✨ Implement Local Storage store

Author: yannickadam

packages/core/src/domain/session/sessionLocalStorageStore.spec.ts

@@ -0,0 +1,42 @@
+import { LOCAL_STORAGE_KEY, initLocalStorage } from './sessionLocalStorageStore'
+import type { SessionState, SessionStore } from './sessionStore'
+
+describe('session local storage store', () => {
+  const sessionState: SessionState = { id: '123', created: '0' }
+  let localStorageStore: SessionStore
+
+  beforeEach(() => {
+    localStorageStore = initLocalStorage()
+  })
+
+  afterEach(() => {
+    window.localStorage.clear()
+  })
+
+  it('should persist a session in local storage', () => {
+    localStorageStore.persistSession(sessionState)
+    const session = localStorageStore.retrieveSession()
+    expect(session).toEqual({ ...sessionState })
+  })
+
+  it('should delete the local storage item holding the session', () => {
+    localStorageStore.persistSession(sessionState)
+    localStorageStore.clearSession()
+    const session = localStorageStore.retrieveSession()
+    expect(session).toEqual({})
+  })
+
+  it('should not interfere with other keys present in local storage', () => {
+    window.localStorage.setItem('test', 'hello')
+    localStorageStore.persistSession(sessionState)
+    localStorageStore.retrieveSession()
+    localStorageStore.clearSession()
+    expect(window.localStorage.getItem('test')).toEqual('hello')
+  })
+
+  it('should return an empty object if session string is invalid', () => {
+    window.localStorage.setItem(LOCAL_STORAGE_KEY, '{test:42}')
+    const session = localStorageStore.retrieveSession()
+    expect(session).toEqual({})
+  })
+})

packages/core/src/domain/session/sessionLocalStorageStore.ts

@@ -0,0 +1,25 @@
+import type { SessionState, SessionStore } from './sessionStore'
+import { toSessionString, sessionStringToSessionState } from './sessionStore'
+
+export const LOCAL_STORAGE_KEY = '_dd_s'
+
+export function initLocalStorage(): SessionStore {
+  return {
+    persistSession: persistInLocalStorage,
+    retrieveSession: retrieveSessionFromLocalStorage,
+    clearSession: clearSessionFromLocalStorage,
+  }
+}
+
+function persistInLocalStorage(sessionState: SessionState) {
+  localStorage.setItem(LOCAL_STORAGE_KEY, toSessionString(sessionState))
+}
+
+function retrieveSessionFromLocalStorage(): SessionState {
+  const sessionString = localStorage.getItem(LOCAL_STORAGE_KEY)
+  return sessionStringToSessionState(sessionString)
+}
+
+function clearSessionFromLocalStorage() {
+  localStorage.removeItem(LOCAL_STORAGE_KEY)
+}