feat: improve OAuth error handling

Correctly read errors returned from the callback site. Also use a custom
error type, `OauthCancelledError`, when the OAuth flow is cancelled
because a user closed the popup window.

account-kit/signer/src/client/index.ts

@@ -1,4 +1,4 @@
-import { ConnectionConfigSchema } from "@aa-sdk/core";
+import { BaseError, ConnectionConfigSchema } from "@aa-sdk/core";
 import { getWebAuthnAttestation } from "@turnkey/http";
 import { IframeStamper } from "@turnkey/iframe-stamper";
 import { WebauthnStamper } from "@turnkey/webauthn-stamper";
@@ -451,7 +451,11 @@ export class AlchemySignerWebClient extends BaseSignerClient<ExportWalletParams>
         if (!event.data) {
           return;
         }
-        const { alchemyBundle: bundle, alchemyOrgId: orgId } = event.data;
+        const {
+          alchemyBundle: bundle,
+          alchemyOrgId: orgId,
+          alchemyError,
+        } = event.data;
         if (bundle && orgId) {
           cleanup();
           popup?.close();
@@ -460,6 +464,10 @@ export class AlchemySignerWebClient extends BaseSignerClient<ExportWalletParams>
             orgId,
             connectedEventName: "connectedOauth",
           }).then(resolve, reject);
+        } else if (alchemyError) {
+          cleanup();
+          popup?.close();
+          reject(new Error(alchemyError));
         }
       };
 
@@ -468,7 +476,7 @@ export class AlchemySignerWebClient extends BaseSignerClient<ExportWalletParams>
       const checkCloseIntervalId = setInterval(() => {
         if (popup?.closed) {
           cleanup();
-          reject(new Error("OAuth cancelled"));
+          reject(new OauthCancelledError());
         }
       }, CHECK_CLOSE_INTERVAL);
 
@@ -657,3 +665,19 @@ function resolveRelativeUrl(url: string): string {
   a.href = url;
   return a.href;
 }
+
+/**
+ * This error is thrown when the OAuth flow is cancelled because the auth popup
+ * window was closed.
+ */
+export class OauthCancelledError extends BaseError {
+  override name = "OauthCancelledError";
+
+  /**
+   * Constructor for initializing an error indicating that the OAuth flow was
+   * cancelled.
+   */
+  constructor() {
+    super("OAuth cancelled");
+  }
+}

account-kit/signer/src/index.ts

@@ -1,6 +1,6 @@
 export { BaseAlchemySigner } from "./base.js";
 export { BaseSignerClient } from "./client/base.js";
-export { AlchemySignerWebClient } from "./client/index.js";
+export { AlchemySignerWebClient, OauthCancelledError } from "./client/index.js";
 export type * from "./client/types.js";
 export { DEFAULT_SESSION_MS } from "./session/manager.js";
 export type * from "./signer.js";