Storage.ts

/**
 * The {@link Storage} is an unordered collection of named values of any
 * type. Values in the storage are named using `string` keys. The storage
 * can be therefore thought of as a `Map<string, *>`.....
 */
export abstract class Storage<V> {
  /**
   * This method is used to finalize the initialization of the storage after
   * the dependencies provided through the constructor have been prepared for
   * use.
   *
   * This method must be invoked only once and it must be the first method
   * invoked on this instance.
   *
   * @return This storage.
   */
  init(): this {
    return this;
  }

  /**
   * Returns `true` if the entry identified by the specified key exists
   * in this storage.
   *
   * @param key The key identifying the storage entry.
   * @return `true` if the storage entry exists.
   */
  has(key: string): boolean {
    return false;
  }

  /**
   * Retrieves the value of the entry identified by the specified . The
   * method returns `undefined` if the entry does not exists.
   *
   * Entries set to the `undefined` value can be tested for existence
   * using the `link has` method.
   *
   * @param key The key identifying the storage entry.
   * @return The value of the storage entry.
   */
  get(key: string): V | undefined {
    return undefined;
  }

  /**
   * Sets the storage entry identified by the specified key to the provided
   * value. The method creates the entry if it does not exist already.
   *
   * @param key The key identifying the storage entry.
   * @param value The storage entry value.
   * @return This storage.
   */
  set(key: string, value: V): this {
    return this;
  }

  /**
   * Deletes the entry identified by the specified key from this storage.
   *
   * @param key The key identifying the storage entry.
   * @return This storage.
   */
  delete(key: string): this {
    return this;
  }

  /**
   * Clears the storage of all entries.
   *
   * @return This storage.
   */
  clear(): this {
    return this;
  }

  /**
   * Returns an iterator for traversing the keys in this storage. The order
   * in which the keys are traversed is undefined.
   *
   * @return An iterator for traversing the keys in this
   *         storage. The iterator also implements the iterable protocol,
   *         returning itself as its own iterator, allowing it to be used in
   *         a `for..of` loop.
   */
  keys(): Iterable<string> {
    return [];
  }

  /**
   * Returns the number of entries in this storage.
   *
   * @return The number of entries in this storage.
   */
  size(): number {
    return 0;
  }
}