LocalStorage helper class that automatically converts string values to their respective data types.

localstorage.js

class LocalStorage {
  static metadata = {}

  static set (key, value) {
    let storedValue = value
    if (typeof value === 'object') {
      storedValue = JSON.stringify(value)
    }
    if (!LocalStorage.metadata[key]) {
      LocalStorage.metadata[key] = {}
    }
    LocalStorage.metadata[key].type = typeof value
    window.localStorage.setItem(key, storedValue)
  }

  static get (key) {
    const result = window.localStorage.getItem(key)
    const metadata = LocalStorage.metadata[key]

    switch (metadata.type) {
      case 'object': {
        return JSON.parse(result)
      }
      case 'number': {
        return Number(result)
      }
      case 'boolean': {
        return result === 'true'
      }
      default: {
        return result
      }
    }
  }

  static exists (key) {
    return !!window.localStorage.getItem(key)
  }
}