From 38bce8845b881be33114606cf375662e1b4cce2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Maniecki?= <969645+P4@users.noreply.github.com>
Date: Mon, 28 Mar 2022 15:39:21 +0200
Subject: [PATCH] fix(component-store): memoization not working when passing
 selectors directly to select (#3356)

---
 .../spec/component-store.spec.ts               | 18 ++++++++++++++++++
 modules/component-store/src/component-store.ts |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/modules/component-store/spec/component-store.spec.ts b/modules/component-store/spec/component-store.spec.ts
index 8afdf66fd3..2aaa3f54e9 100644
--- a/modules/component-store/spec/component-store.spec.ts
+++ b/modules/component-store/spec/component-store.spec.ts
@@ -23,6 +23,7 @@ import {
   delay,
   concatMap,
 } from 'rxjs/operators';
+import { createSelector } from '@ngrx/store';
 
 describe('Component Store', () => {
   describe('initialization', () => {
@@ -895,6 +896,23 @@ describe('Component Store', () => {
 
       componentStore.ngOnDestroy();
     });
+
+    it('supports memoization with createSelector', () => {
+      const projectorCallback = jest.fn((str: string) => str);
+      const memoizedSelector = createSelector(
+        (s: State) => s.value,
+        projectorCallback
+      );
+      const selector = componentStore.select(memoizedSelector);
+
+      // first call to memoizedSelector
+      const subscription = selector.subscribe();
+      // second call to memoizedSelector with the same value
+      componentStore.setState(INIT_STATE);
+
+      subscription.unsubscribe();
+      expect(projectorCallback).toHaveBeenCalledTimes(1);
+    });
   });
 
   describe('selector with debounce', () => {
diff --git a/modules/component-store/src/component-store.ts b/modules/component-store/src/component-store.ts
index f606242657..a11bb689a6 100644
--- a/modules/component-store/src/component-store.ts
+++ b/modules/component-store/src/component-store.ts
@@ -244,7 +244,7 @@ export class ComponentStore<T extends object> implements OnDestroy {
     if (observables.length === 0) {
       observable$ = this.stateSubject$.pipe(
         config.debounce ? debounceSync() : (source$) => source$,
-        map(projector)
+        map((state) => projector(state))
       );
     } else {
       // If there are multiple arguments, then we're aggregating selectors, so we need