add banner option. Fixes #1735

lib/less/parser.js

@@ -351,20 +351,22 @@ less.Parser = function Parser(env) {
         // @param [additionalData] An optional map which can contains vars - a map (key, value) of variables to apply
         //
         parse: function (str, callback, additionalData) {
-            var root, line, lines, error = null, globalVars, modifyVars;
+            var root, line, lines, error = null, globalVars, modifyVars, preText = "";
 
             i = j = currentPos = furthest = 0;
 
             globalVars = (additionalData && additionalData.globalVars) ? less.Parser.serializeVars(additionalData.globalVars) + '\n' : '';
             modifyVars = (additionalData && additionalData.modifyVars) ? '\n' + less.Parser.serializeVars(additionalData.modifyVars) : '';
+
+            if (globalVars || (additionalData && additionalData.banner)) {
+                preText = ((additionalData && additionalData.banner) ? additionalData.banner : "") + globalVars;
+                parser.imports.contentsIgnoredChars[env.currentFileInfo.filename] = preText.length;
+            }
+
             str = str.replace(/\r\n/g, '\n');
             // Remove potential UTF Byte Order Mark
-            input = str = globalVars + str.replace(/^\uFEFF/, '') + modifyVars;
-
+            input = str = preText + str.replace(/^\uFEFF/, '') + modifyVars;
             parser.imports.contents[env.currentFileInfo.filename] = str;
-            if (globalVars) {
-                parser.imports.contentsIgnoredChars[env.currentFileInfo.filename] = globalVars.length;
-            }
 
             // Split the input into chunks.
             chunks = (function (input) {

test/css/globalVars/extended.css

@@ -1,3 +1,6 @@
+/**
+  * Test
+  */
 #header {
   color: #333333;
   border-left: 1px;

test/css/globalVars/simple.css

@@ -1,3 +1,6 @@
+/**
+  * Test
+  */
 .class {
   color: #ff0000;
 }

test/index.js

@@ -38,7 +38,7 @@ lessTester.runTestSet({strictMath: true, strictUnits: true, sourceMap: true, glo
         }
         return path.join('test/sourcemaps', filename) + '.json'; 
     });
-lessTester.runTestSet({globalVars: true}, "globalVars/",
+lessTester.runTestSet({globalVars: true, banner: "/**\n  * Test\n  */\n"}, "globalVars/",
     null, null, null, function(name) { return path.join('test/less/', name) + '.json'; });
 lessTester.runTestSet({modifyVars: true}, "modifyVars/",
     null, null, null, function(name) { return path.join('test/less/', name) + '.json'; });

test/less-test.js

@@ -217,6 +217,9 @@ module.exports = function() {
             } else if (options.modifyVars) {
                 additionalData.modifyVars = options.getVars(path);
             }
+            if (options.banner) {
+                additionalData.banner = options.banner;
+            }
             parser.parse(str, function (err, tree) {
                 if (err) {
                     callback(err);