[BUG] Node.js 16 results in DeprecationWarning: Use of deprecated folder mapping "./" in the "exports" field with file import

[zdm]

Current exports syntax is not compatible with node 15.

(node:12200) [DEP0148] DeprecationWarning: Use of deprecated folder mapping "./" in the "exports" field module resolution of the package at C:\Users\zdm\.node_modules\playwright-chromium\package.json.
Update this package.json to use a subpath pattern like "./*".

You need to update to the new rules or remove this section.

New rules should looks like this:

"exports": {
    ".": {
      "import": "./index.mjs",
      "require": "./index.js"
    },
    "./*": "./*.js"
  },

[pavelfeldman]

Where do you see this message and this line? Could you provide the steps to reproduce? It does not complain on node/15.13 + npm/7.7.6 for me.

[zdm]

try this code:

require( "playwright-chromium/lib/client/page" );

I need to add custom methods to the Page class prototype, so I need to require client/page directly.
In any case current folders export synax is already deprecated and you need to update it.

[pavelfeldman]

require( "playwright-chromium/lib/client/page" );

Works for me on the node / npm versions i mentioned above. Are there any steps I can follow to reproduce this?

[zdm]

You need to perform require from the external script or package.

[pavelfeldman]

You need to perform require from the external script or package.

That's what I did. Node changed its mind on the deprecation:

nodejs/node#35747
nodejs/node#36859

What is your Node 15 version? Is it recent?

[zdm]

here is the link to the specification, where this api marked as deprecated.
https://nodejs.org/api/packages.html#packages_subpath_folder_mappings

[zdm]

my node - 5.13.0

[zdm]

sorry, 15.13.0 ))

[pavelfeldman]

I'm on macOS, v15.13.0, I have a single dependency in my node_modules, which is playwright. My index file in the root folder is:

require( "playwright/lib/client/page" );

and I can run it ok. If I add a non-default --pending-deprecation flag I get your warning, but I don't get it without it. Are you by any chance running it with pending deprecations flag?

[pavelfeldman]

As https://nodejs.org/api/deprecations.html#deprecations_dep0148_folder_mappings_in_exports_trailing states,

Without --pending-deprecation, runtime warnings occur only for exports resolutions not in node_modules.
This means there will not be deprecation warnings for "exports" in dependencies.

Are you using playwright outside of the node_modules?

[zdm]

adAhh, sorry.
Node was updated today to 15.13.0 and this warning had gone.
It was present on node 15.12.0.

[zdm]

Yes, i installed playwright globally.

[pavelfeldman]

Globally is still via node_modules, so we are good. Ok then, closing as not an issue!