npm and error messages

node_modules/webpack-sources/lib/SourceAndMapMixin.js

@@ -0,0 +1,38 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+module.exports = function mixinSourceAndMap(proto) {
+	proto.map = function(options) {
+		options = options || {};
+		if(options.columns === false) {
+			return this.listMap(options).toStringWithSourceMap({
+				file: "x"
+			}).map;
+		}
+
+		return this.node(options).toStringWithSourceMap({
+			file: "x"
+		}).map.toJSON();
+	};
+
+	proto.sourceAndMap = function(options) {
+		options = options || {};
+		if(options.columns === false) {
+			//console.log(this.listMap(options).debugInfo());
+			return this.listMap(options).toStringWithSourceMap({
+				file: "x"
+			});
+		}
+
+		var res = this.node(options).toStringWithSourceMap({
+			file: "x"
+		});
+		return {
+			source: res.code,
+			map: res.map.toJSON()
+		};
+	};
+}