add config to exclude keys

Author: larscom

README.md

@@ -62,5 +62,10 @@ export interface Config<T> {
    * @param state the last state known before it gets saved to storage
    */
   saveIf: (state: T) => boolean
+
+  /**
+   * These keys will not get saved to storage
+   */
+  excludeKeys: Array<keyof T>
 }
 ```

package.json

@@ -5,6 +5,7 @@
     "ng": "ng",
     "start": "ng serve",
     "test": "ng test ngrx-signals-storage",
+    "test:watch": "ng test ngrx-signals-storage --watch",
     "build": "ng build ngrx-signals-storage && cpx README.md dist/ngrx-signals-storage"
   },
   "private": true,

projects/ngrx-signals-storage/jest.config.js

@@ -1,4 +1,5 @@
 module.exports = {
   preset: 'jest-preset-angular',
-  transformIgnorePatterns: ['node_modules/(?!.*\\.mjs$|@stomp/rx-stomp)']
+  transformIgnorePatterns: ['node_modules/(?!.*\\.mjs$|@stomp/rx-stomp)'],
+  setupFiles: ['./projects/ngrx-signals-storage/setup-jest.ts']
 }

projects/ngrx-signals-storage/setup-jest.ts

@@ -0,0 +1 @@
+Object.assign(global, { structuredClone: (val: any) => JSON.parse(JSON.stringify(val)) })

projects/ngrx-signals-storage/src/lib/config.ts

@@ -22,6 +22,11 @@ export interface Config<T> {
    * @param state the last state known before it gets saved to storage
    */
   saveIf: (state: T) => boolean
+
+  /**
+   * These keys will not get saved to storage
+   */
+  excludeKeys: Array<keyof T>
 }
 
 export const defaultConfig: Config<any> = {
@@ -31,5 +36,7 @@ export const defaultConfig: Config<any> = {
 
   deserialize: (state: string) => JSON.parse(state),
 
-  saveIf: (state: any) => true
+  saveIf: (state: any) => true,
+
+  excludeKeys: []
 }

projects/ngrx-signals-storage/src/lib/with-storage.spec.ts

@@ -269,6 +269,34 @@ describe('withStorage', () => {
 
     expect(error).toHaveBeenCalledWith(Error('storage error'))
   })
+
+  it('should exclude keys from state when saving to storage', () => {
+    const storage = new TestStorage()
+
+    const TestStore = signalStore(
+      withState({
+        count: 100,
+        excludeMe: 1,
+        skipMe: 'test'
+      }),
+      withStorage(storageKey, storage, { excludeKeys: ['excludeMe', 'skipMe'] })
+    )
+
+    TestBed.configureTestingModule({
+      providers: [TestStore]
+    })
+
+    const store = TestBed.inject(TestStore)
+    expect(store.count()).toBe(100)
+    expect(store.excludeMe()).toBe(1)
+    expect(store.skipMe()).toBe('test')
+
+    // trigger effect()
+    TestBed.flushEffects()
+
+    expect(storage.length).toEqual(1)
+    expect(JSON.parse(storage.getItem(storageKey)!)).toEqual({ count: 100 })
+  })
 })
 
 class TestStorage implements Storage {

projects/ngrx-signals-storage/src/lib/with-storage.ts

@@ -55,9 +55,12 @@ export function withStorage<State extends SignalStoreFeatureResult>(
     }
 
     effect(() => {
-      const state = getState(store)
+      const state = structuredClone(getState(store))
       try {
         if (cfg.saveIf(state)) {
+          cfg.excludeKeys.forEach((key) => {
+            delete state[key as keyof State['state']]
+          })
           storage.setItem(key, cfg.serialize(state))
         }
       } catch (e) {
@@ -69,7 +72,11 @@ export function withStorage<State extends SignalStoreFeatureResult>(
   }
 }
 
-function getFromStorage<T>(key: string, storage: Storage, cfg: Config<T>): string | null {
+function getFromStorage<State extends SignalStoreFeatureResult>(
+  key: string,
+  storage: Storage,
+  cfg: Config<State>
+): string | null {
   try {
     return storage.getItem(key)
   } catch (e) {

projects/ngrx-signals-storage/tsconfig.spec.json

@@ -3,12 +3,7 @@
   "extends": "../../tsconfig.json",
   "compilerOptions": {
     "outDir": "../../out-tsc/spec",
-    "types": [
-      "jest"
-    ]
+    "types": ["jest", "node"]
   },
-  "include": [
-    "**/*.spec.ts",
-    "**/*.d.ts"
-  ]
+  "include": ["**/*.spec.ts", "**/*.d.ts"]
 }

src/app/app.component.ts

@@ -8,9 +8,10 @@ import { patchState, signalStore, withMethods, withState } from '@ngrx/signals'
 export const CounterStore = signalStore(
   withState({
     count: 100,
+    test: 5,
     date: new Date()
   }),
-  withStorage('state', sessionStorage),
+  withStorage('state', sessionStorage, { excludeKeys: ['test'] }),
   withMethods(({ count, ...store }) => ({
     setDate(date: Date) {
       patchState(store, { date })

tsconfig.spec.json

@@ -4,7 +4,7 @@
   "compilerOptions": {
     "outDir": "./out-tsc/spec",
     "types": [
-      "jest"
+      "jest", "node"
     ]
   },
   "include": [