When using deferred updates, a sleeping pure computed should see pend…

…ing changes to its dependencies
knockout · Feb 13, 2017 · 7c1f400 · 7c1f400
1 parent 92f62a2
commit 7c1f400
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Showing 2 changed files with 20 additions and 2 deletions.
diff --git a/spec/asyncBehaviors.js b/spec/asyncBehaviors.js
@@ -989,7 +989,7 @@ describe('Deferred', function() {
         });
 
         it('Should *not* delay update of dependent deferred computed observable', function () {
-            var data = ko.observable('A'),
+            var data = ko.observable('A').extend({deferred:true}),
                 timesEvaluated = 0,
                 computed1 = ko.computed(function () { return data() + 'X'; }).extend({deferred:true}),
                 computed2 = ko.computed(function () { timesEvaluated++; return computed1() + 'Y'; }).extend({deferred:true}),
@@ -1010,6 +1010,24 @@ describe('Deferred', function() {
             expect(notifySpy.argsForCall).toEqual([ ['BXY'] ]);
         });
 
+        it('Should *not* delay update of dependent deferred pure computed observable', function () {
+            var data = ko.observable('A').extend({deferred:true}),
+                timesEvaluated = 0,
+                computed1 = ko.pureComputed(function () { return data() + 'X'; }).extend({deferred:true}),
+                computed2 = ko.pureComputed(function () { timesEvaluated++; return computed1() + 'Y'; }).extend({deferred:true});
+
+            expect(computed2()).toEqual('AXY');
+            expect(timesEvaluated).toEqual(1);
+
+            data('B');
+            expect(computed2()).toEqual('BXY');
+            expect(timesEvaluated).toEqual(2);
+
+            jasmine.Clock.tick(1);
+            expect(computed2()).toEqual('BXY');
+            expect(timesEvaluated).toEqual(2);      // Verify that the computed wasn't evaluated again unnecessarily
+        });
+
         it('Should *not* delay update of dependent rate-limited computed observable', function() {
             var data = ko.observable('A'),
                 deferredComputed = ko.computed(data).extend({deferred:true}),

diff --git a/src/subscribables/dependentObservable.js b/src/subscribables/dependentObservable.js
@@ -162,7 +162,7 @@ var computedFn = {
         for (id in dependencyTracking) {
             if (Object.prototype.hasOwnProperty.call(dependencyTracking, id)) {
                 dependency = dependencyTracking[id];
-                if (dependency._target.hasChanged(dependency._version)) {
+                if ((this._evalDelayed && dependency._target._notificationIsPending) || dependency._target.hasChanged(dependency._version)) {
                     return true;
                 }
             }