From 89b7c02b4ae7fb6797767292870f99a6320e018d Mon Sep 17 00:00:00 2001
From: Adam Pancutt <adam@pancutt.com>
Date: Mon, 2 Nov 2020 14:51:55 +0100
Subject: [PATCH] Allow router.redirect() to accept external destinations
 (#110)

* Allow router.redirect() to accept external destinations

* Remove redundant case-insensitive flag

* Added tests for router.redirect() with external destinations

* Simplify external destination detection
---
 lib/router.js      |  2 +-
 test/lib/router.js | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/lib/router.js b/lib/router.js
index 4c27578..a7f0871 100644
--- a/lib/router.js
+++ b/lib/router.js
@@ -532,7 +532,7 @@ Router.prototype.redirect = function (source, destination, code) {
   if (source[0] !== '/') source = this.url(source);
 
   // lookup destination route by name
-  if (destination[0] !== '/') destination = this.url(destination);
+  if (destination[0] !== '/' && !destination.includes('://')) destination = this.url(destination);
 
   return this.all(source, ctx => {
     ctx.redirect(destination);
diff --git a/test/lib/router.js b/test/lib/router.js
index 71c601a..1344f52 100644
--- a/test/lib/router.js
+++ b/test/lib/router.js
@@ -1305,6 +1305,36 @@ describe('Router', function () {
           done();
         });
     });
+
+    it('redirects to external sites', function (done) {
+      const app = new Koa();
+      const router = new Router();
+      app.use(router.routes());
+      router.redirect('/', 'https://www.example.com');
+      request(http.createServer(app.callback()))
+        .post('/')
+        .expect(301)
+        .end(function (err, res) {
+          if (err) return done(err);
+          res.header.should.have.property('location', 'https://www.example.com');
+          done();
+        });
+    });
+
+    it('redirects to any external protocol', function (done) {
+      const app = new Koa();
+      const router = new Router();
+      app.use(router.routes());
+      router.redirect('/', 'my-custom-app-protocol://www.example.com/foo');
+      request(http.createServer(app.callback()))
+        .post('/')
+        .expect(301)
+        .end(function (err, res) {
+          if (err) return done(err);
+          res.header.should.have.property('location', 'my-custom-app-protocol://www.example.com/foo');
+          done();
+        });
+    });
   });
 
   describe('Router#route()', function () {