Changed match strategy for variables names, to make better use of balanced npm library

Author: juliovedovatto

lib/resolve-value.js

@@ -34,12 +34,34 @@ var resolveValue = function(decl, map, /*optional*/ignorePseudoScope, /*internal
 	var resultantValue = toString(decl.value);
 	var warnings = [];
 
-
 	// Match all variables first so we can later on if there are circular dependencies
 	var variablesUsedInValue = [];
-	while ((matchingVarDecl = RE_VAR_FUNC_G.exec(resultantValue))) {
-		variablesUsedInValue.push(matchingVarDecl[1]);
+	// Create a temporary variable, storing resultantValue variable value
+	var resultantValueTemp = resultantValue;
+	// Use balanced lib to find var() declarations and store variable names
+	while ((matchingVarDecl = balanced('var(', ')', resultantValueTemp))) {
+		// Split at the comma to find variable name and fallback value
+		// There may be other commas in the values so this isn't necessarily just 2 pieces
+		var variableFallbackSplitPieces = matchingVarDecl.body.split(',');
+
+		// Get variable name and fallback, filtering empty items
+		var variableName = variableFallbackSplitPieces[0].trim();
+
+		// Push found variable to variables used array
+		variablesUsedInValue.push(variableName);
+
+		// Replace variable name (first occurence only) from result, to avoid circular loop
+		resultantValueTemp = (matchingVarDecl.pre || '') + matchingVarDecl.body.replace(variableName, '') + (matchingVarDecl.post || '');
 	}
+	// clear temporary variable
+	resultantValueTemp = undefined;
+
+	// Old strategy to find used variable names in declaration value, using RegExp
+	// TODO: remove unused block 
+	// while ((matchingVarDecl = RE_VAR_FUNC_G.exec(resultantValue))) {
+	// 	variablesUsedInValue.push(matchingVarDecl[1]);
+	// }
+
 	// Remove duplicates from array
 	variablesUsedInValue = variablesUsedInValue.filter(filterDistinct);