feat: add extensive test suite

app/api/auth/[...all]/handler.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, mock, test } from "bun:test";
+import { createAuthHandlers } from "./handler";
+
+describe("auth route factory", () => {
+  test("creates both handlers from the provided auth instance", async () => {
+    const auth = { name: "auth" };
+    const get = mock(async (_request: Request) => new Response("GET"));
+    const post = mock(async (_request: Request) => new Response("POST"));
+    const adapter = mock((_auth: typeof auth) => ({ GET: get, POST: post }));
+    const handlers = createAuthHandlers(adapter, auth);
+    expect(adapter).toHaveBeenCalledWith(auth);
+    expect(
+      await (await handlers.GET(new Request("https://buzz.test"))).text(),
+    ).toBe("GET");
+    expect(
+      await (
+        await handlers.POST(
+          new Request("https://buzz.test", { method: "POST" }),
+        )
+      ).text(),
+    ).toBe("POST");
+  });
+});

app/api/auth/[...all]/handler.ts

@@ -0,0 +1,8 @@
+type AuthHandler = (request: Request) => Response | Promise<Response>;
+
+export function createAuthHandlers<TAuth>(
+  toHandler: (auth: TAuth) => { GET: AuthHandler; POST: AuthHandler },
+  auth: TAuth,
+) {
+  return toHandler(auth);
+}

app/api/auth/[...all]/route.ts

@@ -1,4 +1,5 @@
 import { toNextJsHandler } from "better-auth/next-js";
 import { auth } from "@/lib/auth"; // path to your auth file
+import { createAuthHandlers } from "./handler";
 
-export const { POST, GET } = toNextJsHandler(auth);
+export const { POST, GET } = createAuthHandlers(toNextJsHandler, auth);