Refactor EntryOptionPlugin to ES2015 class (#3799)

lib/EntryOptionPlugin.js

@@ -1,28 +1,28 @@
 /*
 	MIT License http://www.opensource.org/licenses/mit-license.php
 	Author Tobias Koppers @sokra
-*/
-var SingleEntryPlugin = require("./SingleEntryPlugin");
-var MultiEntryPlugin = require("./MultiEntryPlugin");
+	*/
+"use strict";
 
-function EntryOptionPlugin() {}
-module.exports = EntryOptionPlugin;
+const SingleEntryPlugin = require("./SingleEntryPlugin");
+const MultiEntryPlugin = require("./MultiEntryPlugin");
 
-EntryOptionPlugin.prototype.apply = function(compiler) {
-	compiler.plugin("entry-option", function(context, entry) {
-		function itemToPlugin(item, name) {
-			if(Array.isArray(item))
-				return new MultiEntryPlugin(context, item, name);
-			else
-				return new SingleEntryPlugin(context, item, name);
-		}
-		if(typeof entry === "string" || Array.isArray(entry)) {
-			compiler.apply(itemToPlugin(entry, "main"));
-		} else if(typeof entry === "object") {
-			Object.keys(entry).forEach(function(name) {
-				compiler.apply(itemToPlugin(entry[name], name));
-			});
-		}
-		return true;
-	});
-};
+module.exports = class EntryOptionPlugin {
+	apply(compiler) {
+		compiler.plugin("entry-option", (context, entry) => {
+			function itemToPlugin(item, name) {
+				if(Array.isArray(item)) {
+					return new MultiEntryPlugin(context, item, name);
+				} else {
+					return new SingleEntryPlugin(context, item, name);
+				}
+			}
+			if(typeof entry === "string" || Array.isArray(entry)) {
+				compiler.apply(itemToPlugin(entry, "main"));
+			} else if(typeof entry === "object") {
+				Object.keys(entry).forEach(name => compiler.apply(itemToPlugin(entry[name], name)));
+			}
+			return true;
+		});
+	}
+}