Require Node.js 8

.travis.yml

@@ -2,4 +2,3 @@ language: node_js
 node_js:
   - '10'
   - '8'
-  - '6'

index.js

@@ -1,10 +1,13 @@
 'use strict';
+const {promisify} = require('util');
 const through = require('through2');
 const marked = require('marked');
 const PluginError = require('plugin-error');
 
+const pMarked = promisify(marked);
+
 module.exports = options => {
-	return through.obj((file, encoding, callback) => {
+	return through.obj(async (file, encoding, callback) => {
 		if (file.isNull()) {
 			callback(null, file);
 			return;
@@ -15,17 +18,14 @@ module.exports = options => {
 			return;
 		}
 
-		marked(file.contents.toString(), options, (error, data) => {
-			if (error) {
-				callback(new PluginError('gulp-markdown', error, {fileName: file.path}));
-				return;
-			}
-
+		try {
+			const data = await pMarked(file.contents.toString(), options);
 			file.contents = Buffer.from(data);
 			file.extname = '.html';
-
 			callback(null, file);
-		});
+		} catch (error) {
+			callback(new PluginError('gulp-markdown', error, {fileName: file.path}));
+		}
 	});
 };
 

package.json

@@ -10,7 +10,7 @@
 		"url": "sindresorhus.com"
 	},
 	"engines": {
-		"node": ">=6"
+		"node": ">=8"
 	},
 	"scripts": {
 		"test": "xo && ava"