[Security Solution][Detection Engine] fixes apply alert tags issue (e…

…lastic#194428)

## Summary

- fixes elastic#192084

### Checklist

Delete any items that are not applicable to this PR.

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

x-pack/plugins/security_solution/public/common/components/toolbar/bulk_actions/reducer.test.ts

@@ -0,0 +1,53 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { State } from './reducer';
+import { createAlertTagsReducer } from './reducer';
+
+const initialState: State = {
+  selectableAlertTags: [],
+  tagsToAdd: new Set<string>(['False positive']),
+  tagsToRemove: new Set<string>(['Duplicate']),
+};
+
+describe('createAlertTagsReducer', () => {
+  it('should update state on addAlertTag action', () => {
+    const reducer = createAlertTagsReducer();
+    const state = reducer(initialState, { type: 'addAlertTag', value: 'Duplicate' });
+
+    expect(Array.from(state.tagsToAdd)).toEqual(['False positive', 'Duplicate']);
+    expect(Array.from(state.tagsToRemove)).toEqual([]);
+
+    // reducer action must not mutate previous state
+    expect(state.tagsToAdd).not.toBe(initialState.tagsToAdd);
+    expect(state.tagsToRemove).not.toBe(initialState.tagsToRemove);
+    expect(state).not.toBe(initialState);
+  });
+  it('should update state on removeAlertTag action', () => {
+    const reducer = createAlertTagsReducer();
+    const state = reducer(initialState, { type: 'removeAlertTag', value: 'False positive' });
+
+    expect(Array.from(state.tagsToRemove)).toEqual(['Duplicate', 'False positive']);
+    expect(Array.from(state.tagsToAdd)).toEqual([]);
+
+    // reducer action must not mutate previous state
+    expect(state.tagsToRemove).not.toBe(initialState.tagsToRemove);
+    expect(state.tagsToAdd).not.toBe(initialState.tagsToAdd);
+    expect(state).not.toBe(initialState);
+  });
+  it('should update state on setSelectableAlertTags action', () => {
+    const reducer = createAlertTagsReducer();
+    const state = reducer(initialState, {
+      type: 'setSelectableAlertTags',
+      value: [{ label: 'Duplicate' }],
+    });
+
+    expect(state.selectableAlertTags).toEqual([{ label: 'Duplicate' }]);
+    // reducer action must not mutate previous state
+    expect(state).not.toBe(initialState);
+  });
+});

x-pack/plugins/security_solution/public/common/components/toolbar/bulk_actions/reducer.ts

@@ -39,15 +39,21 @@ export const createAlertTagsReducer =
     switch (action.type) {
       case 'addAlertTag': {
         const { value } = action;
-        state.tagsToAdd.add(value);
-        state.tagsToRemove.delete(value);
-        return state;
+        const newTagsToAdd = new Set(state.tagsToAdd);
+        newTagsToAdd.add(value);
+        const newTagsToRemove = new Set(state.tagsToRemove);
+        newTagsToRemove.delete(value);
+
+        return { ...state, tagsToAdd: newTagsToAdd, tagsToRemove: newTagsToRemove };
       }
       case 'removeAlertTag': {
         const { value } = action;
-        state.tagsToRemove.add(value);
-        state.tagsToAdd.delete(value);
-        return state;
+        const newTagsToRemove = new Set(state.tagsToRemove);
+        newTagsToRemove.add(value);
+        const newTagsToAdd = new Set(state.tagsToAdd);
+        newTagsToAdd.delete(value);
+
+        return { ...state, tagsToAdd: newTagsToAdd, tagsToRemove: newTagsToRemove };
       }
       case 'setSelectableAlertTags': {
         const { value } = action;