parseDate: false is not respected for WebSocket messages

[qimingweng]

Description

When creating a treaty client with parseDate: false, HTTP responses correctly leave ISO date strings as strings. However, WebSocket messages still auto-convert ISO date strings to Date objects — the parseDate option is not forwarded to the WS message parser.

Reproduction

import { Elysia } from "elysia";
import { treaty } from "@elysiajs/eden";

const app = new Elysia()
  .get("/api/time", () => {
    return { time: "2026-04-09T12:00:00.000Z" };
  })
  .ws("/ws", {
    open(ws) {
      ws.send({ time: "2026-04-09T12:00:00.000Z" });
    },
    message() {},
  })
  .listen(0);

const port = app.server!.port;
const client = treaty<typeof app>(`http://localhost:\${port}`, {
  parseDate: false,
});

// HTTP: parseDate:false works
const { data } = await client.api.time.get();
console.log(typeof data!.time); // "string" ✓

// WS: parseDate:false is ignored
const ws = client.ws.subscribe();
ws.on("message", ({ data: wsData }) => {
  console.log(typeof wsData.time); // "object" ✗ (Date)
  console.log(wsData.time instanceof Date); // true ✗
  ws.close();
  app.stop();
});

Expected behavior

typeof wsData.time should be "string" when parseDate: false is set.

Actual behavior

wsData.time is a Date object — the parseDate: false config is ignored for WebSocket messages.

Root cause

Looking at the compiled source, the WS message deserializer (S function in chunk-I5KHAGLL.mjs) receives a config parameter r, and checks r?.parseDate === false. However the treaty client does not pass its config through when calling this function for WS messages.

Environment

• @elysiajs/eden: 1.4.9
• elysia: 1.4.27
• bun: 1.3.11