Handle Rejections functionality is not working

[betalb]

• winston version?
  • winston@2
  • winston@3
• node -v outputs: v10.16.0
• Operating System? macOS
• Language? ES6/7

What is the problem?

In both below cases nodejs will print default unhandled rejection error

1. setting handleRejections flag to true during transport creation is not working
2. calling logger.rejections.handle(transport) is not working

What do you expect to happen instead?

Winston should intercept unhandled rejection and log it

Other information

1st problem is due to not released change in winston-transport package: winstonjs/winston-transport#47
2nd problem is due to typo in _addHandler method of lib/winston/rejection-handler.js:

winston/lib/winston/rejection-handler.js

Line 153 in 15c9653

handler.handleExceptions = true;

This line should be ADDED handler.handleRejections = true

There is one important thing: without handleExceptions, handleRejections won't log anything, due to below check: https://github.com/winstonjs/winston-transport/blob/46db8f3c8cd8b106ade8d7e04a191ee388683d60/index.js#L70

Testcases

Fails

const { createLogger, transports } = require('winston');

const logger = createLogger({
  transports: new transports.Console({
    level: 'info',
    handleRejections: true,
  }),
});

logger.info('Start');

new Promise((resolve, reject) => {
  process.nextTick(() => {
    reject(new Error('Rejected'));
  });
}).then(() => {});

Succeeds (Trick is in using Object.assign on transport instance)

const { createLogger, transports } = require('winston');

const logger = createLogger({
  transports: Object.assign(
    new transports.Console({
      handleExceptions: true,
    }),
    {
      handleRejections: true,
    },
  ),
});

logger.info('Start');

new Promise((resolve, reject) => {
  process.nextTick(() => {
    reject(new Error('Rejected'));
  });
}).then(() => {});

[mitjans]

Any progress on this?

[mrehanabbasi]

Any update on this? The documentation of winston@3 on github shows the rejections section but it is not available on the npm package page.

[ab-pm]

I think this is fixed with #1779 and can be closed?

[betalb]

Probably, and winston-transport was released 2 months ago with required change too. I will re-test with latest version

[betalb]

Looks like issue is fixed, but only if handleExceptions is also set to true

[halfalicious]

Still not working

[rizwan-hanif]

it looks like on winston@3.3.3 setting handleRejections on transport will write it on handleExceptions transport.
e.g. following will write promise rejection logs to ex.logs

winston.exceptions.handle(
  new winston.transports.File({ filename: "ex.logs" })
);
winston.add(
  new winston.transports.File({
    filename: "logging.log",
    handleRejections: true,
  })
);

and following will write promise rejections along with exceptions to same transport logging.log

winston.add(
 new winston.transports.File({
   filename: "logging.log",
   handleRejections: true,
   handleExceptions: true
 })
);

[quickdraw6906]

Sadly, the neat workaround offered by @rizwan-hanif does not work for transports.Console

let defaultTransport =
  new LOG.transports.Console({
    level: logLevel,
    handleExceptions: true,
    handleRejections: true,
  });

Argument of type '{ level: string; handleExceptions: true; handleRejections: boolean; }' is not assignable to parameter of type 'ConsoleTransportOptions'.
Object literal may only specify known properties, but 'handleRejections' does not exist in type 'ConsoleTransportOptions'. Did you mean to write 'handleExceptions'?

[rizwan-hanif]

@quickdraw6906 issue is of winston-transport TypeScript types syncing reported here 44.
for TypeScript you might have to get latest winston-transport version with above issue resolved (unfortunately not available yet) or you can try this

let consoleTransportOptions={
    level: 'info',
    handleExceptions: true,
    handleRejections: true,
  }
let defaultTransport =
  new LOG.transports.Console(consoleTransportOptions);

[quickdraw6906]

Thanks so much!