Invalid javascript generated for empty code blocks within jsx

Notice the invalid javascript for { /* nada */ } with buble:

$ echo 'var a = (<Foo>{ /*nada*/ }<Bar>{b}</Bar></Foo>);' | bin/buble
var a = (React.createElement( Foo, null,  /*nada*/ , React.createElement( Bar, null, b ) ));

babel generates this code for the empty code block:

$ echo 'var a = (<Foo>{ /*nada*/ }<Bar>{b}</Bar></Foo>);' | babel
"use strict";

var a = React.createElement(
  Foo,
  null,
  /*nada*/React.createElement(
    Bar,
    null,
    b
  )
);

The same is true for an empty code block in buble:

$ echo 'var a = (<Foo>{}</Foo>);' | bin/buble
var a = (React.createElement( Foo, null,  ));

compared to babel:

$ echo 'var a = (<Foo>{}</Foo>);' | babel
"use strict";

var a = React.createElement(Foo, null);

or // commentsin multi line blocks (not shown).