Use localStorage with Web Storage API (#23172)

test/test_helper/local-storage-fallback.test.ts

@@ -0,0 +1,52 @@
+import { describe, test, expect, beforeEach } from "vitest";
+import { FallbackStorage } from "./local-storage-fallback";
+
+describe("FallbackStorage", () => {
+  let storage;
+
+  beforeEach(() => {
+    storage = new FallbackStorage();
+  });
+
+  test("should set and get an item", () => {
+    storage.setItem("key1", "value1");
+    expect(storage.getItem("key1")).toBe("value1");
+  });
+
+  test("should return null for non-existing item", () => {
+    expect(storage.getItem("nonExistingKey")).toBeNull();
+  });
+
+  test("should remove an item", () => {
+    storage.setItem("key2", "value2");
+    storage.removeItem("key2");
+    expect(storage.getItem("key2")).toBeNull();
+  });
+
+  test("should clear all items", () => {
+    storage.setItem("key3", "value3");
+    storage.setItem("key4", "value4");
+    storage.clear();
+    expect(storage.getItem("key3")).toBeNull();
+    expect(storage.getItem("key4")).toBeNull();
+  });
+
+  test("should return the correct key for an index", () => {
+    storage.setItem("key5", "value5");
+    storage.setItem("key6", "value6");
+    expect(storage.key(0)).toBe("key5");
+    expect(storage.key(1)).toBe("key6");
+  });
+
+  test("should throw TypeError if key method is called without arguments", () => {
+    expect(() => storage.key()).toThrow(TypeError);
+  });
+
+  test("should return the correct length", () => {
+    storage.setItem("key7", "value7");
+    storage.setItem("key8", "value8");
+    expect(storage.length).toBe(2);
+    storage.removeItem("key7");
+    expect(storage.length).toBe(1);
+  });
+});

test/test_helper/local-storage-fallback.ts

@@ -0,0 +1,38 @@
+export class FallbackStorage implements Storage {
+  private valuesMap = new Map();
+
+  getItem(key) {
+    const stringKey = String(key);
+    if (this.valuesMap.has(key)) {
+      return String(this.valuesMap.get(stringKey));
+    }
+    return null;
+  }
+
+  setItem(key, val) {
+    this.valuesMap.set(String(key), String(val));
+  }
+
+  removeItem(key) {
+    this.valuesMap.delete(key);
+  }
+
+  clear() {
+    this.valuesMap.clear();
+  }
+
+  key(i) {
+    if (arguments.length === 0) {
+      // this is a TypeError implemented on Chrome, Firefox throws Not enough arguments to Storage.key.
+      throw new TypeError(
+        "Failed to execute 'key' on 'Storage': 1 argument required, but only 0 present."
+      );
+    }
+    const arr = Array.from(this.valuesMap.keys());
+    return arr[i];
+  }
+
+  get length() {
+    return this.valuesMap.size;
+  }
+}