fix: show error message when measureText API breaks in brave (#6336)

* fix: show error message when measureText API breaks in brave

* Add docs

* Add assets

* tweak message

* fix

* tweak message

* add translations

* lint

* fix

* fix

* lint

* lint

* lint please work now

* tweak doc

* fix

* split error component to new file

* add specs

* tweaks

Co-authored-by: David Luzar <luzar.david@gmail.com>

* wrap in div with a width of 30rem

* fix spec

* fix

* Fix typo

---------

Co-authored-by: David Luzar <luzar.david@gmail.com>
Co-authored-by: Daniel J. Geiger <1852529+DanielJGeiger@users.noreply.github.com>

src/components/App.test.tsx

@@ -0,0 +1,45 @@
+import ReactDOM from "react-dom";
+import * as Renderer from "../renderer/renderScene";
+import { reseed } from "../random";
+import { render, queryByTestId } from "../tests/test-utils";
+
+import ExcalidrawApp from "../excalidraw-app";
+
+const renderScene = jest.spyOn(Renderer, "renderScene");
+
+describe("Test <App/>", () => {
+  beforeEach(async () => {
+    // Unmount ReactDOM from root
+    ReactDOM.unmountComponentAtNode(document.getElementById("root")!);
+    localStorage.clear();
+    renderScene.mockClear();
+    reseed(7);
+  });
+
+  it("should show error modal when using brave and measureText API is not working", async () => {
+    (global.navigator as any).brave = {
+      isBrave: {
+        name: "isBrave",
+      },
+    };
+
+    const originalContext = global.HTMLCanvasElement.prototype.getContext("2d");
+    //@ts-ignore
+    global.HTMLCanvasElement.prototype.getContext = (contextId) => {
+      return {
+        ...originalContext,
+        measureText: () => ({
+          width: 0,
+        }),
+      };
+    };
+
+    await render(<ExcalidrawApp />);
+    expect(
+      queryByTestId(
+        document.querySelector(".excalidraw-modal-container")!,
+        "brave-measure-text-error",
+      ),
+    ).toMatchSnapshot();
+  });
+});