Subpath imports in ESM mode about io-ts HOT 5 OPEN

FWIW, I got my own application to work after I did modifications summarized by this gist. The rabbithole went pretty deep.

I hope this will be useful for anyone stumbling upon this until ESM mode starts working properly for -ts packages.

Notice that my usecase might be different from yours and there might be additional setup for those exports fields mentioned in the gist to make things work.

from io-ts.

Here are the scripts that I use to produce the file layout described in suggested solution part (entrypoint is build:ci script):

{
  "scripts": {
    "build:ci": "yarn run clear-build-artifacts && yarn run compile-d-ts-files && yarn run tsc --outDir ./dist-esm && yarn run tsc --module CommonJS --outDir ./dist-cjs && yarn run format-output-files && yarn run fix-subpath-exports",
    "clear-build-artifacts": "rm -rf dist dist-ts dist-cjs dist-esm build",
    "compile-d-ts-files": "yarn run tsc --removeComments false --emitDeclarationOnly --declaration --declarationDir ./dist-ts && yarn run copy-d-ts-files && yarn run tsc:plain --project tsconfig.out.json",
    "copy-d-ts-files": "find ./src -mindepth 1 -maxdepth 1 -name '*.d.ts' -exec cp {} ./dist-ts +",
    "fix-subpath-exports": "mkdir <SUBPATH> && cp package.json.<SUBPATH> <SUBPATH>/package.json",
    "format-output-files": "find dist-ts -name '*.ts' -type f -exec sh -c \"echo '/* eslint-disable */\n/* eslint-enable prettier/prettier */'\"' | cat - $1 > $1.tmp && mv $1.tmp $1' -- {} \\; && eslint --no-eslintrc --config '.eslintrc.output.ts.cjs' --fix './dist-ts/**/*.ts' && eslint --no-eslintrc --config '.eslintrc.output.cjs' --fix 'dist-cjs/*js' 'dist-esm/*js'",
    "lint": "eslint ./src --ext .ts,.tsx",
    "tsc": "tsc --project tsconfig.build.json",
    "tsc:plain": "tsc",
  }
}

Notice that when dealing with large number of supported subpath exports, like all -ts packages seem to do, one probably wants fix-subpath-exports script to be more generic. One option would be to read subpaths from file, and then iterate each line with for loop, and create directory + copy/generate the stub package.json file.

Here are the TSConfig files used by script:

// tsconfig.out.json
{
  // TS config file for formatting the resulting .d.ts files (<project name>/dist-ts/**/*.d.ts) that end up in NPM package for typing information.
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "rootDir": "./dist-ts",
    "noEmit": true
  },
  "include": [
    "./dist-ts/**/*"
  ]
}

// tsconfig.build.json
{
  // TS config file to use to compile <project name>/src/**/*.ts files in CI.
  "extends": "./tsconfig.json",
  "compilerOptions": {
    // We don't want dangling // eslint-disable-xyz comments, as that will cause errors during formatting output .[m]js files.
    "removeComments": true
  },
}

And then the normal tsconfig.json file as your usual business. The motivation for these is that we would still have nicely auto-formatted (by ESLint, I personally use the Prettier plugin) .d.ts and .js files, instead of barely readable garbage produced by TS compiler and such.

P.S. No need to take this whole process into use. Just pick the parts which you think suits best to whatever approach you are using to build & publish packages. To be fair, I am happy with anything that makes subpath imports work in ESM mode. :)

from io-ts.

@gcanti I took a look at the package.json of this project, and I think I could contribute a PR related to this issue. Would you like me to do that, or are you handling this via some internal ideas/pipelines?

from io-ts.

I'm working on a new iteration of io-ts https://github.com/fp-ts/schema that will be soon included in the @effect org.
As soon as the new packages will be stable I will backport what's possible to the fp-ts ecosystem.
After that I will consider to release major versions of many packages, io-ts included, which will support esm.

from io-ts.

Oh, I see, really interesting to hear about the new iteration, as well as it being included to @effect umbrella! Will check it out for sure. 👍

from io-ts.