Enhance readme CLI command to support standalone plugins

bin/plugin/commands/readme.js

@@ -15,6 +15,7 @@ const { getChangelog } = require( './changelog' );
  * @typedef WPReadmeCommandOptions
  *
  * @property {string=} milestone Optional milestone title, to update the changelog in the readme.
+ * @property {string=} path      Optional path to the readme.txt file to update. If omitted, it will be detected via --milestone.
  * @property {string=} token     Optional personal GitHub access token, only relevant for changelog updates.
  */
 
@@ -24,6 +25,7 @@ const { getChangelog } = require( './changelog' );
  * @property {string}  owner     GitHub repository owner.
  * @property {string}  repo      GitHub repository name.
  * @property {string=} milestone Optional milestone title, to update the changelog in the readme.
+ * @property {string=} path      Optional path to the readme.txt file to update.
  * @property {string=} token     Optional personal GitHub access token, only relevant for changelog updates.
  */
 
@@ -32,6 +34,11 @@ exports.options = [
 		argname: '-m, --milestone <milestone>',
 		description: 'Milestone title, to update the changelog',
 	},
+	{
+		argname: '-p, --path <path>',
+		description:
+			'Path to the readme.txt file to update; if omitted, it will be detected via --milestone',
+	},
 	{
 		argname: '-t, --token <token>',
 		description: 'GitHub token',
@@ -48,20 +55,53 @@ exports.handler = async ( opt ) => {
 		owner: config.githubRepositoryOwner,
 		repo: config.githubRepositoryName,
 		milestone: opt.milestone,
+		path: opt.path,
 		token: opt.token,
 	} );
 };
 
+/**
+ * Detects the path to the readme.txt file to update based on the milestone title.
+ *
+ * @param {string} milestone Milestone title.
+ *
+ * @return {string} Detected readme.txt path.
+ */
+function detectReadmePath( milestone ) {
+	const slug = milestone.match( /^([a-z0-9-]+) / );
+	if ( ! slug ) {
+		throw new Error(
+			`The ${ milestone } milestone does not start with a valid plugin slug.`
+		);
+	}
+
+	if ( 'performance-lab' === slug[ 1 ] ) {
+		return 'readme.txt';
+	}
+
+	return `plugins/${ slug[ 1 ] }/readme.txt`;
+}
+
 /**
  * Updates the `readme.txt` file with the given changelog.
  *
  * @param {string}           changelog Changelog in markdown, with trailing newline.
  * @param {WPReadmeSettings} settings  Readme settings.
  */
 function updateReadmeChangelog( changelog, settings ) {
-	const regex = new RegExp( `= ${ settings.milestone } =[^=]+` );
+	// Detect the version number to replace it in readme changelog, if already present.
+	const version = settings.milestone.match(
+		/\d+\.\d+(\.\d+)?(-[A-Za-z0-9.]+)?$/
+	);
+	if ( ! version ) {
+		throw new Error(
+			`The ${ settings.milestone } milestone does not end with a version number.`
+		);
+	}
 
-	const readmeFile = path.join( '.', 'readme.txt' );
+	const regex = new RegExp( `= ${ version[ 0 ] } =[^=]+` );
+
+	const readmeFile = path.join( '.', settings.path );
 	const fileContent = fs.readFileSync( readmeFile, 'utf8' );
 
 	let newContent;
@@ -95,6 +135,10 @@ async function updateReadme( settings ) {
 		);
 
 		try {
+			if ( ! settings.path ) {
+				settings.path = detectReadmePath( settings.milestone );
+			}
+
 			const changelog = await getChangelog( {
 				owner: settings.owner,
 				repo: settings.repo,
@@ -108,6 +152,8 @@ async function updateReadme( settings ) {
 				return;
 			}
 		}
-		log( formats.success( `\n💃readme.txt successfully updated\n\n` ) );
+		log(
+			formats.success( `\n💃${ settings.path } successfully updated\n\n` )
+		);
 	}
 }