..719a92c 100644
--- a/test/apps/redirects/test.ts
+++ b/test/apps/redirects/test.ts
@@ -14,13 +14,14 @@ describe('redirects', function() {
 	// helpers
 	let start: () => Promise<void>;
 	let prefetchRoutes: () => Promise<void>;
+	let title: () => Promise<string>;
 
 	// hooks
 	before(async () => {
 		await build({ cwd: __dirname });
 
 		runner = new AppRunner(__dirname, '__sapper__/build/server/server.js');
-		({ base, page, start, prefetchRoutes } = await runner.start());
+		({ base, page, start, prefetchRoutes, title } = await runner.start());
 	});
 
 	after(() => runner.end());
@@ -34,7 +35,7 @@ describe('redirects', function() {
 		);
 
 		assert.equal(
-			await page.$eval('h1', node => node.textContent),
+			await title(),
 			'redirected'
 		);
 	});
@@ -53,7 +54,7 @@ describe('redirects', function() {
 		);
 
 		assert.equal(
-			await page.$eval('h1', node => node.textContent),
+			await title(),
 			'redirected'
 		);
 	});
@@ -67,7 +68,7 @@ describe('redirects', function() {
 		);
 
 		assert.equal(
-			await page.$eval('h1', node => node.textContent),
+			await title(),
 			'root'
 		);
 	});
@@ -86,8 +87,41 @@ describe('redirects', function() {
 		);
 
 		assert.equal(
-			await page.$eval('h1', node => node.textContent),
+			await title(),
 			'root'
 		);
 	});
+
+	it('redirects to external URL on server', async () => {
+		await page.goto(`${base}/redirect-to-external`);
+
+		assert.equal(
+			page.url(),
+			`https://example.com/`
+		);
+
+		assert.equal(
+			await title(),
+			'external'
+		);
+	});
+
+	it('redirects to external URL in client', async () => {
+		await page.goto(base);
+		await start();
+		await prefetchRoutes();
+
+		await page.click('[href="redirect-to-external"]');
+		await wait(50);
+
+		assert.equal(
+			page.url(),
+			`https://example.com/`
+		);
+
+		assert.equal(
+			await title(),
+			'external'
+		);
+	});
 });
\ No newline at end of file