local storage wrapper with key prefix type

localstorage.wrapper.ts

export class StorageService {
  setItem (key: StorageKey, item: any): void {
    localStorage.setItem(key.toString(), item)
  }
}

export class StorageKey {

  private key: string
  constructor (prefix: StorageKeyPrefix, suffix: string) {
    this.key = `${prefix}-${suffix}`
  }

  public toString (): string {
    return this.key
  }
}

export type StorageKeyPrefix = 'Audit' | 'Input' | 'Answer'