test(ui): add vitest coverage for the 3 new OAuth login components

CONTRIBUTING.md requires corresponding tests for new UI components.
Adds:

- OAuthDeviceLoginButton.test.tsx (6 cases) — Sign-in button disabled
  state, startCall invocation, user-code + verification-URL rendering,
  onSuccess callback on poll success, error-state rendering on poll
  failure, and cancel flow.
- ChatGPTLoginButton.test.tsx (1 case) — renders with the ChatGPT label.
- CopilotLoginButton.test.tsx (1 case) — renders with the GitHub Copilot
  label.

Real timers throughout; polling tests wait up to 10s for the 3s-interval
first poll to fire. 20/20 local tests pass across my new + adjacent
existing UI test files; ``npm run build`` succeeds.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ui/litellm-dashboard/src/components/model_add/ChatGPTLoginButton.test.tsx

@@ -0,0 +1,26 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import ChatGPTLoginButton from "./ChatGPTLoginButton";
+
+vi.mock("@/app/(dashboard)/hooks/useAuthorized", () => ({
+  default: () => ({ accessToken: "test-token" }),
+}));
+
+vi.mock("@/components/networking", async () => {
+  const actual = await vi.importActual("@/components/networking");
+  return {
+    ...actual,
+    chatgptOauthStartCall: vi.fn(),
+    chatgptOauthStatusCall: vi.fn(),
+    chatgptOauthCancelCall: vi.fn(),
+  };
+});
+
+describe("ChatGPTLoginButton", () => {
+  it("renders with the ChatGPT provider label", () => {
+    render(<ChatGPTLoginButton credentialName="c" onSuccess={vi.fn()} />);
+    expect(
+      screen.getByRole("button", { name: /Sign in with ChatGPT/i }),
+    ).toBeInTheDocument();
+  });
+});

ui/litellm-dashboard/src/components/model_add/CopilotLoginButton.test.tsx

@@ -0,0 +1,26 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import CopilotLoginButton from "./CopilotLoginButton";
+
+vi.mock("@/app/(dashboard)/hooks/useAuthorized", () => ({
+  default: () => ({ accessToken: "test-token" }),
+}));
+
+vi.mock("@/components/networking", async () => {
+  const actual = await vi.importActual("@/components/networking");
+  return {
+    ...actual,
+    copilotOauthStartCall: vi.fn(),
+    copilotOauthStatusCall: vi.fn(),
+    copilotOauthCancelCall: vi.fn(),
+  };
+});
+
+describe("CopilotLoginButton", () => {
+  it("renders with the GitHub Copilot provider label", () => {
+    render(<CopilotLoginButton credentialName="c" onSuccess={vi.fn()} />);
+    expect(
+      screen.getByRole("button", { name: /Sign in with GitHub Copilot/i }),
+    ).toBeInTheDocument();
+  });
+});

ui/litellm-dashboard/src/components/model_add/OAuthDeviceLoginButton.test.tsx

@@ -0,0 +1,170 @@
+import { act, fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import OAuthDeviceLoginButton from "./OAuthDeviceLoginButton";
+
+vi.mock("@/app/(dashboard)/hooks/useAuthorized", () => ({
+  default: () => ({ accessToken: "test-token" }),
+}));
+
+describe("OAuthDeviceLoginButton", () => {
+  beforeEach(() => {
+    vi.useRealTimers();
+  });
+
+  const baseProps = {
+    providerLabel: "ChatGPT",
+    startCall: vi.fn(),
+    statusCall: vi.fn(),
+    cancelCall: vi.fn(),
+    onSuccess: vi.fn(),
+  };
+
+  it("disables Sign-in when no credential name is provided", () => {
+    render(<OAuthDeviceLoginButton {...baseProps} onSuccess={vi.fn()} />);
+    const button = screen.getByRole("button", { name: /Sign in with ChatGPT/i });
+    expect(button).toBeDisabled();
+  });
+
+  it("enables Sign-in once a credential name is provided", () => {
+    render(
+      <OAuthDeviceLoginButton
+        {...baseProps}
+        credentialName="my-creds"
+        onSuccess={vi.fn()}
+      />,
+    );
+    expect(
+      screen.getByRole("button", { name: /Sign in with ChatGPT/i }),
+    ).toBeEnabled();
+  });
+
+  it("on Sign-in click, shows the user code and verification URL returned by startCall", async () => {
+    const startCall = vi.fn().mockResolvedValue({
+      session_id: "sess-1",
+      user_code: "ABCD-1234",
+      verification_url: "https://auth.example/code",
+      interval: 5,
+    });
+    const statusCall = vi.fn().mockResolvedValue({ status: "pending" });
+
+    render(
+      <OAuthDeviceLoginButton
+        {...baseProps}
+        credentialName="my-creds"
+        startCall={startCall}
+        statusCall={statusCall}
+        cancelCall={vi.fn()}
+        onSuccess={vi.fn()}
+      />,
+    );
+
+    fireEvent.click(screen.getByRole("button", { name: /Sign in with ChatGPT/i }));
+
+    await waitFor(() => {
+      expect(screen.getByText("ABCD-1234")).toBeInTheDocument();
+    });
+    expect(
+      screen.getByRole("link", { name: "https://auth.example/code" }),
+    ).toHaveAttribute("href", "https://auth.example/code");
+    expect(startCall).toHaveBeenCalledWith("test-token", "my-creds");
+  });
+
+  it("calls onSuccess when polling reports success", async () => {
+    const onSuccess = vi.fn();
+    const startCall = vi.fn().mockResolvedValue({
+      session_id: "sess-1",
+      user_code: "CODE",
+      verification_url: "https://auth.example/code",
+      interval: 5,
+    });
+    const statusCall = vi.fn().mockResolvedValue({ status: "success" });
+
+    render(
+      <OAuthDeviceLoginButton
+        {...baseProps}
+        credentialName="my-creds"
+        startCall={startCall}
+        statusCall={statusCall}
+        cancelCall={vi.fn()}
+        onSuccess={onSuccess}
+      />,
+    );
+    fireEvent.click(screen.getByRole("button", { name: /Sign in with ChatGPT/i }));
+
+    // Poll interval is 3s; allow up to 10s of real time for the first poll
+    // to fire and resolve with status=success.
+    await waitFor(
+      () => {
+        expect(onSuccess).toHaveBeenCalledTimes(1);
+      },
+      { timeout: 10000 },
+    );
+  }, 15000);
+
+  it("surfaces error status from polling", async () => {
+    const startCall = vi.fn().mockResolvedValue({
+      session_id: "sess-1",
+      user_code: "CODE",
+      verification_url: "https://auth.example/code",
+      interval: 5,
+    });
+    const statusCall = vi
+      .fn()
+      .mockResolvedValue({ status: "error", message: "upstream failure" });
+
+    render(
+      <OAuthDeviceLoginButton
+        {...baseProps}
+        credentialName="my-creds"
+        startCall={startCall}
+        statusCall={statusCall}
+        cancelCall={vi.fn()}
+        onSuccess={vi.fn()}
+      />,
+    );
+    fireEvent.click(screen.getByRole("button", { name: /Sign in with ChatGPT/i }));
+
+    await waitFor(
+      () => {
+        expect(screen.getByText("upstream failure")).toBeInTheDocument();
+      },
+      { timeout: 10000 },
+    );
+  }, 15000);
+
+  it("on Cancel click, calls cancelCall and returns to idle state", async () => {
+    const cancelCall = vi.fn().mockResolvedValue(undefined);
+    const startCall = vi.fn().mockResolvedValue({
+      session_id: "sess-1",
+      user_code: "CODE",
+      verification_url: "https://auth.example/code",
+      interval: 5,
+    });
+    const statusCall = vi.fn().mockResolvedValue({ status: "pending" });
+
+    render(
+      <OAuthDeviceLoginButton
+        {...baseProps}
+        credentialName="my-creds"
+        startCall={startCall}
+        statusCall={statusCall}
+        cancelCall={cancelCall}
+        onSuccess={vi.fn()}
+      />,
+    );
+    fireEvent.click(screen.getByRole("button", { name: /Sign in with ChatGPT/i }));
+    await waitFor(() => {
+      expect(screen.getByText("CODE")).toBeInTheDocument();
+    });
+
+    fireEvent.click(screen.getByRole("button", { name: /Cancel/i }));
+
+    await waitFor(() => {
+      expect(cancelCall).toHaveBeenCalledWith("test-token", "sess-1");
+    });
+    // Back to idle — Sign-in button visible again
+    expect(
+      screen.getByRole("button", { name: /Sign in with ChatGPT/i }),
+    ).toBeInTheDocument();
+  });
+});