From b38931b48476bae751eae8905df139a7d170ca21 Mon Sep 17 00:00:00 2001
From: Victor Berchet <victor@suumit.com>
Date: Wed, 1 Aug 2018 10:57:16 -0700
Subject: [PATCH] fix(ivy): use devModeEqual in no change mode (#25252)

To avoid the unfamous error `Expression has changed after it was checked.`

PR Close #25252
---
 packages/core/src/render3/instructions.ts     |  2 +-
 packages/core/src/render3/util.ts             | 13 ++--
 .../bundling/todo/bundle.golden_symbols.json  |  2 +-
 packages/core/test/render3/util_spec.ts       | 63 ++++++++++++++-----
 4 files changed, 59 insertions(+), 21 deletions(-)

diff --git a/packages/core/src/render3/instructions.ts b/packages/core/src/render3/instructions.ts
index deb7709f29..f0b7be0af2 100644
--- a/packages/core/src/render3/instructions.ts
+++ b/packages/core/src/render3/instructions.ts
@@ -2739,7 +2739,7 @@ export function bindingUpdated(value: any): boolean {
 
   if (bindingIndex >= viewData.length) {
     viewData[viewData[BINDING_INDEX]++] = value;
-  } else if (isDifferent(viewData[bindingIndex], value)) {
+  } else if (isDifferent(viewData[bindingIndex], value, checkNoChangesMode)) {
     throwErrorIfNoChangesMode(creationMode, checkNoChangesMode, viewData[bindingIndex], value);
     viewData[viewData[BINDING_INDEX]++] = value;
   } else {
diff --git a/packages/core/src/render3/util.ts b/packages/core/src/render3/util.ts
index 22e73caeb2..784cc69dc4 100644
--- a/packages/core/src/render3/util.ts
+++ b/packages/core/src/render3/util.ts
@@ -5,15 +5,20 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
+import {devModeEqual} from '../change_detection/change_detection';
 import {assertLessThan} from './assert';
 import {LElementNode} from './interfaces/node';
 import {HEADER_OFFSET, LViewData} from './interfaces/view';
 
-
 /**
-* Must use this method for CD (instead of === ) since NaN !== NaN
-*/
-export function isDifferent(a: any, b: any): boolean {
+ * Returns wether the values are different from a change detection stand point.
+ *
+ * Constraints are relaxed in checkNoChanges mode. See `devModeEqual` for details.
+ */
+export function isDifferent(a: any, b: any, checkNoChangesMode: boolean): boolean {
+  if (ngDevMode && checkNoChangesMode) {
+    return !devModeEqual(a, b);
+  }
   // NaN is the only value that is not equal to itself so the first
   // test checks if both a and b are not NaN
   return !(a !== a && b !== b) && a !== b;
diff --git a/packages/core/test/bundling/todo/bundle.golden_symbols.json b/packages/core/test/bundling/todo/bundle.golden_symbols.json
index 757637d08b..70f606c52a 100644
--- a/packages/core/test/bundling/todo/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/todo/bundle.golden_symbols.json
@@ -9,7 +9,7 @@
     "name": "BLOOM_MASK"
   },
   {
-    "name": "CIRCULAR$1"
+    "name": "CIRCULAR$2"
   },
   {
     "name": "CLEANUP"
diff --git a/packages/core/test/render3/util_spec.ts b/packages/core/test/render3/util_spec.ts
index d591ff1267..02416e653d 100644
--- a/packages/core/test/render3/util_spec.ts
+++ b/packages/core/test/render3/util_spec.ts
@@ -12,25 +12,58 @@ describe('util', () => {
 
   describe('isDifferent', () => {
 
-    it('should mark non-equal arguments as different', () => {
-      expect(isDifferent({}, {})).toBeTruthy();
-      expect(isDifferent('foo', 'bar')).toBeTruthy();
-      expect(isDifferent(0, 1)).toBeTruthy();
+    describe('checkNoChangeMode = false', () => {
+      it('should mark non-equal arguments as different', () => {
+        expect(isDifferent({}, {}, false)).toBeTruthy();
+        expect(isDifferent('foo', 'bar', false)).toBeTruthy();
+        expect(isDifferent(0, 1, false)).toBeTruthy();
+      });
+
+      it('should not mark equal arguments as different', () => {
+        const obj = {};
+        expect(isDifferent(obj, obj, false)).toBeFalsy();
+        expect(isDifferent('foo', 'foo', false)).toBeFalsy();
+        expect(isDifferent(1, 1, false)).toBeFalsy();
+      });
+
+      it('should not mark NaN as different',
+         () => { expect(isDifferent(NaN, NaN, false)).toBeFalsy(); });
+
+      it('should mark NaN with other values as different', () => {
+        expect(isDifferent(NaN, 'foo', false)).toBeTruthy();
+        expect(isDifferent(5, NaN, false)).toBeTruthy();
+      });
     });
 
-    it('should not mark equal arguments as different', () => {
-      const obj = {};
-      expect(isDifferent(obj, obj)).toBeFalsy();
-      expect(isDifferent('foo', 'foo')).toBeFalsy();
-      expect(isDifferent(1, 1)).toBeFalsy();
+    describe('checkNoChangeMode = true', () => {
+      // Assert relaxed constraint in checkNoChangeMode
+      it('should not mark non-equal arrays, object and function as different', () => {
+        expect(isDifferent([], [], true)).toBeFalsy();
+        expect(isDifferent(() => 0, () => 0, true)).toBeFalsy();
+        expect(isDifferent({}, {}, true)).toBeFalsy();
+      });
+
+      it('should mark non-equal arguments as different', () => {
+        expect(isDifferent('foo', 'bar', true)).toBeTruthy();
+        expect(isDifferent(0, 1, true)).toBeTruthy();
+      });
+
+      it('should not mark equal arguments as different', () => {
+        const obj = {};
+        expect(isDifferent(obj, obj, false)).toBeFalsy();
+        expect(isDifferent('foo', 'foo', false)).toBeFalsy();
+        expect(isDifferent(1, 1, false)).toBeFalsy();
+      });
+
+      it('should not mark NaN as different',
+         () => { expect(isDifferent(NaN, NaN, false)).toBeFalsy(); });
+
+      it('should mark NaN with other values as different', () => {
+        expect(isDifferent(NaN, 'foo', false)).toBeTruthy();
+        expect(isDifferent(5, NaN, false)).toBeTruthy();
+      });
     });
 
-    it('should not mark NaN as different', () => { expect(isDifferent(NaN, NaN)).toBeFalsy(); });
-
-    it('should mark NaN with other values as different', () => {
-      expect(isDifferent(NaN, 'foo')).toBeTruthy();
-      expect(isDifferent(5, NaN)).toBeTruthy();
-    });
   });
 
   describe('flatten', () => {