message: Use MockStorage in tests
diff: import { default as Service } from '@ember/service';
  +import { MockLocalStorage } from '../utils/browser-mocks';
  +import config from '../config/environment';
  interface WorkflowPersistencePersistedData {
  name: string;
  @@ -6,9 +8,20 @@ interface WorkflowPersistencePersistedData {
  }
  export default class WorkflowPersistence extends Service {
  + storage!: Storage | MockLocalStorage;
  +
  + constructor() {
  + super(...arguments);
  + if (config.environment === 'test') {
  + this.storage = new MockLocalStorage();
  + } else {
  + this.storage = window.localStorage;
  + }
  + }
  +
  getPersistedData(workflowPersistenceId: string) {
  return JSON.parse(
  - localStorage.getItem(`workflowPersistence:${workflowPersistenceId}`) ||
  + this.storage.getItem(`workflowPersistence:${workflowPersistenceId}`) ||
  '{}'
  );
  }
  @@ -17,7 +30,7 @@ export default class WorkflowPersistence extends Service {
  workflowPersistenceId: string,
  data: WorkflowPersistencePersistedData
  ) {
  - return localStorage.setItem(
  + return this.storage.setItem(
  `workflowPersistence:${workflowPersistenceId}`,
  JSON.stringify(data)
  );
  