ConnectionException: Process with ID 83312 exited before connecting.

[CallumVass]

Hi,

I'm trying to use this library but I keep facing this exception when using version 7 of this library, if I downgrade to 6.3.1 it works fine?

For the avoidance of doubt, I can run node just fine from command line so its definitely on my PATH. I am using .NET 8 (I've tried in .NET 6 and 7 too) and Node 20:

node -v
v20.5.1

dotnet --version
8.0.100

Here is my log output from a small repro:

using Jering.Javascript.NodeJS;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

var services = new ServiceCollection();
services.AddLogging(loggingBuilder =>
{
    loggingBuilder.SetMinimumLevel(LogLevel.Debug);
    loggingBuilder.AddConsole();
});
services.AddNodeJS();
StaticNodeJSService.SetServices(services);

// Invoke
string javascriptModule = @"
module.exports = (callback, x, y) => {  // Module must export a function that takes a callback as its first parameter
    var result = x + y; // Your javascript logic
    callback(null /* If an error occurred, provide an error object or message */, result); // Call the callback when you're done.
}";
int result = await StaticNodeJSService.InvokeFromStringAsync<int>(javascriptModule, args: new object[] { 3, 5 });
Console.WriteLine(result); // 8

Log:

dbug: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      Waiting on process connection semaphore, processID: 81620, thread ID: 1, thread is ThreadPool thread : False.
fail: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      The command line is too long.

warn: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      An attempt to connect to NodeJS failed. Retries remaining: 2.
      Exception:
        Jering.Javascript.NodeJS.ConnectionException: Process with ID 81620 exited before connecting.
         at Jering.Javascript.NodeJS.OutOfProcessNodeJSService.CreateNewProcessAndConnectAsync()
dbug: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      Waiting on process connection semaphore, processID: 74272, thread ID: 11, thread is ThreadPool thread : True.
fail: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      The command line is too long.

warn: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      An attempt to connect to NodeJS failed. Retries remaining: 1.
      Exception:
        Jering.Javascript.NodeJS.ConnectionException: Process with ID 74272 exited before connecting.
         at Jering.Javascript.NodeJS.OutOfProcessNodeJSService.CreateNewProcessAndConnectAsync()
dbug: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      Waiting on process connection semaphore, processID: 83312, thread ID: 11, thread is ThreadPool thread : True.
fail: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      The command line is too long.

Unhandled exception. Jering.Javascript.NodeJS.ConnectionException: Process with ID 83312 exited before connecting.
   at Jering.Javascript.NodeJS.OutOfProcessNodeJSService.CreateNewProcessAndConnectAsync()
   at Jering.Javascript.NodeJS.OutOfProcessNodeJSService.ConnectIfNotConnectedAsync(CancellationToken cancellationToken)
   at Jering.Javascript.NodeJS.OutOfProcessNodeJSService.TryInvokeCoreAsync[T](InvocationRequest invocationRequest, CancellationToken cancellationToken)
   at Jering.Javascript.NodeJS.OutOfProcessNodeJSService.InvokeFromStringAsync[T](String moduleString, String cacheIdentifier, String exportName, Object[] args, CancellationToken cancellationToken)

[aKzenT]

I think the real error is "The command line is too long." which is printed before the process exits (or never even starts). Since the library passes an internal script on the command line, the command line will be quite long already, maybe on your system it gets too long

What OS are you running on? Is the path name to your application and to the node executable very long?

[CallumVass]

Hiya, thanks for the reply - I'm on Windows 11 and the project isn't nested very deep: C:\Dev\JsSample\JsSample.csproj

But it works fine with 6.3.1, as soon as I upgrade to version 7 thats when the error occurs

[ZeldaIV]

I am on MacOS and I am also experiencing this. Tested both static and DI-approach, which not surprisingly, fails in the same way.

[aKzenT]

@CallumVass what about the path to the node executable?

@ZeldaIV do you also see the "command line too long" error in the log output?

[CallumVass]

@aKzenT Likewise, my node executable isn't very deep either: C:\Program Files\nodejs\node.exe

[CallumVass]

Something happened between 7.0.0-beta.4 and 7.0.0-beta.5 which is causing the issue. It works all the way up to installing beta 5, then I get that error. If I go back to beta 4 it works fine.

[JeremyTCD]

@CallumVass Thanks for the details. We did make changes from beta 4 to 5 that affected script length:

• Moved from webpack to vite. Webpack was minifying the script, vite should be as well?
• Changed script from cjs to esm

PR: #173

We need to check how the length of the script changed after these changes.

If it got longer we should shorten it to no longer than before, perhaps more aggressive minification with Vite (if possible) or manual code simplification.

@aKzenT would you like to handle this issue?

[JeremyTCD]

In beta 4 we were passing the configuration to the webpack script. Webpack was automatically minifying when mode was "release":

Javascript.NodeJS/src/NodeJS/Jering.Javascript.NodeJS.csproj

Lines 100 to 101 in 41f70f4

	<Yarn WorkingDirectory=".\Javascript" Command="run build --env mode=$(Configuration) --env entry=./Servers/OutOfProcess/Http/Http11Server.ts" />
	<Yarn WorkingDirectory=".\Javascript" Command="run build --env mode=$(Configuration) --env entry=./Servers/OutOfProcess/Http/Http20Server.ts" />

Javascript.NodeJS/src/NodeJS/Javascript/webpack.config.js

Lines 1 to 27 in 41f70f4

	const path = require('path');
	module.exports = env => {
	let mode = env.mode.toLowerCase() === 'release' ? 'production' : 'development'; // Default to development, production mode minifies scripts
	console.log(`Mode: ${mode}.`);
	return {
	mode: mode,
	target: 'node',
	resolve: {
	extensions: ['.ts', '.js']
	},
	module: {
	rules: [
	{ test: /\.ts$/, loader: 'ts-loader' }
	]
	},
	entry: env.entry,
	output: {
	hashFunction: 'xxhash64',
	libraryTarget: 'commonjs2',
	path: path.join(__dirname, 'bin', env.mode),
	filename: path.basename(env.entry, path.extname(env.entry)) + '.js'
	}
	};
	};

In beta 5 we are no longer minifying:

Javascript.NodeJS/src/NodeJS/Jering.Javascript.NodeJS.csproj

Lines 99 to 100 in 5999180

	<Yarn WorkingDirectory=".\Javascript" Command="run build --ssr ./Servers/OutOfProcess/Http/Http11Server.ts --outDir bin/$(Configuration)" />
	<Yarn WorkingDirectory=".\Javascript" Command="run build --ssr ./Servers/OutOfProcess/Http/Http20Server.ts --outDir bin/$(Configuration)" />

Javascript.NodeJS/src/NodeJS/Javascript/vite.config.ts

Lines 1 to 8 in 5999180

	import { defineConfig } from "vite";
	export default defineConfig({
	build: {
	emptyOutDir: false,
	ssr: true,
	},
	});

I've verified that:

import { defineConfig } from "vite";

export default defineConfig({
    build: {
        minify: true,
        emptyOutDir: false,
        ssr: true,
    },
});

as suggested by @CallumVass minifies adequately:

• Vite minified bundle: 4515 characters
• Webpack minified bundle: 4717 characters

We just need to pass the configuration to vite.config. I'm not familiar with Vite though, @CallumVass would you like to create a pull request with the necessary changes?

[CallumVass]

I've minified it locally using minify: true but it still doesn't work, here is what I see in the console:

dbug: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      Waiting on process connection semaphore, processID: 112264, thread ID: 9, thread is ThreadPool thread : True.
fail: Jering.Javascript.NodeJS.HttpNodeJSService[0]
      Starting inspector on 127.0.0.1:9229 failed: address already in use
      file:///C:/Dev/csharp/JavascriptTest/JavascriptTest/[eval1]:1
      import T from"module";import*as E from"http2";import*as d from"path";import*as I from"stream";var f=(e=>(e[e.Cache=0]="Cache",e[e.File=1]="File",e[e.String=2]="String",e[e.Stream=3]="Stream",e))(f||{});function N(){co
nst e=P(process.argv);S(process.stdout),S(process.stderr),k(parseInt(e.parentPid),!0,1e3);const t=process.cwd(),o=b(t);return O(t),[e,t,o]}function a(e,t){const o=typeof t=="string";e.statusCode=500,e.end(JSON.stringify({er
rorMessage:o?t:t.message,errorStack:o?null:t.stack}))}function p(e){return e.cacheIdentifier==null?`"${e.moduleSource.substring(0,25)}..."`:e.cacheIdentifier}function b(e){const t=[d.join(e,"node_modules")];let o=e,i;for(;(
o=d.dirname(o))!==i;)t.push(d.join(o,"node_modules")),i=o;return t}function P(e){let t=null;const o={};return e.forEach(i=>{if(i.indexOf("--")===0){const c=i.substring(2);o[c]=void 0,t=c}else t!==null&&(o[t]=i,t=null)}),o}f
unction k(e,t,o){setInterval(()=>{w(e)||(console.log(`[Node.js HTTP server] Parent process (pid: ${e}) exited. Exiting this process...`),process.exit())},o),t&&process.on("SIGINT",()=>{console.log("[Node.js HTTP server] Rec
eived SIGINT. Waiting for .NET process to exit...")})}function w(e){try{return process.kill(e,0),!0}catch(t){if(t.code==="EPERM")throw new Error(`Attempted to check whether process ${e} was running, but got a permissions er
ror.`);return!1}}function O(e){function t(c,n){try{return i.apply(this,arguments)}catch(s){if(s.message.startsWith("EPERM")&&typeof o=="string"&&o.startsWith(c)&&s.stack.indexOf("Object.realpathSync ")>=0)return i.call(this
,e,n);throw s}}let o=null,i=null;if(/^win/.test(process.platform))try{o=d._makeLong(e);const c=process.binding("fs");i=c.lstat,typeof i=="function"&&(c.lstat=t)}catch{}}function S(e){const t=e.write;e.write=function(o){typeof o=="string"&&(arguments[0]=o.slice(0,o.length-1)+`\0
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
      SyntaxError: Unexpected end of input
          at DefaultModuleLoader.evalInstance (node:internal/modules/esm/loader:104:22)
          at new ModuleJob (node:internal/modules/esm/module_job:63:26)
          at DefaultModuleLoader.eval (node:internal/modules/esm/loader:115:17)
          at node:internal/process/execution:51:55
          at loadESM (node:internal/process/esm_loader:40:13)
          at evalModule (node:internal/process/execution:51:28)
          at node:internal/main/eval_string:29:3

      Node.js v20.5.1

Looking at the generated script, it doesnt match what is being passed above, the last few characters: +`\0
Are at the end of the first line in the minified script, so it seems to be missing the rest of it?

[JeremyTCD]

Odd that it is getting truncated. After changing minify to true, how are you running it locally?

Could you try running the test suite? It passes on my windows 11 machine with minify set to true.

[CallumVass]

@JeremyTCD - Yeah I get the same error in tests, using Windows 11 also:

[xUnit.net 00:00:00.92]         SyntaxError: Unexpected end of input

Its the same as above, the script seems truncated. It looks like vite isnt minifying across a single line like the webpack one was doing and that is causing an issue somewhere

[JeremyTCD]

The library escapes the script before starting the node process:

Javascript.NodeJS/src/NodeJS/NodeJSServiceImplementations/OutOfProcess/NodeJSProcessFactory.cs

Lines 105 to 158 in 5999180

	internal static string EscapeCommandLineArg(string arg)
	{
	var stringBuilder = new StringBuilder();
	int slashSequenceLength = 0;
	for (int i = 0; i < arg.Length; i++)
	{
	char currentChar = arg[i];
	if (currentChar == '\\')
	{
	slashSequenceLength++;
	// If the last character in the argument is \, it must be escaped, together with any \ that immediately preceed it.
	// This prevents situations like: SomeExecutable.exe "SomeArg\", where the quote meant to demarcate the end of the
	// argument gets escaped.
	if (i == arg.Length - 1)
	{
	for (int j = 0; j < slashSequenceLength; j++)
	{
	stringBuilder.
	Append('\\').
	Append('\\');
	}
	}
	}
	else if (currentChar == '"')
	{
	// Every \ or sequence of \ that preceed a " must be escaped.
	for (int j = 0; j < slashSequenceLength; j++)
	{
	stringBuilder.
	Append('\\').
	Append('\\');
	}
	slashSequenceLength = 0;
	stringBuilder.
	Append('\\').
	Append('"');
	}
	else
	{
	for (int j = 0; j < slashSequenceLength; j++)
	{
	stringBuilder.Append('\\');
	}
	slashSequenceLength = 0;
	stringBuilder.Append(currentChar);
	}
	}
	return stringBuilder.ToString();
	}

This is where the process start info is created:

Javascript.NodeJS/src/NodeJS/NodeJSServiceImplementations/OutOfProcess/NodeJSProcessFactory.cs

Lines 49 to 59 in 5999180

	var startInfo = new ProcessStartInfo(_nodeJSProcessOptions.ExecutablePath!) // ConfigureNodeJSProcessOptions sets ExecutablePath to "node" if user specified value is null, whitespace or an empty string
	{
	Arguments = $"{_nodeJSProcessOptions.NodeAndV8Options} --input-type=module -e \"{nodeServerScript}\" -- --parentPid {currentProcessPid} --port {_nodeJSProcessOptions.Port}",
	UseShellExecute = false,
	RedirectStandardInput = true,
	RedirectStandardOutput = true,
	RedirectStandardError = true,
	WorkingDirectory = _nodeJSProcessOptions.ProjectPath,
	// If this option isn't set to true, in certain situations, e.g. in windows forms projects, a Node.js console window pops up when scripts are invoked.
	CreateNoWindow = true
	};

Could you place breakpoints and take a closer look at nodeServerScript?

I can't reproduce the issue on my machine so it's definitely a system-specific problem:

2023-12-03.17-23-00.mp4

[CallumVass]

This is what is passed as arguments to the process via startInfo:

--inspect-brk --input-type=module -e "import T from\"module\";import*as I from\"http\";import*as d from\"path\";import*as E from\"stream\";var f=(e=>(e[e.Cache=0]=\"Cache\",e[e.File=1]=\"File\",e[e.String=2]=\"String\",e[e.Stream=3]=\"Stream\",e))(f||{});function b(){const e=P(process.argv);S(process.stdout),S(process.stderr),$(parseInt(e.parentPid),!0,1e3);const t=process.cwd(),n=N(t);return w(t),[e,t,n]}function c(e,t){const n=typeof t==\"string\";e.statusCode=500,e.end(JSON.stringify({errorMessage:n?t:t.message,errorStack:n?null:t.stack}))}function p(e){return e.cacheIdentifier==null?`\"${e.moduleSource.substring(0,25)}...\"`:e.cacheIdentifier}function N(e){const t=[d.join(e,\"node_modules\")];let n=e,i;for(;(n=d.dirname(n))!==i;)t.push(d.join(n,\"node_modules\")),i=n;return t}function P(e){let t=null;const n={};return e.forEach(i=>{if(i.indexOf(\"--\")===0){const l=i.substring(2);n[l]=void 0,t=l}else t!==null&&(n[t]=i,t=null)}),n}function $(e,t,n){setInterval(()=>{k(e)||(console.log(`[Node.js HTTP server] Parent process (pid: ${e}) exited. Exiting this process...`),process.exit())},n),t&&process.on(\"SIGINT\",()=>{console.log(\"[Node.js HTTP server] Received SIGINT. Waiting for .NET process to exit...\")})}function k(e){try{return process.kill(e,0),!0}catch(t){if(t.code===\"EPERM\")throw new Error(`Attempted to check whether process ${e} was running, but got a permissions error.`);return!1}}function w(e){function t(l,r){try{return i.apply(this,arguments)}catch(s){if(s.message.startsWith(\"EPERM\")&&typeof n==\"string\"&&n.startsWith(l)&&s.stack.indexOf(\"Object.realpathSync \")>=0)return i.call(this,e,r);throw s}}let n=null,i=null;if(/^win/.test(process.platform))try{n=d._makeLong(e);const l=process.binding(\"fs\");i=l.lstat,typeof i==\"function\"&&(l.lstat=t)}catch{}}function S(e){const t=e.write;e.write=function(n){typeof n==\"string\"&&(arguments[0]=n.slice(0,n.length-1)+`\0
`),t.apply(this,arguments)}}const m=T,[O,j,C]=b();J();function J(){const e=I.createServer(L);e.setTimeout(0),e.keepAliveTimeout=0,e.headersTimeout=2147483647,e.on(\"timeout\",_),e.on(\"clientError\",R),e.listen(parseInt(O.port),\"localhost\",()=>{let t=e.address();console.log(`[Jering.Javascript.NodeJS: HttpVersion - HTTP/1.1 Listening on IP - ${t.address} Port - ${t.port}]`)})}function L(e,t){const n=[];e.on(\"data\",i=>n.push(i)).on(\"end\",async()=>{var i;try{const l=Buffer.concat(n).toString();let r;if(e.headers[\"content-type\"]===\"multipart/mixed\"){const o=l.split(\"--Uiw6+hXl3k+5ia0cUYGhjA==\");r=JSON.parse(o[0]),r.moduleSource=o[1]}else r=JSON.parse(l);let s;if(r.moduleSourceType===f.Cache){const o=m._cache[r.moduleSource];if(o==null){t.statusCode=404,t.end();return}s=o.exports}else if(r.moduleSourceType===f.Stream||r.moduleSourceType===f.String){if(r.cacheIdentifier!=null){const o=m._cache[r.cacheIdentifier];o!=null&&(s=o.exports)}if(s==null){const o=new m(\"\",null);o.paths=C,o._compile(r.moduleSource,\"anonymous\"),r.cacheIdentifier!=null&&(m._cache[r.cacheIdentifier]=o),s=o.exports}}else if(r.moduleSourceType===f.File)s=await import(\"file:///\"+d.resolve(j,r.moduleSource).replaceAll(\"\\\\\",\"/\"));else{c(t,`Invalid module source type: ${r.moduleSourceType}.`);return}if(s==null||typeof s==\"object\"&&Object.keys(s).length===0){c(t,`The module ${p(r)} has no exports. Ensure that the module assigns a function or an object containing functions to module.exports.`);return}let a;if(r.exportName!=null){if(a=s[r.exportName]??((i=s.default)==null?void 0:i[r.exportName]),a==null){let o=Object.keys(s).join(\", \");c(t,`The module ${p(r)} has no export named ${r.exportName}. Available exports are: ${o}`);return}if(typeof a!=\"function\"){c(t,`The export named ${r.exportName} from module ${p(r)} is not a function.`);return}}else if(typeof s==\"function\")a=s;else if(typeof s.default==\"function\")a=s.default;else{c(t,`The module ${p(r)} does not export a function.`);return}let g=!1;const y=(o,u,h)=>{if(!g&&(g=!0,o!=null&&c(t,o),!(h!=null&&h(t))))if(u instanceof E.Readable)u.pipe(t);else if(typeof u==\"string\")t.end(u);else{let x;try{x=JSON.stringify(u)}catch(v){c(t,v);return}t.end(x)}};if(a.constructor.name===\"AsyncFunction\")y(null,await a.apply(null,r.args));else{const o=[y];a.apply(null,o.concat(r.args))}}catch(l){c(t,l)}})}function R(e,t){let n=JSON.stringify({errorMessage:e.message,errorStack:e.stack}),i=`HTTP/1.1 500 Internal Server Error\r
Content-Length: ${Buffer.byteLength(n,\"utf8\")}\r
Content-Type: text/html\r
\r
${n}`;t.end(i)}function _(e){console.log(`[Node.js HTTP server] Ignoring unexpected socket timeout for address ${e.remoteAddress}, port ${e.remotePort}`)}
" -- --parentPid 132476 --port 0

It looks like its going over multiple lines so I suspect thats the issue? The \r seems to be causing issues I think

[JeremyTCD]

Yes it looks like line endings are the issue. Managed to repro with the script you pasted:

VM88 [eval1]:1 Uncaught SyntaxError: Unexpected end of input
    at ModuleLoader.evalInstance (VM83 loader:203:22)
    at new ModuleJob (VM87 module_job:65:26)
    at ModuleLoader.eval (VM83 loader:215:17)
    at node:internal/process/execution:56:55
    at loadESM (VM82 esm_loader:34:13)
    at evalModule (node:internal/process/execution:56:28)
    at VM80 eval_string:30:3

When you open Http11Server.js, are your line endings crlf or lf?