int3/foo.html

## foo.html
<html>
<body>
<script type="text/javascript" charset="utf-8" src='foo.js'></script>
</body>
</html>

## foo.js
"nothing here";
//@ sourceMappingURL=foo.js.map

## foo.js.map
{"version":3,"file":"foo.js","sources":["/a"],"names":[],"mappings":"AACA","sourcesContent":["foo"]}

## gistfile1.js
var SourceMapGenerator = require('source-map').SourceMapGenerator;

var originalFileName = '/a';
// var originalFileName = 'a'; // this works

var generator = new SourceMapGenerator({ file: 'foo.js' });
generator.addMapping({
    generated: { line: 1, column: 0 },
    original: { line: 2, column: 0 },
    source: originalFileName
});
generator.setSourceContent(originalFileName, 'foo');
console.log(generator.toString());
	<html>
	<body>
	<script type="text/javascript" charset="utf-8" src='foo.js'></script>
	</body>
	</html>
	var SourceMapGenerator = require('source-map').SourceMapGenerator;

	var originalFileName = '/a';
	// var originalFileName = 'a'; // this works

	var generator = new SourceMapGenerator({ file: 'foo.js' });
	generator.addMapping({
	generated: { line: 1, column: 0 },
	original: { line: 2, column: 0 },
	source: originalFileName
	});
	generator.setSourceContent(originalFileName, 'foo');
	console.log(generator.toString());