bodyParse error suppression - node.js

I'm currently using bodyParser with Express to accept JSON requests. Whenever I pass in an incorrectly formed JSON object it returns a nasty error via the endpoint and logs it to the console as well. The following is the error:
SyntaxError: Unexpected string
at Object.parse (native)
at parse (/Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/lib/types/json.js:88:17)
at /Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/lib/read.js:108:18
at done (/Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/node_modules/raw-body/index.js:239:14)
at IncomingMessage.onEnd (/Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/node_modules/raw-body/index.js:285:7)
at IncomingMessage.g (events.js:199:16)
at IncomingMessage.emit (events.js:104:17)
at _stream_readable.js:908:16
at process._tickCallback (node.js:355:11)
SyntaxError: Unexpected string
at Object.parse (native)
at parse (/Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/lib/types/json.js:88:17)
at /Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/lib/read.js:108:18
at done (/Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/node_modules/raw-body/index.js:239:14)
at IncomingMessage.onEnd (/Users/ddibiase-mbp/Documents/Projects/theride_api/node_modules/body-parser/node_modules/raw-body/index.js:285:7)
at IncomingMessage.g (events.js:199:16)
at IncomingMessage.emit (events.js:104:17)
at _stream_readable.js:908:16
at process._tickCallback (node.js:355:11)
I'm wondering how I can suppress the error or patch this completely. I've investigated the error but can't find any specific recommendations for patching it.

It's common to declare an error handler with Express:
app.use(function(err, req, res, next) {
...
return res.sendStatus(500);
});
This will also catch errors thrown in middleware like body-parser.

Related

How to parse error parameter in request callback?

I'm deliberately triggering an error in a stored procedure under certain conditions which I want to catch in my Node.js API which uses the Tedious package.
Code Snippet from API:
let request = new Request(sql, (err)=>{
if (err) {
sqlerr = err;
console.log(typeof(err));
console.log("**RQ-ERROR**", err);
}
});
In the callback of the "Request" object above there is an "err" parameter. The "typeof()" returns "object"; however, when I dump it to the console it looks like this:
**RQ-ERROR** { RequestError: Duplicate entry for specified period
at RequestError (C:\inetpub\wwwroot\PersonnelApps\kudosapi\node_modules\tedious\lib\errors.js:32:12)
at Parser.tokenStreamParser.on.token (C:\inetpub\wwwroot\PersonnelApps\kudosapi\node_modules\tedious\lib\connection.js:723:34)
at emitOne (events.js:96:13)
at Parser.emit (events.js:188:7)
at Parser.parser.on.token (C:\inetpub\wwwroot\PersonnelApps\kudosapi\node_modules\tedious\lib\token\token-stream-parser.js:27:14)
at emitOne (events.js:96:13)
at Parser.emit (events.js:188:7)
at addChunk (C:\inetpub\wwwroot\PersonnelApps\kudosapi\node_modules\readable-stream\lib\_stream_readable.js:297:12)
at readableAddChunk (C:\inetpub\wwwroot\PersonnelApps\kudosapi\node_modules\readable-stream\lib\_stream_readable.js:279:11)
at Parser.Readable.push (C:\inetpub\wwwroot\PersonnelApps\kudosapi\node_modules\readable-stream\lib\_stream_readable.js:240:10)
message: 'Duplicate entry for specified period',
code: 'EREQUEST',
number: 50000,
state: 1,
class: 16,
serverName: 'PERSODG2LNN52\\SQLEXPRESS',
procName: 'CreateStatusReport',
lineNumber: 44 }
This almost looks like a JavaScript object but, as you can see, the "RequestError" data isn't quoted nor is there a comma after the text "240:10)" just before the "message" member. I'm not sure if this is a bug in TDS or if I'm just missing something but I cannot access any of the members as it is. I'd have to convert it to a string and parse it which is fine but isn't very elegant.
Suggestions?
as you can see, the "RequestError" data isn't quoted nor is there a comma after the text "240:10)"
These are artifacts of the console logging out the error message. You can try it out for yourself with something like the following:
$ node
> console.log(new Error('this is an error object!'));
Error: this is an error object!
at repl:1:13
at Script.runInThisContext (vm.js:119:20)
at REPLServer.defaultEval (repl.js:332:29)
at bound (domain.js:395:14)
at REPLServer.runBound [as eval] (domain.js:408:12)
at REPLServer.onLine (repl.js:639:10)
at REPLServer.emit (events.js:194:15)
at REPLServer.EventEmitter.emit (domain.js:441:20)
at REPLServer.Interface._onLine (readline.js:290:10)
at REPLServer.Interface._line (readline.js:638:8)
I'm not exactly sure what the desired outcome of this question is, but try inspecting the err.message property rather than using the typeof operator.

node connect-timeout: how to suppress "ServiceUnavailableError: Response timeout" log message

I'm using the connect-timeout module. When the timeout fires, it seems to dump the following error message to the console:
ServiceUnavailableError: Response timeout
at IncomingMessage.<anonymous> (/app/node_modules/connect-timeout/index.js:75:8)
at emitOne (events.js:96:13)
at IncomingMessage.emit (events.js:188:7)
at Timeout._onTimeout (/app/node_modules/connect-timeout/index.js:48:11)
at ontimeout (timers.js:365:14)
at tryOnTimeout (timers.js:237:5)
at Timer.listOnTimeout (timers.js:207:5)
How do I suppress these log messages? I don't particularly want to see them, because the timeout firing is not really an indicator that there is a problem... it's just doing its job. And this is especially because I can add my own error handling middleware to express that can pick and choose what (if anything) to do with the error.
You need to catch this from express, the code should look like:
function errorHandler (err, req, res, next) {
console.log("Oops")
}
app.use(errorHandler)
For more info:
https://expressjs.com/en/guide/error-handling.html

Neo4j's NPM component blows up without error

I'm using the thingdom/node-neo4j module like this:
var neo = require('neo4j');
var db = new new.GraphDatabase(...);
but when I call the cypher method with some invalid script, instead of returning an error (allowing me to handle it), it blows up:
db.cypher('// invalid cypher script', (err, res) => {
if (err) console.log('ERROR: ' + err);
console.log(res);
})
what I get is a stack trace that looks like this:
/Users/ekkis/dev/test/inc/node_modules/neo4j/lib-new/errors.js:20
Error.captureStackTrace(this, this.constructor);
^
TypeError: Error.captureStackTrace is not a function
at ClientError.Error [as constructor] (/Users/ekkis/dev/test/inc/node_modules/neo4j/lib-new/errors.js:20:13)
at new ClientError (/Users/ekkis/dev/test/inc/node_modules/neo4j/lib-new/errors.js:81:48)
at Function.__dirname.Error.Error._fromObject (/Users/ekkis/dev/test/inc/node_modules/neo4j/lib-new/errors.js:70:14)
at /Users/ekkis/dev/test/inc/node_modules/neo4j/lib-new/GraphDatabase.js:302:25
at Request._callback (/Users/ekkis/dev/test/inc/node_modules/neo4j/lib-new/GraphDatabase.js:92:20)
at Request.self.callback (/Users/ekkis/dev/test/inc/node_modules/request/request.js:187:22)
at emitTwo (events.js:106:13)
at Request.emit (events.js:191:7)
at Request. (/Users/ekkis/dev/test/inc/node_modules/request/request.js:969:12)
at emitNone (events.js:91:20)
at IncomingMessage.emit (events.js:185:7)
at endReadableNT (_stream_readable.js:974:12)
at _combinedTickCallback (internal/process/next_tick.js:74:11)
at process._tickCallback (internal/process/next_tick.js:98:9)
I'm using node v7.3.0 and posted an issue with the maintainer here: https://github.com/thingdom/node-neo4j/issues/214 but so far no solution. is anyone else running into this? any solutions?

ForEachLine() in node.js

Referring to slide no 35 in ppt on slideshare
When I run this code
var server = my_http.createServer();
server.on("request", function(request,response){
var chunks = [];
output = fs.createWriteStream("./output");
request.on("data",function(chunk){
chunks = forEachLine(chunks.concat(chunk),function(line){
output.write(parseInt(line,10)*2);
output.write("\n");
})
});
request.on("end",function(){
response.writeHeader(200,{"Content-Type":"plain/text"})
response.end("OK\n");
output.end()
server.close()
})
});
server.listen("8080");
I get error as
chunks = forEachLine(chunks.concat(chunk),function(line){
^
ReferenceError: forEachLine is not defined
Of course I unserstand that I need to include some library but when I googled this I found nothing . Since I am complete newbie to this I have absolutely no idea how to resolve it.
Any suggestions will be appreciable.
EDIT
Using the suggested answer I am getting error as
events.js:72
throw er; // Unhandled 'error' event
^
TypeError: Invalid non-string/buffer chunk
at validChunk (_stream_writable.js:150:14)
at WriteStream.Writable.write (_stream_writable.js:179:12)
at /var/www/html/experimentation/nodejs/first.js:18:20
at Array.forEach (native)
at forEachLine (/var/www/html/experimentation/nodejs/first.js:8:60)
at IncomingMessage.<anonymous> (/var/www/html/experimentation/nodejs/first.js:17:18)
at IncomingMessage.EventEmitter.emit (events.js:95:17)
at IncomingMessage.<anonymous> (_stream_readable.js:736:14)
at IncomingMessage.EventEmitter.emit (events.js:92:17)
at emitReadable_ (_stream_readable.js:408:10)
Thanks
See proxy_stream.js
function forEachLine(chunks, callback) {
var buffer = chunks.join("")
buffer.substr(0, buffer.lastIndexOf("\n")).split("\n").forEach(callback)
return buffer.substr(buffer.lastIndexOf("\n") + 1).split("\n")
}
The link to the repo was on the first slide.
EDIT BY LET's CODE FOR ERROR MESSAGE
Came to know the actual issue now .
I was using nod v0.10 and it is buggy in getting the streams so I was getting the error. Downgraded to v0.8 and same code is working perfect .

Nodejs TypeError: Cannot read property 'chId' of undefined

I have Omegle-clone chat service. In stress my nodejs (over 150 users) crash with error "TypeError: Cannot read property 'chId' of undefined" .
/home/kotka/randomi.fi/beta/varaserver2/channel.js:67
f = this.channels[e].chId;
^
TypeError: Cannot read property 'chId' of undefined
at Channel.joinChannel (/home/kotka/randomi.fi/beta/varaserver2/channel.js:67:23)
at Session.createSession (/home/kotka/randomi.fi/beta/varaserver2/session.js:21:23)
at /home/kotka/randomi.fi/beta/varaserver2/path.js:1:268
at Server.<anonymous> (/home/kotka/randomi.fi/beta/varaserver2/fu.js:43:3)
at Server.emit (events.js:70:17)
at HTTPParser.onIncoming (http.js:1610:12)
at HTTPParser.parserOnHeadersComplete [as onHeadersComplete] (http.js:91:29)
at Socket.ondata (http.js:1506:22)
at TCP.onread (net.js:374:27)
What is problem and how I can fix it?
channel.js source
try capturing the exception with
process.on('uncaughtException', function(err) {
console.error(err.stack);
});
This just means that this.channels[e] is undefined and does not have a chId attribute.

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