✘ [ERROR] A hanging Promise was canceled. This happens when the worker runtime is waiting for a Promise from JavaScript to resolve, but has detected that the Promise cannot possibly ever resolve because all code and events related to the Promise's I/O context have already finished.


[wrangler:err] SyntaxError: Unexpected end of JSON input

✘ [ERROR] A hanging Promise was canceled. This happens when the worker runtime is waiting for a Promise from JavaScript to resolve, but has detected that the Promise cannot possibly ever resolve because all code and events related to the Promise's I/O context have already finished.


[wrangler:err] SyntaxError: Unexpected end of JSON input

const connections: WebSocket[] = []

export default {
    fetch: (req) => {
        const url = new URL(req.url)
        if (url.pathname === "/ws") {
            const upgradeHeader = req.headers.get("Upgrade")
            if (!upgradeHeader || upgradeHeader !== "websocket") {
                return new Response("Expected Upgrade: websocket", { status: 426 })
            }
            const webSocketPair = new WebSocketPair()
            const [client, server] = Object.values(webSocketPair)
            server.accept()
            connections.push(server)
            connections.forEach((ws) => ws.send("new connection!"))
            // logic to remove on "close" event
            return new Response(null, {
                status: 101,
                webSocket: client,
            })
        }
        return new Response(`
<script>
const ws = new WebSocket("ws://localhost:8787/ws")
ws.onmessage = (e) => {
    console.log("data", e.data)
}
ws.onopen = () => {
    console.log("open")
    ws.send("hi")
}
</script>
            `, {
            headers: {
                "Content-Type": "text/html; charset=utf-8",
            }
        })
    },
} satisfies ExportedHandler<{}>

const connections: WebSocket[] = []

export default {
    fetch: (req) => {
        const url = new URL(req.url)
        if (url.pathname === "/ws") {
            const upgradeHeader = req.headers.get("Upgrade")
            if (!upgradeHeader || upgradeHeader !== "websocket") {
                return new Response("Expected Upgrade: websocket", { status: 426 })
            }
            const webSocketPair = new WebSocketPair()
            const [client, server] = Object.values(webSocketPair)
            server.accept()
            connections.push(server)
            connections.forEach((ws) => ws.send("new connection!"))
            // logic to remove on "close" event
            return new Response(null, {
                status: 101,
                webSocket: client,
            })
        }
        return new Response(`
<script>
const ws = new WebSocket("ws://localhost:8787/ws")
ws.onmessage = (e) => {
    console.log("data", e.data)
}
ws.onopen = () => {
    console.log("open")
    ws.send("hi")
}
</script>
            `, {
            headers: {
                "Content-Type": "text/html; charset=utf-8",
            }
        })
    },
} satisfies ExportedHandler<{}>