fix: wrap promise on server runtime

Author: danielpza

src/_plugin.ts

@@ -66,10 +66,6 @@ export function wrapFetch(server: Server, fetchHandler: ServerHandler) {
       }
     }
 
-    if (resPromise && server.options.onError) {
-      resPromise = resPromise.catch(server.options.onError);
-    }
-
     // Response hooks
     if (hasResponseHooks) {
       for (const resHook of responseHooks) {

src/_utils.ts

@@ -1,4 +1,4 @@
-import type { ServerOptions } from "./types";
+import type { ErrorHandler, ServerHandler, ServerOptions } from "./types";
 
 import { readFileSync } from "node:fs";
 
@@ -67,3 +67,21 @@ function resolveCertOrKey(value?: unknown): undefined | string {
   }
   return readFileSync(value, "utf8");
 }
+
+export function wrapFetchOnError(
+  fetchHandler: ServerHandler,
+  onError?: ErrorHandler,
+): ServerHandler {
+  if (!onError) return fetchHandler;
+  return (...params) => {
+    try {
+      const result = fetchHandler(...params);
+      if (result instanceof Promise) {
+        return result.catch(onError);
+      }
+      return result;
+    } catch (error) {
+      return onError(error as Error);
+    }
+  };
+}

src/adapters/bun.ts

@@ -1,6 +1,6 @@
 import type { BunFetchHandler, Server, ServerOptions } from "../types.ts";
 import type * as bun from "bun";
-import { resolvePort, resolveTLSOptions } from "../_utils.ts";
+import { resolvePort, resolveTLSOptions, wrapFetchOnError } from "../_utils.ts";
 import { wrapFetch } from "../_plugin.ts";
 
 export const Response = globalThis.Response;
@@ -21,7 +21,9 @@ class BunServer implements Server<BunFetchHandler> {
   constructor(options: ServerOptions) {
     this.options = options;
 
-    const fetchHandler = wrapFetch(this, this.options.fetch);
+    let fetchHandler = this.options.fetch;
+    fetchHandler = wrapFetchOnError(this.options.fetch, this.options.onError);
+    fetchHandler = wrapFetch(this as unknown as Server, fetchHandler);
 
     this.fetch = (request, server) => {
       Object.defineProperties(request, {

src/adapters/cloudflare.ts

@@ -5,6 +5,7 @@ import type {
 } from "../types.ts";
 import type * as CF from "@cloudflare/workers-types";
 import { wrapFetch } from "../_plugin.ts";
+import { wrapFetchOnError } from "../_utils.ts";
 
 export const Response = globalThis.Response;
 
@@ -23,10 +24,9 @@ class CloudflareServer implements Server<CloudflareFetchHandler> {
   constructor(options: ServerOptions) {
     this.options = options;
 
-    const fetchHandler = wrapFetch(
-      this as unknown as Server,
-      this.options.fetch,
-    );
+    let fetchHandler = this.options.fetch;
+    fetchHandler = wrapFetchOnError(this.options.fetch, this.options.onError);
+    fetchHandler = wrapFetch(this as unknown as Server, fetchHandler);
 
     this.fetch = (request, env, context) => {
       Object.defineProperties(request, {

src/adapters/deno.ts

@@ -1,5 +1,10 @@
 import type { DenoFetchHandler, Server, ServerOptions } from "../types.ts";
-import { fmtURL, resolvePort, resolveTLSOptions } from "../_utils.ts";
+import {
+  fmtURL,
+  resolvePort,
+  resolveTLSOptions,
+  wrapFetchOnError,
+} from "../_utils.ts";
 import { wrapFetch } from "../_plugin.ts";
 
 export const Response = globalThis.Response;
@@ -25,7 +30,9 @@ class DenoServer implements Server<DenoFetchHandler> {
   constructor(options: ServerOptions) {
     this.options = options;
 
-    const fetchHandler = wrapFetch(this, this.options.fetch);
+    let fetchHandler = this.options.fetch;
+    fetchHandler = wrapFetchOnError(this.options.fetch, this.options.onError);
+    fetchHandler = wrapFetch(this, fetchHandler);
 
     this.fetch = (request, info) => {
       Object.defineProperties(request, {

src/adapters/node.ts

@@ -9,7 +9,12 @@ import NodeHttp from "node:http";
 import NodeHttps from "node:https";
 import { sendNodeResponse } from "../_node-compat/send.ts";
 import { NodeRequest } from "../_node-compat/request.ts";
-import { fmtURL, resolvePort, resolveTLSOptions } from "../_utils.ts";
+import {
+  fmtURL,
+  resolvePort,
+  resolveTLSOptions,
+  wrapFetchOnError,
+} from "../_utils.ts";
 import { wrapFetch } from "../_plugin.ts";
 
 export {
@@ -53,7 +58,10 @@ class NodeServer implements Server {
   constructor(options: ServerOptions) {
     this.options = options;
 
-    const fetchHandler = wrapFetch(this, this.options.fetch);
+    let fetchHandler = this.options.fetch;
+    fetchHandler = wrapFetchOnError(this.options.fetch, this.options.onError);
+    fetchHandler = wrapFetch(this, fetchHandler);
+
     this.fetch = fetchHandler;
 
     const handler = (

src/types.ts

@@ -100,7 +100,7 @@ export interface ServerOptions {
    *
    * @note This handler will take precedence over runtime specific error handlers.
    */
-  onError?: (error: Error) => MaybePromise<Response>;
+  onError?: ErrorHandler;
 
   /**
    * Node.js server options.
@@ -256,6 +256,8 @@ export interface ServerRequest extends Request {
 
 export type FetchHandler = (request: Request) => Response | Promise<Response>;
 
+export type ErrorHandler = (error: Error) => Response | Promise<Response>;
+
 export type BunFetchHandler = (
   request: Request,
   server?: Bun.Server,