fix: move package to ESM-Only and fix package exports

[userquin]

I cannot build date-picker-input on my local, once the corresponding dts generated, the subpackage types should be fixed: dist/date-picker-input/date-picker-input.d.ts missing.

Lit is using ESM-Only, you can check latest and 2.8.0 versions (v2.8.0 being used in 6 rc33):

• lit v3.1.1 types: https://arethetypeswrong.github.io/?p=lit%403.1.1
• lit v2.8.0 types: https://arethetypeswrong.github.io/?p=lit%402.8.0

Check screenshot in this comment: #222 (comment)

pnpm build && pnpm pack, go to https://arethetypeswrong.github.io/ and upload the tgz file: refresh page between builds.

EDIT: I can also include "packageManager": "pnpm@8.14.1" in the package.json

[codecov]

Codecov Report

Attention: 31 lines in your changes are missing coverage. Please review.

Comparison is base (3582b2c) 100.00% compared to head (e504a68) 92.82%.
Report is 8 commits behind head on main.

Files	Patch %	Lines
src/date-picker-input/date-picker-input.ts	82.50%	7 Missing and 7 partials ⚠️
src/year-grid/year-grid.ts	57.14%	9 Missing and 3 partials ⚠️
src/month-calendar/month-calendar.ts	90.00%	1 Missing and 3 partials ⚠️
src/date-picker/date-picker.ts	98.78%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##              main     #223      +/-   ##
===========================================
- Coverage   100.00%   92.82%   -7.18%     
===========================================
  Files           58       58              
  Lines         3305      711    -2594     
  Branches       238      155      -83     
===========================================
- Hits          3305      660    -2645     
- Misses           0       32      +32     
- Partials         0       19      +19     

Flag	Coverage Δ
unit_tests	92.82% <88.92%> (-7.18%)	⬇️
unit_tests_helpers	?

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[motss]

@userquin Could you please explain why is this required?

IIUC, exports is more than enough for TypeScript to read the corresponding types correctly from this article.

[userquin]

If your tsconfig file has compilerOptions.moduleResolution="node" TS will be using node10, there shoud be dts files in root folder and this package doesn't include them, types version entry will allow TS to detect dts files.

[motss]

TS will be using node10, there shoud be dts files in root folder and this package doesn't include them, types version entry will allow TS to detect dts files.

I don't remember that's how TypeScript works. and TypeScript does not enforce us to have a root dts file. CMIIW.

IIRC, it reads from types or typings in the package.json and you can see that I already it defined.

[userquin]

That's when importing app-datepicker, the problem when importing any app-datepicker subpackage.

[motss]

@userquin I looked into this and I need your help to clarify some things.

import { AppDatePicker } from 'app-datepicker/app-date-picker';

This import statement uses the exports field in package.json, which is only supported by node16 and later versions. To make this work in node10, we can use the typesVersions field to ship different types for different TypeScript versions.

IMHO, this does not feel right to me to use typesVersions for such use case because node10 users should avoid this kind of import and instead use relative paths to point to a specific file, like this:

// instead of doing this
// import { AppDatePicker } from 'app-datepicker/app-date-picker';

// node10 users should do this
import { AppDatePicker } from 'app-datepicker/dist/date-picker/app-date-picker.js';

WDYT?

[userquin]

You need support for node, node16(esm) and bundler.
The problem is in d.ts files, we will need to generate d.mts files for node16: when using relative imports inside a d.ts you need the extension and so you cannot reuse the same d.ts for node, node16 and bundler.
I'm going to try to use tsup and unbuild to generate proper d.ts and d.mts files.
In node16 you need to use .js extensions inside the d.ts (m.dts) when importing local modules (relative path).

[userquin]

Check this huge PR migrating to ESM-Only UnoCSS packages:
unocss/unocss#3380

[motss]

I kind of get it but this project does not support CommonJS/ require at all. It aims to ship only ESM files because it is supposed to run only on the browsers at the end of the day. Generating types just to support node10 and CommonJS is definitely out of the scope of the project unless it is a typing bug/ issue. TypeScript using moduleResolution=node can still reference the correct file and typing file without any issue as long as they use the relative file path. moduleResolution=node16|bundler and ESM are what this project supports and anything other than that is no-no. Hope it makes sense.

[userquin]

I didn't mention CJS at all ;). If you only support node16 and bundler you only need to fix typings.ts modules in this PR, and we can also remove types versions (node 10) from package.json file.

[motss]

IIUC, import is redundant as this package only supports ESM and default can do what we want it to do but I chose to keep it back then. I gues it's safe to remove those. Thanks for the removal.

[userquin]

This is about moving to ESM only, it is equivalent (you have type module)

[userquin]

You can use a bundler instead using tsc, for example you can use rollup, tsup or unbuild, this way you can write the build in the corresponding folders.

As an example, you can check lit (using rollup) package, the corresponding dts files in the root folder and subpackage exports with the corresponding folders (index.dts, decorators.d.ts, async-directive.d.ts, directives.d.ts... in root folder, decorators folder with the corresponding dts inside. This way when using Node/Node10, Node 16 or Bundler TS will not complain when resolving types: