refactor(user): add config to toggle setting supertokens error handler as global error handler (#1007)

Author: rameshlohala

packages/user/src/index.ts

@@ -58,6 +58,7 @@ export { default as hasUserPermission } from "./lib/hasUserPermission";
 export { default as ProfileValidationClaim } from "./supertokens/utils/profileValidationClaim";
 export { default as createUserContext } from "./supertokens/utils/createUserContext";
 export { default as userSchema } from "./graphql/schema";
+export { errorHandler as supertokensErrorHandler } from "./supertokens/errorHandler";
 
 export * from "./migrations/queries";
 

packages/user/src/supertokens/errorHandler.ts

@@ -0,0 +1,17 @@
+import { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
+import { errorHandler as supertokensErrorHandler } from "supertokens-node/framework/fastify";
+
+export const errorHandler = (
+  error: Error,
+  request: FastifyRequest,
+  reply: FastifyReply,
+) => {
+  return (
+    supertokensErrorHandler() as unknown as (
+      this: FastifyInstance,
+      error: Error,
+      request: FastifyRequest,
+      reply: FastifyReply,
+    ) => Promise<void>
+  ).call(request.server, error, request, reply);
+};

packages/user/src/supertokens/plugin.ts

@@ -2,15 +2,13 @@ import cors from "@fastify/cors";
 import formDataPlugin from "@fastify/formbody";
 import FastifyPlugin from "fastify-plugin";
 import supertokens from "supertokens-node";
-import {
-  errorHandler,
-  plugin as supertokensPlugin,
-} from "supertokens-node/framework/fastify";
+import { plugin as supertokensPlugin } from "supertokens-node/framework/fastify";
 import { verifySession } from "supertokens-node/recipe/session/framework/fastify";
 
+import { errorHandler } from "./errorHandler";
 import init from "./init";
 
-import type { FastifyError, FastifyInstance } from "fastify";
+import type { FastifyInstance } from "fastify";
 
 const plugin = async (fastify: FastifyInstance) => {
   const { config, log } = fastify;
@@ -19,16 +17,9 @@ const plugin = async (fastify: FastifyInstance) => {
 
   init(fastify);
 
-  // Explicitly cast the errorHandler to the correct type
-  // [RL 2025-04-01] This should be fixed when supertokens-node is updated
-  fastify.setErrorHandler(
-    errorHandler() as unknown as (
-      this: FastifyInstance,
-      error: FastifyError,
-      request: import("fastify").FastifyRequest,
-      reply: import("fastify").FastifyReply,
-    ) => void,
-  );
+  if (config.user.supertokens.setErrorHandler !== false) {
+    fastify.setErrorHandler(errorHandler);
+  }
 
   await fastify.register(cors, {
     origin: config.appOrigin,

packages/user/src/supertokens/types/index.ts

@@ -47,6 +47,7 @@ interface SupertokensConfig {
   resetPasswordPath?: string;
   emailVerificationPath?: string;
   sendUserAlreadyExistsWarning?: boolean;
+  setErrorHandler?: boolean;
 }
 
 export type { SupertokensConfig, SupertokensRecipes };