snapshot of https://github.com/excalidraw/excalidraw.git (master, 2026-09-16; blobs > 131072B omitted)

packages/excalidraw/tests/helpers/polyfills.ts

@@ -0,0 +1,135 @@
+import { URL } from "node:url";
+
+class ClipboardEvent {
+  constructor(
+    type: "paste" | "copy",
+    eventInitDict: {
+      clipboardData: DataTransfer;
+    },
+  ) {
+    return Object.assign(
+      new Event("paste", {
+        bubbles: true,
+        cancelable: true,
+        composed: true,
+      }),
+      {
+        clipboardData: eventInitDict.clipboardData,
+      },
+    ) as any as ClipboardEvent;
+  }
+}
+
+type DataKind = "string" | "file";
+
+class DataTransferItem {
+  kind: DataKind;
+  type: string;
+  data: string | Blob;
+
+  constructor(kind: DataKind, type: string, data: string | Blob) {
+    this.kind = kind;
+    this.type = type;
+    this.data = data;
+  }
+
+  getAsString(callback: (data: string) => void): void {
+    if (this.kind === "string") {
+      callback(this.data as string);
+    }
+  }
+
+  getAsFile(): File | null {
+    if (this.kind === "file" && this.data instanceof File) {
+      return this.data;
+    }
+    return null;
+  }
+}
+
+class DataTransferItemList extends Array<DataTransferItem> {
+  add(data: string | File, type: string = ""): void {
+    if (typeof data === "string") {
+      this.push(new DataTransferItem("string", type, data));
+    } else if (data instanceof File) {
+      this.push(new DataTransferItem("file", type, data));
+    }
+  }
+
+  clear(): void {
+    this.clear();
+  }
+}
+
+class DataTransfer {
+  public items: DataTransferItemList = new DataTransferItemList();
+
+  get files() {
+    return this.items
+      .filter((item) => item.kind === "file")
+      .map((item) => item.getAsFile()!);
+  }
+
+  add(data: string | File, type: string = ""): void {
+    if (typeof data === "string") {
+      this.items.add(data, type);
+    } else {
+      this.items.add(data);
+    }
+  }
+
+  setData(type: string, value: string) {
+    this.items.add(value, type);
+  }
+
+  getData(type: string) {
+    return this.items.find((item) => item.type === type)?.data || "";
+  }
+}
+
+export const testPolyfills = {
+  ClipboardEvent,
+  DataTransfer,
+  DataTransferItem,
+  // https://github.com/vitest-dev/vitest/pull/4164#issuecomment-2172729965
+  URL,
+};
+
+export const PolyfillLocalStorage = () => {
+  // Node.js 25+ provides a native localStorage global that shadows jsdom's,
+  // and jsdom's own localStorage also uses the native one -- both are broken
+  // (empty objects without Storage methods). On older Node versions, jsdom
+  // provides a working localStorage. This polyfill replaces localStorage on
+  // all supported versions with a standard Storage implementation backed by
+  // a Map, ensuring consistent behavior regardless of the Node.js version.
+  const storage = new Map<string, string>();
+  const storagePolyfill: Storage = {
+    get length() {
+      return storage.size;
+    },
+    clear() {
+      storage.clear();
+    },
+    key(index) {
+      return Array.from(storage.keys())[index] ?? null;
+    },
+    getItem(key) {
+      return storage.get(key) ?? null;
+    },
+    setItem(key, value) {
+      storage.set(key, value);
+    },
+    removeItem(key) {
+      storage.delete(key);
+    },
+    *[Symbol.iterator]() {
+      yield* storage.entries();
+    },
+  };
+
+  Object.defineProperty(window, "localStorage", {
+    value: storagePolyfill,
+    writable: true,
+    configurable: true,
+  });
+};