Add some auth tests

src/__tests__/pages/api/auth/[...nextauth].test.js

@@ -0,0 +1,100 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const { nextAuthMock } = vi.hoisted(() => ({
+  nextAuthMock: vi.fn((options) => ({ options })),
+}));
+
+vi.mock("next-auth", () => ({
+  default: nextAuthMock,
+}));
+
+describe("pages/api/auth/[...nextauth]", () => {
+  const originalEnv = process.env;
+
+  beforeEach(() => {
+    vi.resetModules();
+    nextAuthMock.mockClear();
+    process.env = { ...originalEnv };
+    delete process.env.NEXTAUTH_SECRET;
+    delete process.env.NEXTAUTH_URL;
+  });
+
+  it("configures no providers when auth is disabled", async () => {
+    const mod = await import("pages/api/auth/[...nextauth]");
+
+    expect(nextAuthMock).toHaveBeenCalledTimes(1);
+    expect(mod.default.options.providers).toEqual([]);
+    expect(mod.default.options.pages?.signIn).toBe("/auth/signin");
+  });
+
+  it("maps HOMEPAGE_AUTH_SECRET and HOMEPAGE_EXTERNAL_URL to NextAuth envs", async () => {
+    process.env.HOMEPAGE_AUTH_SECRET = "secret";
+    process.env.HOMEPAGE_EXTERNAL_URL = "https://homepage.example";
+
+    const mod = await import("pages/api/auth/[...nextauth]");
+
+    expect(process.env.NEXTAUTH_SECRET).toBe("secret");
+    expect(process.env.NEXTAUTH_URL).toBe("https://homepage.example");
+    expect(mod.default.options.secret).toBe("secret");
+  });
+
+  it("throws when auth is enabled but required settings are missing", async () => {
+    process.env.HOMEPAGE_AUTH_ENABLED = "true";
+
+    await expect(import("pages/api/auth/[...nextauth]")).rejects.toThrow(
+      /OIDC auth is enabled but required settings are missing/i,
+    );
+  });
+
+  it("builds an OIDC provider when enabled and maps profile fields", async () => {
+    process.env.HOMEPAGE_AUTH_ENABLED = "true";
+    process.env.HOMEPAGE_OIDC_ISSUER = "https://issuer.example/";
+    process.env.HOMEPAGE_OIDC_CLIENT_ID = "client-id";
+    process.env.HOMEPAGE_OIDC_CLIENT_SECRET = "client-secret";
+    process.env.HOMEPAGE_AUTH_SECRET = "auth-secret";
+    process.env.HOMEPAGE_EXTERNAL_URL = "https://homepage.example";
+    process.env.HOMEPAGE_OIDC_NAME = "My OIDC";
+    process.env.HOMEPAGE_OIDC_SCOPE = "openid email";
+
+    const mod = await import("pages/api/auth/[...nextauth]");
+    const [provider] = mod.default.options.providers;
+
+    expect(provider).toMatchObject({
+      id: "homepage-oidc",
+      name: "My OIDC",
+      type: "oauth",
+      idToken: true,
+      issuer: "https://issuer.example",
+      wellKnown: "https://issuer.example/.well-known/openid-configuration",
+      clientId: "client-id",
+      clientSecret: "client-secret",
+    });
+    expect(provider.authorization.params.scope).toBe("openid email");
+
+    expect(
+      provider.profile({
+        sub: "sub",
+        preferred_username: "user",
+        email: "user@example.com",
+        picture: "https://example.com/p.png",
+      }),
+    ).toEqual({
+      id: "sub",
+      name: "user",
+      email: "user@example.com",
+      image: "https://example.com/p.png",
+    });
+
+    expect(
+      provider.profile({
+        id: "id",
+        name: "name",
+      }),
+    ).toEqual({
+      id: "id",
+      name: "name",
+      email: null,
+      image: null,
+    });
+  });
+});