feat: add WebStorage API (#7819)

This commit introduces localStorage and sessionStorage.

1 files changed, 42 insertions, 0 deletions

diff --git a/extensions/webstorage/lib.deno_webstorage.d.ts b/extensions/webstorage/lib.deno_webstorage.d.ts
new file mode 100644
index 000000000..bf438e005
--- /dev/null
+++ b/extensions/webstorage/lib.deno_webstorage.d.ts
@@ -0,0 +1,42 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+// deno-lint-ignore-file no-explicit-any
+
+/// <reference no-default-lib="true" />
+/// <reference lib="esnext" />
+
+/** This Web Storage API interface provides access to a particular domain's session or local storage. It allows, for example, the addition, modification, or deletion of stored data items. */
+interface Storage {
+  /**
+   * Returns the number of key/value pairs currently present in the list associated with the object.
+   */
+  readonly length: number;
+  /**
+   * Empties the list associated with the object of all key/value pairs, if there are any.
+   */
+  clear(): void;
+  /**
+   * Returns the current value associated with the given key, or null if the given key does not exist in the list associated with the object.
+   */
+  getItem(key: string): string | null;
+  /**
+   * Returns the name of the nth key in the list, or null if n is greater than or equal to the number of key/value pairs in the object.
+   */
+  key(index: number): string | null;
+  /**
+   * Removes the key/value pair with the given key from the list associated with the object, if a key/value pair with the given key exists.
+   */
+  removeItem(key: string): void;
+  /**
+   * Sets the value of the pair identified by key to value, creating a new key/value pair if none existed for key previously.
+   *
+   * Throws a "QuotaExceededError" DOMException exception if the new value couldn't be set. (Setting could fail if, e.g., the user has disabled storage for the site, or if the quota has been exceeded.)
+   */
+  setItem(key: string, value: string): void;
+  [name: string]: any;
+}
+
+declare var Storage: {
+  prototype: Storage;
+  new (): Storage;
+};