Initial MRP foundation scaffold

client/src/tests/setup.ts

@@ -0,0 +1,2 @@
+import "@testing-library/jest-dom/vitest";
+

client/src/tests/theme.test.tsx

@@ -0,0 +1,20 @@
+import { fireEvent, render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+
+import { ThemeProvider } from "../theme/ThemeProvider";
+import { ThemeToggle } from "../components/ThemeToggle";
+
+describe("ThemeToggle", () => {
+  it("toggles the html dark class", () => {
+    render(
+      <ThemeProvider>
+        <ThemeToggle />
+      </ThemeProvider>
+    );
+
+    fireEvent.click(screen.getByRole("button"));
+
+    expect(document.documentElement.classList.contains("dark")).toBe(true);
+  });
+});
+