Deprecation warning when using import

[rigwild]

When using import with esm using morgan, I get the following warning message :

morgan deprecated default format: use combined format node_modules\esm\esm.js:1:277757

This does not occur when using require. Example : https://repl.it/repls/SeagreenGrippingHexagon

On Morgan v1.9.1.

[dougwilson]

Thanks for the report. This should only display if you're trying to get the deprecated morgan.default property, though. I'll need to dig in to see what is going on.

[rigwild]

import loads default by default. This default property needs to be renamed. There's probably a workaround for this but I can't help.

[dougwilson]

So it will be renamed eventually, which is why it is deprecated.

[dhowe]

Same problem here. Is there anyway to get rid of the distracting 'deprecated' warning without forking and changing the source code?

[dougwilson]

I haven't yet investigated what changes can be made to this module to fix the deprecation warning for the import syntax, but the warnings can always be suppressed from printing, though node command line switch, event listener, environment variable. You can read more here about how the deprecation system works if that helps at all for the time being: https://www.npmjs.com/package/depd

[dhowe]

perhaps remove the deprecation warning until you have time to investigate further?

[dougwilson]

The deprecation warning was added almost 5 years ago and there was no issue until this issue. Perhaps if this issue was opened closer to when it was added reverting would be considered, but whatever has changed since then isn't this module.

[dhowe]

My guess is that people are simply using the 'import' style more now. The fix is just a comment (see this PR), but of course its your call...

[mbrowne]

Here is a fix that leaves the deprecation message in place: #207

Note that module.exports.default is still pointing to the default format function. I'm not sure if that might confuse any other tools that parse ES6 exports, but this at least prevents the deprecation warning from being erroneously shown when using esm.

[josemvcerqueira]

Quick fix is to pass "tiny" instead of dev to morgan.

[mbrowne]

@dougwilson I tried updating my app to use native ES modules now that they have landed in node (since node 13.2.0), but ran into some issues, so need to stick with esm for now. (It seems it will be a while before the ecosystem catches up with native ES modules to make adopting them a little more seamless.) So if you were to release a new major version of morgan that drops the deprecated default format (as you previously mentioned as a possibility), that would still be very helpful in the meantime.

[laurlas]

This will do the trick import * as morgan from 'morgan'

[ryhinchey]

To be clear, this issue is specific to using the esm package and not the import syntax in general.

Testing this with a basic import of import morgan from 'morgan' in node 12 or 13 does not produce the deprecation notice.

[chriscalo]

This will do the trick import * as morgan from 'morgan'

I was hopeful, but turns out this doesn't work 😕

[dougwilson]

I did some additional research today with the esm module and it looks like the issue is only with the import * syntax, using import morgan from 'morgan' not only did not produce the warning for me, but looking at the import syntax, that seems like the correct method to important this module. Can anyone who is using esm confirm this?

[mbrowne]

This is enough to cause the warning for me:

test.js:

import morgan from 'morgan'

node -r esm test.js

As discussed here, the issue is that morgan has an export called default that isn't actually the default export.

[ahmetbcakici]

same problem still!

[danieldare]

same problem yeah

[n2ptune]

same problem so far..

[hectorbus]

Same thing...

[craigcosmo]

I got this problem. any solutions ?

[n2ptune]

@craigcosmo It was solved by changing the import statement to require.

[craigcosmo]

yeah I tried that, and its fixed

[RMERCADOR98]

Hey guys!

When you call morgan just try to do this:

app.use(morgan("dev"));

It worked for me, the "dev" is cause i use "npm run dev" (you can change it on package.json, instead of using "start", to start the server, hope i could be helpfull :D

[mbrowne]

@RMERCADOR98 All that does is change to the formatting option named dev described in the readme, which is intended for development (so overly verbose and not ideal for production).

[mbrowne]

In other news, I am using Koa instead of Express in my latest server, so I used koa-morgan, so I'm not getting the warning anymore because the import is now indirect.

Obviously this won't help those who want to use Express or httpServer and so are using morgan directly - for that, the best workaround is still to just use require instead of import, until if/when the next version of morgan is eventually released.

[techieshark]

@mbrowne I can confirm that this prevents the deprecation warning:

const morgan = require('morgan');

... but in typescript, it seems I now lose type information on the file.

The following works, but only if tsconfig has compilerOptions.module = "CommonJS" rather than any of the 'ES...' module options (e.g. es6).

import morgan = require('morgan');

[rigwild]

@dougwilson Every new comment is repeating what has been said before. Maybe you should lock the conversation until resolved.

[daniyaniazi]

app.use(morgan("dev")); this does solve in my case

[prajwalmachado]

const morgan = require('morgan')
app.use(morgan('dev')) solves the issue

[mbrowne]

The require() workaround does the trick.

I've been a fan of the esm library, but there's now a totally different alternative that's worth considering: the new swc transpiler is so fast that it can easily replace esm (I haven't benchmarked it, but it seems to be just as fast if not faster.) And if you set your SWC target to a recent version of node like node 14 or 16, then it basically won't compile anything other than import/export statements, achieving the same goal (unless you're using very new JS features already supported by SWC but not by node...and that would actually be a good thing because it would allow you to use the latest features that you want without a lengthy compilation step, thanks to SWC's speed).

This is the config I used in my .swc file:

{
  "env": {
    "targets": {
      "node": "16"
    }
  },
  "module": {
    "type": "commonjs"
  },
  "jsc": {
    "externalHelpers": true
  },
  "sourceMaps": "inline"
}

Make sure to install @swc/helpers as a production dependency if you use "externalHelpers": true like I did.

[SilvinPradhan]

you could just use const morgan = require("morgan"); instead of using import