Treat only AbortError as a cancelled OAuth refresh

Author: TheGreatAxios

src/mcp/oauth-provider.test.ts

@@ -784,7 +784,7 @@ describe("createOAuthProvider", () => {
 
     const pending = provider.refreshToken("refresh-me");
     while (seen.every((signal) => signal !== abort.signal)) await Promise.resolve();
-    abort.abort(new Error("toolset disposed"));
+    abort.abort(new DOMException("toolset disposed", "AbortError"));
     await expect(pending).rejects.toThrow("toolset disposed");
     await expect(pending).rejects.not.toBeInstanceOf(UnauthorizedError);
     expect(seen.some((signal) => signal === abort.signal)).toBe(true);

src/mcp/oauth-provider.ts

@@ -51,9 +51,7 @@ function redirectUrisInclude(
 }
 
 function isAbortError(err: unknown): boolean {
-  if (typeof err !== "object" || err === null) return false;
-  if ("name" in err && err.name === "AbortError") return true;
-  return err instanceof Error && err.name === "Error";
+  return typeof err === "object" && err !== null && "name" in err && err.name === "AbortError";
 }
 
 // Dynamic client registration bakes in the loopback redirect_uri (ephemeral port).