test: fix mermaid test flake (#7249)

src/tests/MermaidToExcalidraw.test.tsx

@@ -1,4 +1,4 @@
-import { act, fireEvent, render } from "./test-utils";
+import { act, fireEvent, render, waitFor } from "./test-utils";
 import { Excalidraw } from "../packages/excalidraw/index";
 import React from "react";
 import { expect, vi } from "vitest";
@@ -111,7 +111,7 @@ describe("Test <MermaidToExcalidraw/>", () => {
 
   it("should open mermaid popup when active tool is mermaid", async () => {
     const dialog = document.querySelector(".dialog-mermaid")!;
-
+    await waitFor(() => dialog.querySelector("canvas"));
     expect(dialog.outerHTML).toMatchSnapshot();
   });
 

src/tests/__snapshots__/MermaidToExcalidraw.test.tsx.snap

@@ -6,5 +6,5 @@ exports[`Test <MermaidToExcalidraw/> > should open mermaid popup when active too
  B --&gt; C{Let me think}
  C --&gt;|One| D[Laptop]
  C --&gt;|Two| E[iPhone]
- C --&gt;|Three| F[Car]</textarea></div><div class=\\"dialog-mermaid-panels-preview\\"><label>Preview</label><div class=\\"dialog-mermaid-panels-preview-wrapper\\"><div style=\\"opacity: 1;\\" class=\\"dialog-mermaid-panels-preview-canvas-container\\"></div></div></div></div><div class=\\"dialog-mermaid-buttons\\"><button type=\\"button\\" class=\\"excalidraw-button dialog-mermaid-insert\\">Insert<span><svg aria-hidden=\\"true\\" focusable=\\"false\\" role=\\"img\\" viewBox=\\"0 0 20 20\\" class=\\"\\" fill=\\"none\\" stroke=\\"currentColor\\" stroke-linecap=\\"round\\" stroke-linejoin=\\"round\\"><g stroke-width=\\"1.25\\"><path d=\\"M4.16602 10H15.8327\\"></path><path d=\\"M12.5 13.3333L15.8333 10\\"></path><path d=\\"M12.5 6.66666L15.8333 9.99999\\"></path></g></svg></span></button></div></div></div></div></div></div>"
+ C --&gt;|Three| F[Car]</textarea></div><div class=\\"dialog-mermaid-panels-preview\\"><label>Preview</label><div class=\\"dialog-mermaid-panels-preview-wrapper\\"><div style=\\"opacity: 1;\\" class=\\"dialog-mermaid-panels-preview-canvas-container\\"><canvas width=\\"89\\" height=\\"158\\" dir=\\"ltr\\"></canvas></div></div></div></div><div class=\\"dialog-mermaid-buttons\\"><button type=\\"button\\" class=\\"excalidraw-button dialog-mermaid-insert\\">Insert<span><svg aria-hidden=\\"true\\" focusable=\\"false\\" role=\\"img\\" viewBox=\\"0 0 20 20\\" class=\\"\\" fill=\\"none\\" stroke=\\"currentColor\\" stroke-linecap=\\"round\\" stroke-linejoin=\\"round\\"><g stroke-width=\\"1.25\\"><path d=\\"M4.16602 10H15.8327\\"></path><path d=\\"M12.5 13.3333L15.8333 10\\"></path><path d=\\"M12.5 6.66666L15.8333 9.99999\\"></path></g></svg></span></button></div></div></div></div></div></div>"
 `;