fix: encode redirect url if not already encoded (#1384)

Same bug from express expressjs/express@76eaa32

Author: fengmk2

Diff for: lib/response.js

@@ -19,6 +19,7 @@ const extname = require('path').extname;
 const vary = require('vary');
 const only = require('only');
 const util = require('util');
+const encodeUrl = require('encodeurl');
 
 /**
  * Prototype.
@@ -260,7 +261,7 @@ module.exports = {
   redirect(url, alt) {
     // location
     if ('back' == url) url = this.ctx.get('Referrer') || alt || '/';
-    this.set('Location', url);
+    this.set('Location', encodeUrl(url));
 
     // status
     if (!statuses.redirect[this.status]) this.status = 302;

Diff for: package.json

@@ -31,6 +31,7 @@
     "delegates": "^1.0.0",
     "depd": "^1.1.2",
     "destroy": "^1.0.4",
+    "encodeurl": "^1.0.2",
     "error-inject": "^1.0.0",
     "escape-html": "^1.0.3",
     "fresh": "~0.5.2",

Diff for: test/response/redirect.js

@@ -2,7 +2,9 @@
 'use strict';
 
 const assert = require('assert');
+const request = require('supertest');
 const context = require('../helpers/context');
+const Koa = require('../..');
 
 describe('ctx.redirect(url)', () => {
   it('should redirect to the given url', () => {
@@ -12,6 +14,23 @@ describe('ctx.redirect(url)', () => {
     assert.equal(ctx.status, 302);
   });
 
+  it('should auto fix not encode url', done => {
+    const app = new Koa();
+
+    app.use(ctx => {
+      ctx.redirect('http://google.com/😓');
+    });
+
+    request(app.callback())
+      .get('/')
+      .end((err, res) => {
+        if (err) return done(err);
+        assert.equal(res.status, 302);
+        assert.equal(res.headers.location, 'http://google.com/%F0%9F%98%93');
+        done();
+      });
+  });
+
   describe('with "back"', () => {
     it('should redirect to Referrer', () => {
       const ctx = context();