Cli in langium 2.0

[cdietrich]

how do i properly start the cli in langium 2.0
just using the file in bin results in

node:internal/errors:496
    ErrorCaptureStackTrace(err);
    ^

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/Users/dietrich/tmp/viechviechviech/my-hw/out/cli/main' imported from /Users/dietrich/tmp/viechviechviech/my-hw/bin/cli.js
    at new NodeError (node:internal/errors:405:5)
    at finalizeResolution (node:internal/modules/esm/resolve:226:11)
    at moduleResolve (node:internal/modules/esm/resolve:838:10)
    at defaultResolve (node:internal/modules/esm/resolve:1036:11)
    at DefaultModuleLoader.resolve (node:internal/modules/esm/loader:251:12)
    at DefaultModuleLoader.getModuleJob (node:internal/modules/esm/loader:140:32)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:76:33)
    at link (node:internal/modules/esm/module_job:75:36) {
  code: 'ERR_MODULE_NOT_FOUND'
}

Node.js v20.5.0

[msujew]

How does your bin file look like? Due to the change to ESM, it needs to be adapted as well. See our own bin file:

langium/packages/langium-cli/bin/langium.js

Lines 1 to 3 in f3cf206

	#!/usr/bin/env node
	import '../lib/langium.js';

[cdietrich]

the file the generator produces looks like

#!/usr/bin/env node

import '../out/cli/main';

just adding the file extension wont work as the default exported function from the main.js wont be executed

[cdietrich]

fixing that with an named import and calling it wont work neither as the main has this code

    program
        // eslint-disable-next-line @typescript-eslint/no-var-requires
        .version(require('../../package.json').version);

ReferenceError: require is not defined in ES module scope, you can use import instead
This file is being treated as an ES module because it has a '.js' file extension and '/Users/dietrich/tmp/viechviechviech/my-hw/package.json' contains "type": "module". To treat it as a CommonJS script, rename it to use the '.cjs' file extension.
    at default (file:///Users/dietrich/tmp/viechviechviech/my-hw/out/cli/main.js:18:10)

[msujew]

Right, the 2.0 yeoman generator for the CLI doesn't work correctly. The generated code should look more like:

import main from '../out/cli/main.js';
main();

And yes, the require in there needs to be fixed as well...

[cdietrich]

had a look at the domainmodel example.
there the logic in the main is completely different

import * as url from 'node:url';
import * as fs from 'node:fs/promises';
import * as path from 'node:path';
const __dirname = url.fileURLToPath(new URL('.', import.meta.url));

const packagePath = path.resolve(__dirname, '..', '..', 'package.json');
const packageContent = await fs.readFile(packagePath, 'utf-8');
....
program
        .version(JSON.parse(packageContent).version);

looks like these changes never made it into the generator

[cdietrich]

#1201