Function tryNext

packages/vite/hmr/client/index.ts:959–1008

()

	let idx = 0;

	const tryNext = () => {
		if (idx >= candidates.length) {
			console.warn('[hmr-client] All WS candidates failed:', candidates.join(', '));
			return;
		}
		const url = candidates[idx++];
		try {
			if (__NS_ENV_VERBOSE__) console.log('[hmr-client] Connecting to HMR WebSocket:', url);
			const sock = new WebSocket(url);
			hmrSocket = sock;
			setHttpOriginForVite(deriveHttpOrigin(url));

			let opened = false;
			const timeout = setTimeout(() => {
				if (!opened && sock.readyState !== WebSocket.OPEN) {
					try {
						sock.close();
					} catch {}
					if (VERBOSE) console.warn('[hmr-client] WS connect timeout, trying next…');
					tryNext();
				}
			}, 3500);

			sock.onopen = () => {
				opened = true;
				clearTimeout(timeout);
				VERBOSE && console.log('[hmr-client] Connected to HMR WebSocket');
			};
			sock.onmessage = handleHmrMessage;
			sock.onerror = (error: any) => {
				clearTimeout(timeout);
				console.warn('[hmr-client] WebSocket error:', (error && (error.message || error)) || error);
			};
			sock.onclose = (ev: any) => {
				clearTimeout(timeout);
				if (!opened) {
					// immediate failure during connect → try another candidate
					if (VERBOSE) console.warn('[hmr-client] WS close before open (code', ev?.code, '), trying next…');
					tryNext();
				} else {
					if (VERBOSE) console.log('[hmr-client] WebSocket closed (code', ev?.code, '), will reconnect…');
					// try to reconnect with full candidate list again
					setTimeout(connectHmr, 1000);
				}
			};
		} catch (e) {
			console.warn('[hmr-client] Failed to connect WebSocket', e);
			tryNext();
		}
	};

	tryNext();
}