/**
 * The `IStorage` interface provides access to storage for the project. It essentially wraps a simple key-value storage engine based on [IndexedDB](https://www.construct.net/out?u=https%3a%2f%2fdeveloper.mozilla.org%2fen-US%2fdocs%2fWeb%2fAPI%2fIndexedDB_API). This means any data that can be stored in IndexedDB can be stored with these methods, such as numbers, strings, Blobs, etc. It is typically accessed by the [IRuntime](https://www.construct.net/en/make-games/manuals/construct-3/scripting/scripting-reference/iruntime) `storage` property.
 *
 * This interface accesses the same storage as the [Local Storage plugin](https://www.construct.net/en/make-games/manuals/construct-3/plugin-reference/local-storage). Therefore an item stored from the event sheet can also be read from script, and vice versa. Note however that Construct expressions can only be strings or numbers, so if a script stores a different type it cannot be used in the event sheet.
 *
 * As with the Local Storage plugin, the storage is unique to the specific project. It is not shared with any other projects or other website storage, even on the same origin.
 */
export class IStorage {
  /**
   * Read an item from storage. Returns a promise that resolves to the value of the item if it exists in storage, else `null` if the item does not exist in storage.
   *
   * **Note**: If an error occurs when reading from storage, this resolves with null instead of throwing an exception.
   */
  getItem(key: string): Promise<string | number>;
  /**
   * Write an item to storage. Returns a promise that resolves when the write has completed.
   *
   * **Note**: If the write fails - most commonly due to using up all available storage space - the promise will reject. To ensure this does not crash the game, ensure calls are in a try...catch block.
   */
  setItem(key: string, value: string | number): Promise<void>;
  /** Delete an item from storage. Returns a promise that resolves when the removal has completed. */
  removeItem(key: string): Promise<void>;
  /** Delete all items from storage. Returns a promise that resolves when the clear has completed. */
  clear(): Promise<void>;
  /** Retrieve a list of all keys in storage. Returns a promise that resolves to an array of key names. */
  keys(): Promise<string[]>;
}