Add conditional exports to package.json

[lukescott]

I'm in the process of updating to Node 22 and I ran into an issue with the default export not working:

src/signature.tsx:25:18 - error TS2351: This expression is not constructable.
  Type 'typeof import("./node_modules/signature_pad/dist/types/signature_pad")' has no construct signatures.

25   this.pad = new SignaturePad(this.canvas, {

This PR fixes compatibility with TypeScript's "nodenext" module resolution. The "module" property is non-standard and not supported by node. The official way is "Conditional Exports":

https://nodejs.org/docs/latest-v22.x/api/packages.html#conditional-exports

This is needed for packages that support CommonJS and ESM where the "type" is omitted or set to "commonjs".

(Note: "require" could be omitted, but I was more explicit including both "require" and "default")

[UziTech]

Looks like it has a problem with the trailing comma in this line

[lukescott]

Fixed

[UziTech]

Thanks! 💯

[github-actions]

🎉 This PR is included in version 5.0.5 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[niklaas]

For posterity, this could be considered a breaking change, see https://nodejs.org/docs/latest-v22.x/api/packages.html#package-entry-points:

Existing packages introducing the "exports" field will prevent consumers of the package from using any entry points that are not defined, including the package.json (e.g. require('your-package/package.json')). This will likely be a breaking change.

To make the introduction of "exports" non-breaking, ensure that every previously supported entry point is exported. (...)

Our builds started failing and it took me a bit to figure out what's going on. In parts of our codebase we depended on signature_pad like this

require('signature_pad/dist/signature_pad.umd')

or

import SignaturePad from 'signature_pad/dist/signature_pad.umd'

which threw errors such as

  ERROR in ./<redacted>.js 142:0-47
  Module not found: Error: Package path ./dist/signature_pad.umd is not exported from package /<redacted>/node_modules/signature_pad (see exports field in /<redacted>/node_
modules/signature_pad/package.json)

This can be fixed by changing the above to

require('signature_pad')

and

import SignaturePad from 'signature_pad'

respectively.

[UziTech]

[BoussonKarel]

I think @niklaas' point is not the fact that we should not have added this, but that the semver was not respected.

v5 should have the old paths listed undert he exports key for backwards compatibility as specified in the node docs.

  "exports": {
    "import": "./dist/signature_pad.js",
    "require": "./dist/signature_pad.umd.js",
    "default": "./dist/signature_pad.umd.js",
    "./dist/signature_pad.js": "./dist/signature_pad.js",
    "./dist/signature_pad.min.js": "./dist/signature_pad.min.js",
    "./dist/signature_pad.umd.js": "./dist/signature_pad.umd.js",
    "./dist/signature_pad.umd.min.js": "./dist/signature_pad.umd.min.js",

  },

And then in 6.0.0 remove it

[UziTech]

Yes and my point is that if we need to change the major version every time it could break someone using it the way it wasn't intended to be used we would only ever release major versions.

[niklaas]

I wrote this hoping to help someone else if they come across the same issue in the future.

[lukescott]

The intention was to preserve backwards compatibility, and not knowing that import/require/defaults covered more than what "main" and (non-standard) "module" covered. If adding ./dist/ to the exports fixes the issue, a PR can certainly be opened and merged in to fix the breaking change. And I think that is worth doing, as more people may experience it over time.