fix: type EventSource error callbacks as Event

test/eventsource/eventsource-request-status-error.js

@@ -31,3 +31,19 @@ describe('EventSource - status error', () => {
     })
   })
 })
+
+test('EventSource error handlers receive a plain Event', async (t) => {
+  const server = http.createServer((req, res) => res.writeHead(404).end())
+  t.after(() => server.close())
+  await once(server.listen(0, '127.0.0.1'), 'listening')
+
+  const source = new EventSource(`http://127.0.0.1:${server.address().port}`)
+  t.after(() => source.close())
+  let callbackEvent
+  source.onerror = (event) => { callbackEvent = event }
+  const [event] = await once(source, 'error')
+
+  t.assert.strictEqual(event.constructor, Event)
+  t.assert.strictEqual(callbackEvent, event)
+  t.assert.strictEqual('message' in event, false)
+})

test/types/event-source-d.ts

@@ -1,5 +1,5 @@
 import { URL } from 'node:url'
-import { expectType, expectAssignable } from 'tsd'
+import { expectType, expectAssignable, expectError } from 'tsd'
 
 import { Agent, EventSource, EventSourceInit, Dispatcher } from '../../'
 
@@ -23,3 +23,13 @@ expectAssignable<EventSourceInit>({ withCredentials: true })
 expectAssignable<EventSourceInit>({})
 
 expectType<Agent>(new Agent({ eventSource: { maxEventSize: 1024 } }))
+
+eventSource.onerror = (event) => {
+  expectType<Event>(event)
+  expectError(event.message)
+}
+
+eventSource.addEventListener('error', (event) => {
+  expectType<Event>(event)
+  expectError(event.message)
+})

types/eventsource.d.ts

@@ -1,4 +1,4 @@
-import { MessageEvent, ErrorEvent } from './websocket'
+import { MessageEvent } from './websocket'
 import Dispatcher from './dispatcher'
 
 import {
@@ -8,7 +8,7 @@ import {
 } from './patch'
 
 interface EventSourceEventMap {
-  error: ErrorEvent
+  error: Event
   message: MessageEvent
   open: Event
 }
@@ -18,7 +18,7 @@ interface EventSource extends EventTarget {
   readonly CLOSED: 2
   readonly CONNECTING: 0
   readonly OPEN: 1
-  onerror: ((this: EventSource, ev: ErrorEvent) => any) | null
+  onerror: ((this: EventSource, ev: Event) => any) | null
   onmessage: ((this: EventSource, ev: MessageEvent) => any) | null
   onopen: ((this: EventSource, ev: Event) => any) | null
   readonly readyState: 0 | 1 | 2