From 48f5027591b8a6379bd157aee9bf7910067fc7b0 Mon Sep 17 00:00:00 2001
From: "byron.stange" <byron.stange@pixell.de>
Date: Wed, 2 Aug 2017 13:13:45 +0200
Subject: [PATCH 1/2] fix(createSelector): Memoize projector fn

---
 modules/store/spec/selector.spec.ts | 18 ++++++++++++++++++
 modules/store/src/selector.ts       | 13 +++++++++----
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/modules/store/spec/selector.spec.ts b/modules/store/spec/selector.spec.ts
index d2db3ddb8c..0d721a9ac5 100644
--- a/modules/store/spec/selector.spec.ts
+++ b/modules/store/spec/selector.spec.ts
@@ -41,6 +41,24 @@ describe('Selectors', () => {
       expect(projectFn).toHaveBeenCalledWith(countOne, countTwo);
     });
 
+    it('should call the projector function only when the value of a dependent selector change', () => {
+      const firstState = { first: 'state', unchanged: 'state' };
+      const secondState = { second: 'state', unchanged: 'state' };
+      const neverChangingSelector = jasmine.createSpy('unchangedSelector').and.callFake((state: any) => {
+        return state.unchanged;
+      });
+      const projectFn = jasmine.createSpy('projectionFn');
+      const selector = createSelector(
+        neverChangingSelector,
+        projectFn
+      );
+
+      selector(firstState);
+      selector(secondState);
+
+      expect(projectFn).toHaveBeenCalledTimes(1);
+    });
+
     it('should memoize the function', () => {
       const firstState = { first: 'state' };
       const secondState = { second: 'state' };
diff --git a/modules/store/src/selector.ts b/modules/store/src/selector.ts
index 00c34f84c9..2a20df84ad 100644
--- a/modules/store/src/selector.ts
+++ b/modules/store/src/selector.ts
@@ -115,19 +115,24 @@ export function createSelector(...args: any[]): Selector<any, any> {
       selector.release && typeof selector.release === 'function'
   );
 
-  const { memoized, reset } = memoize(function(state: any) {
+  const memoizedProjector = memoize(function(...selectors: any[]) {
+    return projector.apply(null, selectors);
+  });
+
+  const memoizedState = memoize(function(state: any) {
     const args = selectors.map(fn => fn(state));
 
-    return projector.apply(null, args);
+    return memoizedProjector.memoized.apply(null, args);
   });
 
   function release() {
-    reset();
+    memoizedState.reset();
+    memoizedProjector.reset();
 
     memoizedSelectors.forEach(selector => selector.release());
   }
 
-  return Object.assign(memoized, { release });
+  return Object.assign(memoizedState.memoized, { release });
 }
 
 export function createFeatureSelector<T>(

From c91fe935f45a9d98039477820cabb54259854e55 Mon Sep 17 00:00:00 2001
From: "byron.stange" <byron.stange@pixell.de>
Date: Wed, 2 Aug 2017 13:18:53 +0200
Subject: [PATCH 2/2] fix(createSelector): Memoize projector fn

---
 modules/store/spec/selector.spec.ts | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/modules/store/spec/selector.spec.ts b/modules/store/spec/selector.spec.ts
index 0d721a9ac5..ac563fdabe 100644
--- a/modules/store/spec/selector.spec.ts
+++ b/modules/store/spec/selector.spec.ts
@@ -44,14 +44,13 @@ describe('Selectors', () => {
     it('should call the projector function only when the value of a dependent selector change', () => {
       const firstState = { first: 'state', unchanged: 'state' };
       const secondState = { second: 'state', unchanged: 'state' };
-      const neverChangingSelector = jasmine.createSpy('unchangedSelector').and.callFake((state: any) => {
-        return state.unchanged;
-      });
+      const neverChangingSelector = jasmine
+        .createSpy('unchangedSelector')
+        .and.callFake((state: any) => {
+          return state.unchanged;
+        });
       const projectFn = jasmine.createSpy('projectionFn');
-      const selector = createSelector(
-        neverChangingSelector,
-        projectFn
-      );
+      const selector = createSelector(neverChangingSelector, projectFn);
 
       selector(firstState);
       selector(secondState);