bug: fails to load config in ESM project

[elijaholmos]

In any project where "type": "module" exists in the package.json, this package crashes when trying to load a config file. The error that appears is similar to:

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: C:\coding-work\cosmiconfig\cosmiconfigts-repro\amazing.config.ts
require() of ES modules is not supported.
require() of C:\coding-work\cosmiconfig\cosmiconfigts-repro\amazing.config.ts from C:\coding-work\cosmiconfig\cosmiconfigts-repro\node_modules\.pnpm\cosmiconfig-typescript-loader@4.2.0_whq6te2zcgakt4fgsicma7l33e\node_modules\cosmiconfig-typescript-loader\dist\cjs\index.js is an ES module file as it is a .ts file whose nearest parent package.json contains "type": "module" which defines all .ts files in that package scope as ES modules.
Instead change the requiring code to use import(), or remove "type": "module" from C:\coding-work\cosmiconfig\cosmiconfigts-repro\package.json.

The cause of the issue appears to be with the require statement here:

cosmiconfig-typescript-loader/lib/loader.ts

Lines 12 to 14 in 37a3004

	// cosmiconfig requires the transpiled configuration to be CJS
	tsNodeInstance.compile(content, path);
	const result = require(path);

I can provide a sample repro repo if requested.

related issue: dotansimha/graphql-code-generator-community#225

[Codex-]

I'm very keen to support import and remove the cjs limitation, however this requires that cosmiconfig supports esm too. Currently they only emit cjs: https://github.com/davidtheclark/cosmiconfig/blob/main/package.json#L95

[geisterfurz007]

For visibility, this is the related upstream PR cosmiconfig/cosmiconfig#283

[tal-rofe]

Is there any workaround?

[Codex-]

Is there any workaround?

For not being able to load esm? Can't do much about this until cosmiconfig supports this upstream

[tianyingchun]

i just create temp module @armit/config-loader to support esm,cjs, type:module

[elijaholmos]

with cosmiconfig 8.2.0, ESM is now supported! 🎉

[tianyingchun]

it seems that their is a bug.

const loadJs: LoaderAsync = async function loadJs(filepath) {
  try {
    const { href } = pathToFileURL(filepath);
    return (await import(href)).default;
  } catch (error) {
    return loadJsSync(filepath, null);
  }
};

return (await import(href)).default; always return undefined for project

type:module

it should be changed to

const { href } = pathToFileURL(filepath);
const moduleData =  await import(href);
return moduleData.default.|| moduleData;

[tianyingchun]

consider below example
valid.config.js

import { defineConfig } from 'vite';

// it is `esm` module causeof type:`module`
export const test = defineConfig({
  cake: 'a lie',
});

it will aways return me undefined.

[Codex-]

With esm now supported I'll have to make some changes to support this, PRs welcome but I'll try look at it this week

[Codex-]

This is now in progress, draft PR here https://github.com/Codex-/cosmiconfig-typescript-loader/pull/96

[Codex-]

Progress can be tracked in #97