feat: Add support for clear undo redo stack. (#106)

Add function clearing both undo a redo stack.
New test verifying undo-redo functionality.
Updated README.md.

Author: LukasSefcik

README.md

@@ -382,6 +382,7 @@ public class UndoRedoComponent {
 
   canUndo = this.store.canUndo; // use in template or in ts
   canRedo = this.store.canRedo; // use in template or in ts
+  clearStack = this.store.clearStack; // use in template or in ts
 
   undo(): void {
     if (!this.canUndo()) return;
@@ -392,6 +393,10 @@ public class UndoRedoComponent {
     if (!this.canRedo()) return;
     this.store.redo();
   }
+
+  clearStack(): void {
+    this.store.clearStack();
+  }
 }
 ```
 

libs/ngrx-toolkit/src/lib/with-undo-redo.spec.ts

@@ -21,7 +21,8 @@ describe('withUndoRedo', () => {
         'canUndo',
         'canRedo',
         'undo',
-        'redo'
+        'redo',
+        'clearStack'
       ]);
     });
   });
@@ -190,5 +191,24 @@ describe('withUndoRedo', () => {
         expect(store.canRedo()).toBe(true);
       });
     }));
+
+    it('clears undo redo stack', () => {
+      const Store = signalStore(
+        { providedIn: 'root' },
+        withState(testState),
+        withMethods(store => ({ update: (value: string) => patchState(store, { test: value }) })),
+        withUndoRedo({ keys: testKeys })
+      );
+
+      const store = TestBed.inject(Store);
+
+      store.update('Foo');
+      store.update('Bar');
+      store.undo();
+      store.clearStack();
+
+      expect(store.canUndo()).toBe(false);
+      expect(store.canRedo()).toBe(false);
+    })
   });
 });

libs/ngrx-toolkit/src/lib/with-undo-redo.ts

@@ -61,6 +61,7 @@ export function withUndoRedo<
   methods: {
     undo: () => void;
     redo: () => void;
+    clearStack: () => void;
   };
 }
 > {
@@ -126,6 +127,11 @@ export function withUndoRedo<
 
         updateInternal();
       },
+      clearStack(): void {
+        undoStack.splice(0);
+        redoStack.splice(0);
+        updateInternal();
+      },
     })),
     withHooks({
       onInit(store) {