Scripts: Change the plugin-zip command to add a folder in the plugin zip file by default

1. The plugin-zip command will now create a root folder in the zip file matching the name of the plugin. This aligns with the documentation stating that "By default, it uses Plugin Handbook best practices to discover files."
2. `--zip-root-folder` argument from my previous commit is now named `--root-folder`
3. The --root-folder argument will allow specifying a custom folder, or no folder for backwards compatibility.

Example usage:

{{{
npm run plugin-zip --root-folder='foo'
}}}

Follow-up to [61375], [60481].

Props justlevine, gziolo.

Author: nicolasgalvez

packages/scripts/README.md

@@ -378,12 +378,12 @@ In the case where the plugin author wants to customize the files included in the
 
 It reuses the same logic as `npm pack` command to create an npm package tarball.
 
-This is how you create a zip for use with a custom plugin update system
-
--   `--zip-root-folder` - When updating a plugin, WordPress expects a folder in the root of the zip file which matches the plugin name. The `--zip-root-folder` parameter will create a folder in the root of the zip file that matches your plugin name instead of adding all files to the root.
-
--   `npm run plugin-zip --zip-root-folder` - which will use your plugin name as the folder.
--   `npm run plugin-zip --zip-root-folder=plugin-name` - which will allow you to specify a plugin name.
+This is how you create a custom root folder inside the zip file.
+- When updating a plugin, WordPress expects a folder in the root of the zip file which matches the plugin name. So be aware that this may affect the plugin update process.
+-   `--root-folder` - Add a custom root folder to the zip file.
+-   `npm run plugin-zip` - By default, unzipping your plugin will result in a folder with the same name as your plugin.
+-   `npm run plugin-zip --root-folder=''` - This will create a zip file that has no folder inside, your plugin files will be unzipped directly into the target directory.
+-   `npm run plugin-zip --root-folder='custom-directory'` - Your plugin will be unzipped into a folder named `custom-directory`.
 
 ### `start`
 

packages/scripts/scripts/plugin-zip.js

@@ -15,8 +15,8 @@ const { hasPackageProp, getPackageProp, getArgFromCLI } = require( '../utils' );
 const name = getPackageProp( 'name' );
 stdout.write( `Creating archive for \`${ name }\` plugin... 🎁\n\n` );
 const zip = new AdmZip();
-const zipRootFolderArg = getArgFromCLI( '--zip-root-folder' );
-let zipRootFolder = null;
+const zipRootFolderArg = getArgFromCLI( '--root-folder' );
+let zipRootFolder = `${ name }/`;
 let files = [];
 
 if ( hasPackageProp( 'files' ) ) {
@@ -50,21 +50,20 @@ if ( hasPackageProp( 'files' ) ) {
 }
 
 if ( zipRootFolderArg !== undefined ) {
-	if ( zipRootFolderArg === null ) {
+	const trimmedZipRootFolderArg =
+		typeof zipRootFolderArg === 'string' ? zipRootFolderArg.trim() : null;
+	if ( ! trimmedZipRootFolderArg ) {
 		stdout.write(
-			'No value provided for `--zip-root-folder`. Using the plugin name as the root folder.\n\n'
+			'Plugin files will be zipped without a root folder.\n\n'
 		);
-		zipRootFolder = `${ name }/`;
+		zipRootFolder = '';
 	} else {
-		zipRootFolder = `${ zipRootFolderArg }/`;
+		zipRootFolder = `${ trimmedZipRootFolderArg }/`;
+		stdout.write(
+			`Adding the provided folder \`${ zipRootFolder }\` to the root of the package.\n\n`
+		);
 	}
-	stdout.write(
-		`Adding the provided folder \`${ zipRootFolder }\` to the root of the package.\n\n`
-	);
-} else {
-	zipRootFolder = '';
 }
-
 files.forEach( ( file ) => {
 	stdout.write( `  Adding \`${ file }\`.\n` );
 	const zipDirectory = dirname( file );