feat(query): 🔥 add injectIsMutating

Author: luii

query/src/lib/is-mutating.ts

@@ -0,0 +1,38 @@
+import {
+  type MutationFilters,
+  notifyManager
+} from '@tanstack/query-core';
+import { injectQueryClient } from './query-client';
+import { inject, Injectable, InjectionToken } from '@angular/core';
+import { distinctUntilChanged, Observable } from 'rxjs';
+
+@Injectable({ providedIn: 'root' })
+export class IsMutatingService {
+  private queryClient = injectQueryClient();
+
+  use(filters?: MutationFilters) {
+    return new Observable<number>((observer) => {
+      observer.next(this.queryClient.isMutating(filters));
+      this.queryClient.getMutationCache().subscribe(
+        notifyManager.batchCalls(() => {
+          observer.next(this.queryClient.isMutating(filters));
+        })
+      );
+    }).pipe(distinctUntilChanged());
+  }
+}
+
+const UseIsMutating = new InjectionToken<IsMutatingService['use']>(
+  'UseIsFetching',
+  {
+    providedIn: 'root',
+    factory() {
+      const isMutating = new IsMutatingService();
+      return isMutating.use.bind(isMutating);
+    },
+  }
+);
+
+export function injectIsMutating() {
+  return inject(UseIsMutating);
+}