feat(editor): mermaid code editor & improve parsing (#10897)

packages/excalidraw/tests/MermaidToExcalidraw.test.tsx

@@ -1,5 +1,4 @@
-import React from "react";
-import { expect } from "vitest";
+import { expect, vi } from "vitest";
 
 import { Excalidraw } from "../index";
 
@@ -7,6 +6,13 @@ import { mockMermaidToExcalidraw } from "./helpers/mocks";
 import { getTextEditor, updateTextEditor } from "./queries/dom";
 import { render, waitFor } from "./test-utils";
 
+// Mock CodeMirror deps so the dynamic import of CodeMirrorEditor fails,
+// causing TTDDialogInput to fall back to <textarea> in tests.
+vi.mock("@codemirror/view", () => ({}));
+vi.mock("@codemirror/state", () => ({}));
+vi.mock("@codemirror/language", () => ({}));
+vi.mock("@lezer/highlight", () => ({}));
+
 mockMermaidToExcalidraw({
   mockRef: true,
   parseMermaidToExcalidraw: async (definition) => {