Make bot review setup self-contained (#11)

Co-authored-by: Danny Kim <temeddix@gmail.com>
Co-committed-by: Danny Kim <temeddix@gmail.com>

auth_test.ts

@@ -0,0 +1,44 @@
+import { assertEquals } from "jsr:@std/assert@1";
+import { retryInvalidToken } from "./auth.ts";
+
+Deno.test("retries once after an invalid refresh token", async () => {
+  let attempts = 0;
+  let relogins = 0;
+  const result = await retryInvalidToken(
+    () =>
+      Promise.resolve({
+        status: { success: false },
+        error: attempts++ === 0 ? "invalid_refresh_token" : "still failed",
+      }),
+    () => {
+      relogins++;
+      return Promise.resolve();
+    },
+  );
+
+  assertEquals({ attempts, relogins, error: result.error }, {
+    attempts: 2,
+    relogins: 1,
+    error: "still failed",
+  });
+});
+
+Deno.test("does not retry an unrelated failure", async () => {
+  let attempts = 0;
+  let relogins = 0;
+  await retryInvalidToken(
+    () => {
+      attempts++;
+      return Promise.resolve({
+        status: { success: false },
+        error: "rate limited",
+      });
+    },
+    () => {
+      relogins++;
+      return Promise.resolve();
+    },
+  );
+
+  assertEquals({ attempts, relogins }, { attempts: 1, relogins: 0 });
+});