more react compliant whitespace - #165

lib/6to5/transformation/transformers/react.js

@@ -106,11 +106,44 @@ exports.XJSElement = {
   exit: function (node) {
     var callExpr = node.openingElement;
 
-    var childrenToRender = node.children.filter(function(child) {
-      return !(t.isLiteral(child) && _.isString(child.value) && child.value.match(/^[ \t]*[\r\n][ \t\r\n]*$/));
-    });
+    _.each(node.children, function (child) {
+      if (t.isLiteral(child)) {
+        var lines = child.value.split(/\r\n|\n|\r/);
+
+        var lastNonEmptyLine = 0;
+
+        _.each(lines, function (line, i) {
+          if (line.match(/[^ \t]/)) {
+            lastNonEmptyLine = i;
+          }
+        });
+
+        _.each(lines, function (line, i) {
+          var isFirstLine = i === 0;
+          var isLastLine = i === lines.length - 1;
+          var isLastNonEmptyLine = i === lastNonEmptyLine;
+
+          // replace rendered whitespace tabs with spaces
+          var trimmedLine = line.replace(/\t/g, ' ');
+
+          // trim whitespace touching a newline
+          if (!isFirstLine) {
+            trimmedLine = trimmedLine.replace(/^[ ]+/, '');
+          }
+
+          // trim whitespace touching an endline
+          if (!isLastLine) {
+            trimmedLine = trimmedLine.replace(/[ ]+$/, '');
+          }
+
+          if (trimmedLine || isLastNonEmptyLine) {
+            callExpr.arguments.push(t.literal(trimmedLine));
+          }
+        });
+
+        return;
+      }
 
-    _.each(childrenToRender, function (child) {
       callExpr.arguments.push(child);
     });