From 59d83d7857ad57f9e25d6cbf76349c956560bf51 Mon Sep 17 00:00:00 2001
From: dab <dab@dmy.mailworks.org>
Date: Fri, 15 Aug 2025 14:39:24 +0000
Subject: [PATCH] better error handling (now wrapping user-defined functions
 with try/catch), better frontend logging (debug replaces info)

---
 backend/index.js  | 44 +++++++++++++++++++++++++++++++-------------
 frontend/index.js | 12 ++++++------
 2 files changed, 37 insertions(+), 19 deletions(-)

diff --git a/backend/index.js b/backend/index.js
index 8cedaa6..a48cfac 100644
--- a/backend/index.js
+++ b/backend/index.js
@@ -91,18 +91,31 @@ const start_server = function ({ context_meta, config, jsbuild_app_frontend, han
 				resp = new Response(get_siteroot_html({ page_title: config.page_title }), { status: 200, headers: { 'Content-Type': 'text/html' } })
 			}
 			else if (url.pathname === '/index.js') {
-				const str_js = await jsbuild_app_frontend()
-				resp = new Response(
-					await async_build_js_script(import.meta.dir + '/../frontend/index.js', {
-						define: {
-							JS_APP_FRONTEND: JSON.stringify(str_js),
+				let str_js
+				// wrap provided function in case it throws error
+				try {
+					str_js = await jsbuild_app_frontend()
+				}
+				catch (err) {
+					console.error(['error during JS build', err])
+				}
+				if (str_js !== undefined) {
+					resp = new Response(
+						await async_build_js_script(import.meta.dir + '/../frontend/index.js', {
+							define: {
+								JS_APP_FRONTEND: JSON.stringify(str_js),
+							}
+						}),
+						{
+							status: 200,
+							headers: { 'Content-Type': 'text/javascript' }
 						}
-					}),
-					{
-						status: 200, 
-						headers: { 'Content-Type': 'text/javascript' }
-					}
-				)
+					)
+				}
+				else {
+					// respond with generic HTTP error if JS build unsuccessful
+					resp = new Response(null, { status: 500 })
+				}
 			}
 			else if (url.pathname === '/ws') {
 				const uid = crypto.randomUUID()
@@ -159,7 +172,12 @@ const start_server = function ({ context_meta, config, jsbuild_app_frontend, han
 				console.info(['ws message', ws.data.uid, { size: m_bytes }])
 				if (handle_transport_bytes !== undefined) {
 					const transport_send_bytes = wrap_transport_sendbytes.bind(null, ws)
-					handle_transport_bytes({ transport_send_bytes }, message)
+					try {
+						handle_transport_bytes({ transport_send_bytes }, message)
+					}
+					catch (err) {
+						console.error(['error during handle_transport_bytes', err])
+					}
 				}
 				else {
 					console.warn('Unexpected: "handle_transport_bytes" not defined')
@@ -220,7 +238,7 @@ const async_run = async function ({
 		ws_map: new Map(),
 	}
 	const server = start_server({ context_meta, config: active_config, jsbuild_app_frontend, handle_transport_bytes })
-	console.info(server)
+	console.info(`framerock app now running at ${active_config.hostname}:${active_config.port}`)
 	process.on('SIGINT', async () => {
 		console.log('SIGINT intercepted')
 		close_active_ws_sessions({ context_meta })
diff --git a/frontend/index.js b/frontend/index.js
index a99b100..354482c 100644
--- a/frontend/index.js
+++ b/frontend/index.js
@@ -32,24 +32,24 @@ class FramerockUtils {
 	}
 	_setup_transport ({ on_open, on_close, on_message }) {
 		
-		console.info('SETUP TRANSPORT')
+		console.debug('SETUP TRANSPORT')
 		
 		this._ws = new WebSocket(`ws://${window.location.host}/ws`)
 		const ws = this._ws
 		ws.binaryType = 'arraybuffer'
 		
 		const func_on_open = () => {
-			console.info('WS OPEN')
+			console.debug('WS OPEN')
 			on_open && on_open()
 			return
 		}
 		const func_on_close = (event) => {
-			console.info('WS CLOSE')
+			console.debug('WS CLOSE')
 			on_close && on_close(event)
 			return
 		}
 		const func_on_message = (event) => {
-			console.info('WS MESSAGE', event)
+			console.debug('WS MESSAGE', event)
 			if (on_message !== undefined) {
 				on_message(event.data)
 			}
@@ -59,7 +59,7 @@ class FramerockUtils {
 			return
 		}
 		const func_on_error = () => {
-			console.info('WS ERROR')
+			console.debug('WS ERROR')
 			return
 		}
 		
@@ -73,7 +73,7 @@ class FramerockUtils {
 	}
 	_teardown_transport () {
 		
-		console.info('TEARDOWN TRANSPORT')
+		console.debug('TEARDOWN TRANSPORT')
 		
 		// NOTE: has no effect if ws already closed
 		this._ws.close()