Named exports don’t work with Node.js ESM support

[calebmer]

When you try to import {createMemoryHistory} from 'history' in a Node.js .mjs file you get an error that createMemoryHistory is not a named export.

It appears that this is because the only main field supported by Node.js history exposes is "main" which points to a CommonJS module with exports that can’t be inferred by cjs-module-lexer. I think "exports" is the new field Node.js uses to lookup compatible ES Modules.

history/packages/history/package.json

Lines 8 to 11 in 8117ab2

	"main": "main.js",
	"module": "index.js",
	"types": "index.d.ts",
	"unpkg": "umd/history.production.min.js",

[zvictor]

I don't understand how the package.json has been designed.
How is it possible that there is no "type": "module", no "exports", no .mjs extension, but files like browser.js contain ESM code?
How is the node client supposed to know that that file is ESM and not CJS?

The way package.json currently is, index.js is the only file that could contain ESM code because of the "main" entry.
Did I get anything wrong here?

---

Lines like this one

import history from 'history/browser'

Throw error like these:

error - ~/myApp/node_modules/.pnpm/history@5.3.0/node_modules/history/browser.js:397
export { browser as default };
^^^^^^

SyntaxError: Unexpected token 'export'
    at Object.compileFunction (node:vm:360:18)
    at wrapSafe (node:internal/modules/cjs/loader:1049:15)
    at Module._compile (node:internal/modules/cjs/loader:1084:27)
    at Module._extensions..js (node:internal/modules/cjs/loader:1174:10)
    at Module.load (node:internal/modules/cjs/loader:998:32)
    at Module._load (node:internal/modules/cjs/loader:839:12)
    at Module.require (node:internal/modules/cjs/loader:1022:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at history/browser (~/myApp/apps/jobs/.next/server/pages/index.js:2144:18)
    at __webpack_require__ (~/myApp/apps/jobs/.next/server/webpack-runtime.js:33:43) {
  page: '/'
}