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

packages/excalidraw/tests/helpers/mocks.ts

@@ -0,0 +1,111 @@
+import * as MermaidToExcalidraw from "@excalidraw/mermaid-to-excalidraw";
+import React from "react";
+import { vi } from "vitest";
+
+import type { parseMermaidToExcalidraw } from "@excalidraw/mermaid-to-excalidraw";
+import type { throttleRAF as throttleRAFType } from "@excalidraw/common";
+
+type ThrottledFn<T extends unknown[]> = ((...args: T) => void) & {
+  flush: () => void;
+  cancel: () => void;
+};
+
+export const mockThrottleRAF: typeof throttleRAFType = <T extends unknown[]>(
+  fn: (...args: T) => void,
+) => {
+  const ret = ((...args: T) => {
+    fn(...args);
+  }) as ThrottledFn<T>;
+
+  ret.flush = () => {};
+  ret.cancel = () => {};
+
+  return ret;
+};
+
+export const mockMermaidToExcalidraw = (opts: {
+  parseMermaidToExcalidraw: typeof parseMermaidToExcalidraw;
+  mockRef?: boolean;
+}) => {
+  vi.mock("@excalidraw/mermaid-to-excalidraw", async (importActual) => {
+    const module = (await importActual()) as any;
+
+    return {
+      __esModule: true,
+      ...module,
+    };
+  });
+  const parseMermaidToExcalidrawSpy = vi.spyOn(
+    MermaidToExcalidraw,
+    "parseMermaidToExcalidraw",
+  );
+
+  parseMermaidToExcalidrawSpy.mockImplementation(opts.parseMermaidToExcalidraw);
+
+  if (opts.mockRef) {
+    vi.spyOn(React, "useRef").mockReturnValue({
+      current: {
+        parseMermaidToExcalidraw: parseMermaidToExcalidrawSpy,
+      },
+    });
+  }
+};
+
+// Mock for HTMLImageElement (use with `vi.unstubAllGlobals()`)
+// as jsdom.resources: "usable" throws an error on image load
+export const mockHTMLImageElement = (
+  naturalWidth: number,
+  naturalHeight: number,
+) => {
+  vi.stubGlobal(
+    "Image",
+    class extends Image {
+      constructor() {
+        super();
+
+        Object.defineProperty(this, "naturalWidth", {
+          value: naturalWidth,
+        });
+        Object.defineProperty(this, "naturalHeight", {
+          value: naturalHeight,
+        });
+
+        queueMicrotask(() => {
+          this.onload?.({} as Event);
+        });
+      }
+    },
+  );
+};
+
+// Mocks for multiple HTMLImageElements (dimensions are assigned in the order of image initialization)
+export const mockMultipleHTMLImageElements = (
+  sizes: (readonly [number, number])[],
+) => {
+  const _sizes = [...sizes];
+
+  vi.stubGlobal(
+    "Image",
+    class extends Image {
+      constructor() {
+        super();
+
+        const size = _sizes.shift();
+        if (!size) {
+          throw new Error("Insufficient sizes");
+        }
+
+        Object.defineProperty(this, "naturalWidth", {
+          value: size[0],
+        });
+        Object.defineProperty(this, "naturalHeight", {
+          value: size[1],
+        });
+
+        queueMicrotask(() => {
+          this.onload?.({} as Event);
+        });
+      }
+    },
+  );
+};