ignore trailing commas when inferring newlines - fixes #1304

src/babel/generation/whitespace.js

@@ -38,12 +38,11 @@ export default class Whitespace {
     var startToken;
     var endToken;
     var tokens = this.tokens;
-    var token;
 
     for (var j = 0; j < tokens.length; j++) {
       // optimize for forward traversal by shifting for loop index
       var i = getLookupIndex(j, this._lastFoundIndex, this.tokens.length);
-      token = tokens[i];
+      var token = tokens[i];
 
       // this is the token this node starts with
       if (node.start === token.start) {
@@ -62,17 +61,17 @@ export default class Whitespace {
     var startToken;
     var endToken;
     var tokens = this.tokens;
-    var token;
 
     for (var j = 0; j < tokens.length; j++) {
       // optimize for forward traversal by shifting for loop index
       var i = getLookupIndex(j, this._lastFoundIndex, this.tokens.length);
-      token = tokens[i];
+      var token = tokens[i];
 
       // this is the token this node ends with
       if (node.end === token.end) {
         startToken = token;
         endToken = tokens[i + 1];
+        if (endToken.type.label === ",") endToken = tokens[i + 2];
 
         this._lastFoundIndex = i;
         break;

src/babel/helpers/parse.js

@@ -14,7 +14,6 @@ export default function (code, opts = {}) {
     strictMode:                  opts.strictMode,
     sourceType:                  opts.sourceType,
     locations:                   true,
-    onComment:                   comments,
     features:                    opts.features || {},
     plugins:                     opts.plugins || {},
     onToken:                     tokens,