test: add tests for NetworkButton component

frontend/__tests__/unit/components/NetworkButton.test.jsx

@@ -0,0 +1,39 @@
+import { render, screen } from "@testing-library/react";
+import NetworkButton from "components/HomeLoggedIn/components/NetworkButton";
+import { testNetwork } from "../../data/network";
+import { Router } from "react-router-dom";
+import { createMemoryHistory } from "history";
+
+describe("NetworkHeader", () => {
+  it("renders NetworkButton unchanged", () => {
+    const history = createMemoryHistory();
+
+    const { container } = render(
+      <Router history={history}>
+        <NetworkButton network={testNetwork} />
+      </Router>
+    );
+    expect(container).toMatchSnapshot();
+  });
+
+  test("renders NetworkHeader with a test network", () => {
+    const history = createMemoryHistory();
+
+    render(
+      <Router history={history}>
+        <NetworkButton network={testNetwork} />
+      </Router>
+    );
+
+    const networkButton = screen.getByRole("button", {
+      name: "0d303702cd0f1fc6 new-net-11166",
+    });
+
+    const networkLink = screen.getByRole("link", {
+      name: "0d303702cd0f1fc6 new-net-11166",
+    });
+
+    expect(networkButton).toBeInTheDocument();
+    expect(networkLink).toBeInTheDocument();
+  });
+});