Revert "Revert "Add compact hosts generation.""

This reverts commit b4a86b18.

src/generate-helper.js

-module.exports = function (generateEntry, generateComment) {
+module.exports = function (generateEntry, generateComment, compact = false) {
 	return function (data) {
 		var output = '', blocks = [];
 		output += generateComment(data.header) + '\n';
@@ -10,6 +10,7 @@ module.exports = function (generateEntry, generateComment) {
 					tmp += generateComment(item.comment);
 				} else {
 					if (item.domain !== undefined) tmp += generateEntry(item.ip, item.domain) + '\n';
+					else if (compact) tmp += generateEntry(item.ip, item.domains) + '\n';
 					else {
 						item.domains.forEach(function (domain) {
 							tmp += generateEntry(item.ip, domain) + '\n';

src/generators/hosts-compact.js

+module.exports = {
+	fileName: 'hosts-compact',
+	generate: (function () {
+		var generateEntry = function (ip, domain) {
+			if (Array.isArray(domain)) domain = domain.join(' ');
+			return `${ip}\t${domain}`;
+		};
+		var generateComment = function (data) {
+			return data.replace(/^(.)/gm, '# $1');
+		};
+		return require('../generate-helper')(generateEntry, generateComment, true);
+	})()
+};