SyntaxError: Unexpected end of JSON input returns statuscode 500 instead of 400

I’m submitting a…

[ ] Regression 
[x] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

curl -X POST "http://localhost:3000/login" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"email\": \"[e-mail]\", \"password\": \"secret\""

{
  "statusCode": 500,
  "message": "Internal server error"
}

Expected behavior

curl -X POST "http://localhost:3000/login" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"email\": \"[e-mail]\", \"password\": \"secret\""

{
  "statusCode": 400,
  "message": "Bad request"
}

Or even better:

{
  "statusCode": 400,
  "message": "SyntaxError: Unexpected end of JSON input"
}

Minimal reproduction of the problem with instructions

Boilerplate nestjs application, any post endpoint, any invalid json POST.

What is the motivation / use case for changing the behavior?

If I enable my global AnyExceptionFilter and log the exception, I get a 400 statuscode.

{ SyntaxError: Unexpected end of JSON input
    at JSON.parse (<anonymous>)
    at parse (/Users/name/Downloads/avgAPI/node_modules/body-parser/lib/types/json.js:88:17)
    at /Users/name/Downloads/avgAPI/node_modules/body-parser/lib/read.js:116:18
    at invokeCallback (/Users/name/Downloads/avgAPI/node_modules/raw-body/index.js:262:16)
    at done (/Users/name/Downloads/avgAPI/node_modules/raw-body/index.js:251:7)
    at IncomingMessage.onEnd (/Users/name/Downloads/avgAPI/node_modules/raw-body/index.js:307:7)
    at emitNone (events.js:106:13)
    at IncomingMessage.emit (events.js:208:7)
    at endReadableNT (_stream_readable.js:1056:12)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
  body: '{\n  "email": "[e-mail]",\n  "password": "secret"',
  status: 400,
  statusCode: 400 }

Environment

Nest version: 4.6.3

 
For Tooling issues:
- Node version: 8.9.1  
- Platform:  Mac 

Others:

[kamilmysliwiec]

Fixed in v4.6.4 🙂

[lo78cn]

@chanlito I disagree 😃

Internal Error 500
The server encountered an unexpected condition which prevented it from fulfilling the request.

It is not an unexpected error.

Bad request 400
The request had bad syntax or was inherently impossible to be satisfied.

Makes more sense in my opinion.