From 89f64e58c30389f9896532bfb65bc4138fc19ed1 Mon Sep 17 00:00:00 2001
From: Zaven Muradyan <voithos@google.com>
Date: Thu, 8 Mar 2018 12:16:01 -0800
Subject: [PATCH] fix(router): avoid freezing queryParams in-place (#22663)

The recognizer code used to call Object.freeze() on queryParams before
using them to construct ActivatedRoutes, with the intent being to help
avoid common invalid usage. Unfortunately, Object.freeze() works
in-place, so this was also freezing the queryParams on the actual
UrlTree object, making it more difficult to manipulate UrlTrees in
things like UrlHandlingStrategy.

This change simply shallow-copies the queryParams before freezing them.

Fixes #22617

PR Close #22663
---
 packages/router/src/recognize.ts       | 9 +++++----
 packages/router/test/recognize.spec.ts | 8 ++++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/packages/router/src/recognize.ts b/packages/router/src/recognize.ts
index 74684f78b0..b6eeded31a 100644
--- a/packages/router/src/recognize.ts
+++ b/packages/router/src/recognize.ts
@@ -38,8 +38,9 @@ class Recognizer {
       const children = this.processSegmentGroup(this.config, rootSegmentGroup, PRIMARY_OUTLET);
 
       const root = new ActivatedRouteSnapshot(
-          [], Object.freeze({}), Object.freeze(this.urlTree.queryParams), this.urlTree.fragment !,
-          {}, PRIMARY_OUTLET, this.rootComponentType, null, this.urlTree.root, -1, {});
+          [], Object.freeze({}), Object.freeze({...this.urlTree.queryParams}),
+          this.urlTree.fragment !, {}, PRIMARY_OUTLET, this.rootComponentType, null,
+          this.urlTree.root, -1, {});
 
       const rootNode = new TreeNode<ActivatedRouteSnapshot>(root, children);
       const routeState = new RouterStateSnapshot(this.url, rootNode);
@@ -116,7 +117,7 @@ class Recognizer {
     if (route.path === '**') {
       const params = segments.length > 0 ? last(segments) !.parameters : {};
       snapshot = new ActivatedRouteSnapshot(
-          segments, params, Object.freeze(this.urlTree.queryParams), this.urlTree.fragment !,
+          segments, params, Object.freeze({...this.urlTree.queryParams}), this.urlTree.fragment !,
           getData(route), outlet, route.component !, route, getSourceSegmentGroup(rawSegment),
           getPathIndexShift(rawSegment) + segments.length, getResolve(route));
     } else {
@@ -125,7 +126,7 @@ class Recognizer {
       rawSlicedSegments = segments.slice(result.lastChild);
 
       snapshot = new ActivatedRouteSnapshot(
-          consumedSegments, result.parameters, Object.freeze(this.urlTree.queryParams),
+          consumedSegments, result.parameters, Object.freeze({...this.urlTree.queryParams}),
           this.urlTree.fragment !, getData(route), outlet, route.component !, route,
           getSourceSegmentGroup(rawSegment),
           getPathIndexShift(rawSegment) + consumedSegments.length, getResolve(route));
diff --git a/packages/router/test/recognize.spec.ts b/packages/router/test/recognize.spec.ts
index f224f0e0ab..1db36a1cd1 100644
--- a/packages/router/test/recognize.spec.ts
+++ b/packages/router/test/recognize.spec.ts
@@ -748,6 +748,14 @@ describe('recognize', () => {
         expect(Object.isFrozen(s.root.queryParams)).toBeTruthy();
       });
     });
+
+    it('should not freeze UrlTree query params', () => {
+      const url = tree('a?q=11');
+      recognize(RootComponent, [{path: 'a', component: ComponentA}], url, 'a?q=11')
+          .subscribe((s: RouterStateSnapshot) => {
+            expect(Object.isFrozen(url.queryParams)).toBe(false);
+          });
+    });
   });
 
   describe('fragment', () => {