Circular reference warnings in the main library export

[alexp1917]

Please tell us about your environment:

• winston version?
  • winston@2
  • winston@3
• node -v outputs: v15.8.0
• Operating System? Ubuntu: Linux $HOSTNAME 5.8.0-41-generic #46~20.04.1-Ubuntu SMP Mon Jan 18 17:52:23 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
• Language? Javascript

What is the problem?

starting up an interactive shell prints lots of warnings after requiring the winston library, and then simply typing out its name to see its exports

Example output

$ node --trace-warnings
Welcome to Node.js v15.8.0.
Type ".help" for more information.
> var winston = require('winston')
undefined
> win(node:46170) Warning: Accessing non-existent property 'Symbol(nodejs.util.inspect.custom)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)[Getter], Stream: [Getter] }, config: { cli: [Object], npm: [Object], syslog: [Object], addColors: [Function (anon...
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatValue (node:internal/util/inspect:746:30)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at Object.inspect (node:internal/util/inspect:336:10)
(node:46170) Warning: Accessing non-existent property 'constructor' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.getOwnPropertyDescriptor (node:internal/modules/cjs/loader:719:5)
    at getOwnPropertyDescriptor (<anonymous>)
    at getConstructorName (node:internal/util/inspect:548:24)
    at formatRaw (node:internal/util/inspect:797:23)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.toStringTag)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:803:18)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.iterator)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:827:12)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
ston  (node:46170) Warning: Accessing non-existent property 'Symbol(nodejs.util.inspect.custom)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)[Getter], Stream: [Getter] }, config: { cli: [Object], npm: [Object], syslog: [Object], addColors: [Function (anon...
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatValue (node:internal/util/inspect:746:30)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at Object.inspect (node:internal/util/inspect:336:10)
(node:46170) Warning: Accessing non-existent property 'constructor' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.getOwnPropertyDescriptor (node:internal/modules/cjs/loader:719:5)
    at getOwnPropertyDescriptor (<anonymous>)
    at getConstructorName (node:internal/util/inspect:548:24)
    at formatRaw (node:internal/util/inspect:797:23)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.toStringTag)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:803:18)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.iterator)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:827:12)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
ton    (node:46170) Warning: Accessing non-existent property 'Symbol(nodejs.util.inspect.custom)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)[Getter], Stream: [Getter] }, config: { cli: [Object], npm: [Object], syslog: [Object], addColors: [Function (anon...
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatValue (node:internal/util/inspect:746:30)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at Object.inspect (node:internal/util/inspect:336:10)
(node:46170) Warning: Accessing non-existent property 'constructor' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.getOwnPropertyDescriptor (node:internal/modules/cjs/loader:719:5)
    at getOwnPropertyDescriptor (<anonymous>)
    at getConstructorName (node:internal/util/inspect:548:24)
    at formatRaw (node:internal/util/inspect:797:23)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.toStringTag)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:803:18)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.iterator)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:827:12)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
on      (node:46170) Warning: Accessing non-existent property 'Symbol(nodejs.util.inspect.custom)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)[Getter], Stream: [Getter] }, config: { cli: [Object], npm: [Object], syslog: [Object], addColors: [Function (anon...
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatValue (node:internal/util/inspect:746:30)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at Object.inspect (node:internal/util/inspect:336:10)
(node:46170) Warning: Accessing non-existent property 'constructor' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.getOwnPropertyDescriptor (node:internal/modules/cjs/loader:719:5)
    at getOwnPropertyDescriptor (<anonymous>)
    at getConstructorName (node:internal/util/inspect:548:24)
    at formatRaw (node:internal/util/inspect:797:23)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.toStringTag)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:803:18)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.iterator)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:827:12)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
n        (node:46170) Warning: Accessing non-existent property 'Symbol(nodejs.util.inspect.custom)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)[Getter], Stream: [Getter] }, config: { cli: [Object], npm: [Object], syslog: [Object], addColors: [Function (anon...
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatValue (node:internal/util/inspect:746:30)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at Object.inspect (node:internal/util/inspect:336:10)
(node:46170) Warning: Accessing non-existent property 'constructor' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.getOwnPropertyDescriptor (node:internal/modules/cjs/loader:719:5)
    at getOwnPropertyDescriptor (<anonymous>)
    at getConstructorName (node:internal/util/inspect:548:24)
    at formatRaw (node:internal/util/inspect:797:23)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.toStringTag)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:803:18)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
(node:46170) Warning: Accessing non-existent property 'Symbol(Symbol.iterator)' of module exports inside circular dependency
    at emitCircularRequireWarning (node:internal/modules/cjs/loader:698:11)
    at Object.get (node:internal/modules/cjs/loader:712:5)
    at formatRaw (node:internal/util/inspect:827:12)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
    at formatValue (node:internal/util/inspect:787:10)
    at formatProperty (node:internal/util/inspect:1675:11)
    at formatRaw (node:internal/util/inspect:1000:9)
.v  at formersion
'3.3.3'

What do you expect to happen instead?

I expect the output to not contain warnings, like so:

$ node
Welcome to Node.js v15.8.0.
Type ".help" for more information.
> var lodash = require('lodash')
undefined
> lodash
<ref *1> [Function: lodash] {
  templateSettings: {
    escape: /<%-([\s\S]+?)%>/g,
    evaluate: /<%([\s\S]+?)%>/g,
    interpolate: /<%=([\s\S]+?)%>/g,
    variable: '',
    imports: { _: [Circular *1] }
  },
  after: [Function: after],
  ary: [Function: ary],
  assign: [Function (anonymous)],
  assignIn: [Function (anonymous)],
  assignInWith: [Function (anonymous)],
  assignWith: [Function (anonymous)],
  at: [Function (anonymous)],

instead this is the output:

$ node
Welcome to Node.js v15.8.0.
Type ".help" for more information.
> var winston = require('winston')
undefined
> win(node:46398) Warning: Accessing non-existent property 'Symbol(nodejs.util.inspect.custom)' of module exports inside circular dependency
(Use `node --trace-warnings ...` to show where the warning was created)tp: [Getter], Stream: [Getter] }, config: { cli: [Object], npm: [Object], syslog: [Object], addColors: [Function (anon...
(node:46398) Warning: Accessing non-existent property 'constructor' of module exports inside circular dependency
(node:46398) Warning: Accessing non-existent property 'Symbol(Symbol.toStringTag)' of module exports inside circular dependency
(node:46398) Warning: Accessing non-existent property 'Symbol(Symbol.iterator)' of module exports inside circular dependency

[td-krzysiek]

Confirmed with node v14.17.6

[rambo-panda]

Confirmed with node v20.10.0

[DABH]

If anyone wants to help figure out where this is coming from, PR would be gladly welcomed (maintainers are stretched thin). I'm happy to review any potential fix though.

[Mr0grog]

Took a look at things here this morning and the circular reference causing the problem is actually in winston-transport, where TransportStream (the export of the main module there) has a .LegacyTransportStream property that is a subclass of TransportStream.

It should probably be fixed there, although it can be worked around here by requiring winston-transport before any other part of the package requires winston-transport/legacy (due to an interesting quirk of how this particular circular dependency works, the problems cleans itself up automatically if you require the main export of the winston-transport module first).

Also worth noting: this issue is also currently breaking the winston.Transport.LegacyTransportStream object:

// Broken:
const winston = require('winston');
new winston.Transport.LegacyTransportStream({ transport: { log(info, cb) { cb(); }, on() {} }});
// Logs:
// new winston.Transport.LegacyTransportStream({ transport: { log(info, cb) { cb(); }, on() {} }});
// ^
//
// TypeError: winston.Transport.LegacyTransportStream is not a constructor
//     at Object.<anonymous> (/Users/rbrackett/Dev/winston/testme.js:2:1)
//     at Module._compile (node:internal/modules/cjs/loader:1241:14)
//     at Module._extensions..js (node:internal/modules/cjs/loader:1295:10)
//     at Module.load (node:internal/modules/cjs/loader:1091:32)
//     at Module._load (node:internal/modules/cjs/loader:938:12)
//     at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:83:12)
//     at node:internal/main/run_main_module:23:47

// But this works fine when referencing legacy transport directly:
const LegacyTransportStream = require('winston-transport/legacy');
new LegacyTransportStream({ transport: { log(info, cb) { cb(); }, on() {} }});

[Mr0grog]

Filed a PR to fix it upstream in winston-transport: winstonjs/winston-transport#207

Once that’s merged and released, then this package will need to update its dependency on winston-transport to whatever the new version number there is.

[DABH]

Thanks @Mr0grog for the help on this one! I merged the winston-transport PR and did a release there, so a fix for this should go out in the next winston release.

[Mr0grog]

No problem! Do I need to do a PR to update the minimum version of winston-transport in package.json here, or are you already on that/not worried about it?

[DABH]

Dependabot should automatically open a PR tomorrow but if you want to beat the bot to it, go for it :)

[Mr0grog]

Oh, if it's configured to update the minimums, then I'll just leave it to Dependabot. Nothing more to do here. 👍

[Mr0grog]

Looks like the relevant update happened in #2422 and was released in v3.12.0. I set up a project to test it out and this seems to be fixed, so I think the issue can be closed, @DABH (or whoever has permissions)!