DeprecationWarning: Use of deprecated folder mapping "./" in the "exports" field

[marcbachmann]

Node 16 logs a deprecation warning that the syntax for the exports declaration in the package.json changed from "./": "./" to "./*": "./*" .

(node:97520) [DEP0148] DeprecationWarning: Use of deprecated folder mapping "./" in the "exports" field module resolution of the package at /Users/marcbachmann/Development/livingdocsIO/livingdocs-server/master/node_modules/@elastic/elasticsearch7/package.json.
Update this package.json to use a subpath pattern like "./*".
    at emitFolderMapDeprecation (node:internal/modules/esm/resolve:69:11)
    at packageExportsResolve (node:internal/modules/esm/resolve:542:7)
    at resolveExports (node:internal/modules/cjs/loader:477:36)
    at Function.Module._findPath (node:internal/modules/cjs/loader:517:31)
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:926:27)

Node 12 doesn't support this new declaration and therefore this would be a breaking change.
How can we get rid of the deprecation warning for newer environments without breaking support for older versions?

[stale]

We understand that this might be important for you, but this issue has been automatically marked as stale because it has not had recent activity either from our end or yours.
It will be closed if no further activity occurs, please write a comment if you would like to keep this going.

Note: in the past months we have built a new client, that has just landed in master. If you want to open an issue or a pr for the legacy client, you should do that in https://github.com/elastic/elasticsearch-js-legacy

[marcbachmann]

To not do a breaking change, could we expose a separate package.json with the correct annotation in a subdirectory to get rid of the deprecation message?

[tony]

I am getting this on node v16.4.0 with @elastic/[email protected]

[tony]

same issue with other projects: postcss/postcss#1455, microsoft/playwright#6248, microsoft/tslib#135 (comment)

[tony]

My workaround was NODE_OPTIONS="--no-deprecation"

e. g.

• env NODE_OPTIONS="--no-deprecation" yarn start
• env NODE_OPTIONS="--no-deprecation" node ./myscript.js
• in package.json "scripts":

  "scripts": {
    "start": "cross-env NODE_OPTIONS=\"--no-deprecation\" yarn develop"
  }

  if you dont' use cross-env, replace cross-env -> env

[trentm]

@delvedor In Node.js nightly build v17.0.0-nightly20210923c7da13c7c4 (per nodejs/node#40121) this will be a runtime exception:

% ~/tmp/node-v17.0.0-nightly20210923c7da13c7c4-darwin-x64/bin/node
Welcome to Node.js v17.0.0-nightly20210923c7da13c7c4.
Type ".help" for more information.
> require('@elastic/elasticsearch/package.json').version
Uncaught:
Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './package.json' is not defined by "exports" in /Users/trentm/el/apm-agent-nodejs/node_modules/@elastic/elasticsearch/package.json
    at __node_internal_captureLargerStackTrace (node:internal/errors:464:5)
    at new NodeError (node:internal/errors:371:5)
    at throwExportsNotFound (node:internal/modules/esm/resolve:416:9)
    at packageExportsResolve (node:internal/modules/esm/resolve:669:3)
    at resolveExports (node:internal/modules/cjs/loader:482:36)
    at Function.Module._findPath (node:internal/modules/cjs/loader:522:31)
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:919:27)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:999:19)
    at require (node:internal/modules/cjs/helpers:102:18) {
  code: 'ERR_PACKAGE_PATH_NOT_EXPORTED'
}

This change "fixes" that for me:

--- node_modules/@elastic/elasticsearch/package.json.orig	2021-09-27 10:51:30.000000000 -0700
+++ node_modules/@elastic/elasticsearch/package.json	2021-09-27 10:51:36.000000000 -0700
@@ -75,7 +75,7 @@
       "require": "./index.js",
       "import": "./index.mjs"
     },
-    "./": "./"
+    "./*": "./*"
   },
   "homepage": "http://www.elastic.co/guide/en/elasticsearch/client/javascript-api/current/index.html",
   "keywords": [

[marcbachmann]

a solution to this could be to list all the files explicitly

[trentm]

Note that I've found a workaround for my use case. With https://github.com/elastic/apm-agent-nodejs/pull/2351/files#diff-4044438594f145ca4e5b9920e844237cce63dd56744a23e3f263456e6a9f7d35R37-R64 I'm avoiding using require('@elastic/elasticsearch/package.json').

I don't know if others had use cases to directly import other parts of this package.

[marcbachmann]

Oh, exactly my use case. Thanks

[delvedor]

Closed in #1593.