chart.js

exports.drawChart = function(data) {
  var document = jsdom.jsdom();

	var margin = {
		top : 40,
		right : 40,
		bottom : 40,
		left : 40
	};
	var width = 500 - margin.left - margin.right;
	var height = 250 - margin.top - margin.bottom;

	var x = d3.scale.ordinal().rangeRoundBands([ 0, width ], .1, .3);

	var y = d3.scale.linear().range([ height, 0 ]);

	var xAxis = d3.svg.axis().scale(x).orient("bottom");

	var yAxis = d3.svg.axis().scale(y).orient("left").ticks(8, '%');

	var svg = d3.select(document.body)
  .append("svg")
  .attr("version", 1.1)
  .attr("xmlns", "http://www.w3.org/2000/svg")
  .attr("width",width + margin.left + margin.right)
  .attr("height",height + margin.top + margin.bottom)
  .append("g")
  .attr("transform","translate(" + margin.left + "," + margin.top + ")");
  var style='\n /* <![CDATA[ */\n.bar {\n  fill: steelblue;\n}\n\n.bar:hover {\n  fill: brown;\n}\n\n.title {\n  font: bold 14px "Helvetica Neue", Helvetica, Arial, sans-serif;\n}\n\n.axis {\n  font: 10px sans-serif;\n}\n\n.axis path,\n.axis line {\n  fill: none;\n  stroke: #000;\n  shape-rendering: crispEdges;\n}\n\n.x.axis path {\n  display: none;\n}\n /* ]]> */\n';
  svg.append("style")
  .attr('type','text/css')
  .text(style);

	x.domain(data.map(function(d) {
		return d.name;
	}));
	y.domain([ 0, d3.max(data, function(d) {
		return d.value;
	}) ]);

	svg.append("g").attr("class", "x axis").attr("transform",
			"translate(0," + height + ")").call(xAxis).selectAll(".tick text")
			.call(wrap, x.rangeBand());

	svg.append("g").attr("class", "y axis").call(yAxis);

	svg.selectAll(".bar").data(data).enter().append("rect")
			.attr("class", "bar").attr("x", function(d) {
				return x(d.name);
			}).attr("width", x.rangeBand()).attr("y", function(d) {
				return y(d.value);
			}).attr("height", function(d) {
				return height - y(d.value);
			});

	function wrap(text, width) {
		text.each(function() {
					var text = d3.select(this);
          var words = text.text().split(/\s+/).reverse();
          var word;
          var line = [];
          var lineNumber = 0;
          var lineHeight = 1.1; // ems
					var y = text.attr("y");
          var dy = parseFloat(text.attr("dy"));
          var tspan = text.text(null).append("tspan").attr("x", 0).attr("y",y).attr("dy", dy + "em");
          while (word = words.pop()) {
						line.push(word);
						tspan.text(line.join(" "));
            //FIXME if (tspan.node().getComputedTextLength() > width) {
            if (0 > width) {
							line.pop();
							tspan.text(line.join(" "));
							line = [ word ];
							tspan = text.append("tspan").attr("x", 0).attr("y",
									y).attr("dy",
									++lineNumber * lineHeight + dy + "em")
									.text(word);
						}
					}
				});
	}

	function type(d) {
		d.value = +d.value;
		return d;
	}

  return d3.select(document.body).html();
}

The problem in my code was basic, just missing add the style attribute (type='text/css') in the tag style:
svg.append("style").attr('type','text/css')
In browsers work fine without this attribute, but in a SVG file is very important