HydraProvider.isConnected() silently ignores Greetings message — _connectionState never set to "CONNECTING"

[Crypto2099]

Summary

HydraProvider.isConnected() never resolves successfully because the onMessage callback has a guard that checks this._connectionState !== "CONNECTING", but _connectionState is never set to "CONNECTING". It starts as "IDLE" and the guard causes the Greetings message to be silently ignored, always resulting in a timeout.

Steps to reproduce the bug

Connect to any running Hydra node v1.2.0:

import { HydraProvider } from '@meshsdk/hydra';

const hp = new HydraProvider({
    url: 'http://localhost:4001',
    wsUrl: 'ws://localhost:4001',
});

// This always times out, even though the node sends a valid Greetings
const connected = await hp.isConnected(10000);

The WebSocket connects (logs "Hydra websocket connected"), and the Hydra node sends a valid Greetings message:

{
    "tag": "Greetings",
    "headStatus": "Idle",
    "hydraNodeVersion": "...",
    "me": {"vkey": "..."},
    "env": {...},
    "networkInfo": {...}
}

Actual Result

isConnected() always throws Error: Connection timed out: no Greetings from Hydra node.

Expected Result

Expect to see a message about the head being connected via the eventHandler.

SDK version

1.9.0-beta.99

Environment type

• Node.js
• Browser
• Browser Extension
• Other

Environment details

• @meshsdk/hydra: 1.9.0-beta.99
• Hydra node: ghcr.io/cardano-scaling/hydra-node:1.2.0
• Node.js: v22.22.2
• Network: Cardano preprod testnet

[Crypto2099]

Root Cause

In isConnected() (source), the onMessage callback has a guard:

this.onMessage((msg) => {
    if (this._connectionState !== "CONNECTING") return;  // ← BUG
    if (msg.tag === "Greetings") {
        finalize("CONNECTED", true);
        return;
    }
    // ...
});

_connectionState is initialized to "IDLE" and is never set to "CONNECTING" before this handler is registered. When the Greetings message arrives, the guard evaluates "IDLE" !== "CONNECTING" → true, so the callback returns early without processing the message. The timeout then fires and rejects with the misleading "no Greetings" error.

Suggested Fix

Add this._connectionState = "CONNECTING" before registering the onMessage handler:

this._connectingPromise = new Promise(async (resolve, reject) => {
    // ...
    try {
        await this.connect();
    } catch (err) {
        finalize("FAILED", false, err);
        return;
    }
    
    this._connectionState = "CONNECTING";  // ← ADD THIS
    
    timeout = setTimeout(() => {
        finalize("FAILED", false, new Error("Connection timed out: no Greetings from Hydra node"));
    }, timeoutMs);
    
    this.onMessage((msg) => {
        if (this._connectionState !== "CONNECTING") return;
        // ...
    });
});