scripts: Unknown command or entry 'index=./src/frontend/index.js'

[cpiber]

Description

Related to webpack v5 migration: #33818.

Using the latest @wordpress/scripts (18.0.0), building with a custom entry point is not possible (npx wp-scripts build ./src/frontent/index.js).

[webpack-cli] Unknown command or entry 'index=./src/frontend/index.js'
[webpack-cli] Run 'webpack --help' to see available commands and options

Works normally without the optional path.

Works as expected in 17.1.0.

Step-by-step reproduction instructions

1. Install @wordpress/scripts@latest
2. Run npx wp-scripts build <some path>

Screenshots, screen recording, code snippet

No response

Environment info

• Ubuntu 18.04
• Node v14.17.5

Pre-checks

• I have searched the existing issues.
• I have tested with all plugins deactivated except Gutenberg.

[gziolo]

It looks like webpack 5 handles entry points differently when passed through CLI:

https://webpack.js.org/api/cli/#entry

vs

https://v4.webpack.js.org/api/cli/#usage-without-config-file

It's very likely that we can remove special handling added for webpack 4 from:

gutenberg/packages/scripts/utils/config.js

Lines 112 to 142 in 9e3be44

	/**
	* Converts a path to the entry format supported by webpack, e.g.:
	* `./entry-one.js` -> `entry-one=./entry-one.js`
	* `entry-two.js` -> `entry-two=./entry-two.js`
	*
	* @param {string} path The path provided.
	*
	* @return {string} The entry format supported by webpack.
	*/
	const pathToEntry = ( path ) => {
	const entry = basename( path, '.js' );
	if ( ! path.startsWith( './' ) ) {
	path = './' + path;
	}
	return [ entry, path ].join( '=' );
	};
	// The following handles the support for multiple entry points in webpack, e.g.:
	// `wp-scripts build one.js custom=./two.js` -> `webpack one=./one.js custom=./two.js`
	webpackArgs = webpackArgs.map( ( cliArg ) => {
	if (
	getFileArgsFromCLI().includes( cliArg ) &&
	! cliArg.includes( '=' )
	) {
	return pathToEntry( cliArg );
	}
	return cliArg;
	} );

[gziolo]

It looks like #34264 will fix this issue.

[gziolo]

There is @wordpress/scripts v18.0.1 available with the fix.