Node esm support

While I was testing to add an export map I found the following problem.

e.g. if we add this to minisearch

  "exports": {
    ".": {
      "types": "./dist/types/index.d.ts",
      "require": "./dist/umd/index.js",
      "default": "./dist/es/index.js"
    }
  },

and then try to use it in node

// package.json
  "type": "module"
// test.js
import MiniSearch from 'minisearch';

// execute
node test.js

we get the following error

node test.js
(node:65561) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
/www/testmini/node_modules/minisearch/dist/es/index.js:1436
export default MiniSearch;
^^^^^^

SyntaxError: Unexpected token 'export'

which is correct as we try to import the file dist/es/index.js but the package minisearch is define as a require package… e.g. it has an implicit "type": "commonjs",. e.g. all *.js files are treated as common js

Solutions

1. add type: "module" to package.json to minisearch so that *.js files are treated as modules (and export the commonjs version as *.cjs files)
2. export the module version as *.mjs (which is kinda strange for a browser but still works)

What do you think?

[daKmoR]

you can probably support “all” the node versions if you want

something like this

"type": "module",
// node <12
"main": "./dist/cjs/index.cjs"
// node 12+
"exports": {
   // ts 4.7+
   "types": "./dist/types/index.d.ts",
   "require": "./dist/cjs/index.cjs",
   "default": "./dist/esm/index.js"
}
// ts < 4.7
"types": "./dist/types/index.d.ts",

and then I guess you would also have a separate umd for CDNs?

[lucaong]

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