From dba4769fd7f2709ef1413dadfeab42ba1644b838 Mon Sep 17 00:00:00 2001
From: Michael Small <michaelsmalldev@gmail.com>
Date: Tue, 24 Feb 2026 21:31:49 -0600
Subject: [PATCH 1/3] fix: assign properties of mutations in withMutation

---
 libs/ngrx-toolkit/src/lib/with-mutations.ts | 27 +++++++++++++++------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/libs/ngrx-toolkit/src/lib/with-mutations.ts b/libs/ngrx-toolkit/src/lib/with-mutations.ts
index 5922307a..8586c1c5 100644
--- a/libs/ngrx-toolkit/src/lib/with-mutations.ts
+++ b/libs/ngrx-toolkit/src/lib/with-mutations.ts
@@ -118,14 +118,25 @@ function createMutationsFeature<Result extends MutationsDictionary>(
       keys.reduce(
         (acc, key) => ({
           ...acc,
-          [key]: async (params: never) => {
-            const mutation = mutations[key];
-            if (!mutation) {
-              throw new Error(`Mutation ${key} not found`);
-            }
-            const result = await mutation(params);
-            return result;
-          },
+          [key]: Object.assign(
+            async (params: never) => {
+              const mutation = mutations[key];
+              if (!mutation) {
+                throw new Error(`Mutation ${key} not found`);
+              }
+              const result = await mutation(params);
+
+              return result;
+            },
+            {
+              status: mutations[key].status,
+              value: mutations[key].value,
+              isPending: mutations[key].isPending,
+              isSuccess: mutations[key].isSuccess,
+              error: mutations[key].error,
+              hasValue: mutations[key].hasValue,
+            },
+          ),
         }),
         {} as MethodsDictionary,
       ),

From 7546899881fc3b47847492bdcfc3f77f8faefd01 Mon Sep 17 00:00:00 2001
From: Michael Small <michaelsmalldev@gmail.com>
Date: Sun, 10 May 2026 11:04:42 -0500
Subject: [PATCH 2/3] fix: reassign mutation whole, rather than subset of props

---
 libs/ngrx-toolkit/src/lib/with-mutations.ts | 25 ++++++++-------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/libs/ngrx-toolkit/src/lib/with-mutations.ts b/libs/ngrx-toolkit/src/lib/with-mutations.ts
index 8586c1c5..7cb142b0 100644
--- a/libs/ngrx-toolkit/src/lib/with-mutations.ts
+++ b/libs/ngrx-toolkit/src/lib/with-mutations.ts
@@ -118,25 +118,18 @@ function createMutationsFeature<Result extends MutationsDictionary>(
       keys.reduce(
         (acc, key) => ({
           ...acc,
-          [key]: Object.assign(
-            async (params: never) => {
-              const mutation = mutations[key];
-              if (!mutation) {
-                throw new Error(`Mutation ${key} not found`);
-              }
+          [key]: (() => {
+            const mutation = mutations[key];
+            if (!mutation) {
+              throw new Error(`Mutation ${key} not found`);
+            }
+
+            return Object.assign(async (params: never) => {
               const result = await mutation(params);
 
               return result;
-            },
-            {
-              status: mutations[key].status,
-              value: mutations[key].value,
-              isPending: mutations[key].isPending,
-              isSuccess: mutations[key].isSuccess,
-              error: mutations[key].error,
-              hasValue: mutations[key].hasValue,
-            },
-          ),
+            }, mutation);
+          })(),
         }),
         {} as MethodsDictionary,
       ),

From 1056989c0fc053d44291317e2bf40ca236f62caa Mon Sep 17 00:00:00 2001
From: Michael Small <michaelsmalldev@gmail.com>
Date: Tue, 12 May 2026 21:43:50 -0500
Subject: [PATCH 3/3] chore: add test for mutations property assignment

---
 .../src/lib/with-mutations.spec.ts            | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/libs/ngrx-toolkit/src/lib/with-mutations.spec.ts b/libs/ngrx-toolkit/src/lib/with-mutations.spec.ts
index 5bb3a80d..7faff07f 100644
--- a/libs/ngrx-toolkit/src/lib/with-mutations.spec.ts
+++ b/libs/ngrx-toolkit/src/lib/with-mutations.spec.ts
@@ -116,6 +116,31 @@ function createTestSetup(flatteningOperator = concatOp) {
 }
 
 describe('withMutations with rxMutation', () => {
+  // fix: assign properties of mutations in withMutation https://github.com/angular-architects/ngrx-toolkit/pull/288
+  it("does not lose the runtime properties of a mutation's direct reference when assigning it to a component field", fakeAsync(() => {
+    const testSetup = createTestSetup();
+    const store = testSetup.store;
+
+    // Simulates `readonly myMutation = this.store.increment` in a component.
+    const myMutation = store.increment;
+
+    expect(myMutation.status()).toEqual('idle');
+    expect(typeof myMutation.isPending).toEqual('function');
+    expect(myMutation.isPending()).toEqual(false);
+
+    myMutation(2);
+    expect(myMutation.status()).toEqual('pending');
+    expect(myMutation.isPending()).toEqual(true);
+
+    tick(2000);
+
+    expect(myMutation.status()).toEqual('success');
+    expect(myMutation.isPending()).toEqual(false);
+    expect(myMutation.error()).toEqual(undefined);
+
+    expect(store.counter()).toEqual(7);
+  }));
+
   it('should update the state', fakeAsync(() => {
     const testSetup = createTestSetup();
     const store = testSetup.store;