I want to pipe a readable css file to the http response - node.js

Question

I have an issue with outputting the readable stream to the http response.
behind the scenes there is a regular request and response streams coming from the generic http createServer. I check to see if the 'req.url' ends in css, and I create a readable stream of this file. I see the css contents in the console.log, with the right css code I expect. Then, I try to pipe the readable css file stream to the response, but in Chrome, the file response is blank when I inspect the response. It is a 200 response though. Any thoughts at first glance? I've tried different variations of where I have code commented out.
router.addRoute("[a-aA-z0-9]{1,50}.css$", function(matches){
var cssFile = matches[0];
var pathToCss = process.cwd() + "/" + cssFile;
// takes care of os diffs regarding path delimiters and such
pathToCss = path.normalize(pathToCss);
console.log(matches);
console.log("PATH TO CSS");
console.log(pathToCss)
var readable = fs.createReadStream(pathToCss);
var write = function(chunk){
this.queue(chunk.toString());
console.log(chunk.toString());
}
var end = function(){
this.queue(null);
}
var thru = through(write,end);
//req.on("end",function(){
res.pipe(readable.pipe(thru)).pipe(res);
//res.end();
//});
});

Answer 1

you need to pipe your readable stream into your through-stream, and then pipe it into the response:
readable.pipe(thru).pipe(res);
edit: for preparing your css path, just use path.join instead of concatenating your path and normalizing it:
var pathToCss = path.join(process.cwd(), cssFile);

Answer 2

I separated out this route (css) from my normal html producing routes, the problem I had was that my normal routes in my router object returned strings, like res.end(compiled_html_str), and the css file readable stream was going through that same routing function. I made it separate by isolating it from my router.
var cssMatch = [];
if(cssMatch = req.url.match(/.+\/(.+\.css$)/)){
res.writeHead({"Content-Type":"text/css"});
var cssFile = cssMatch[1];
var pathToCss = process.cwd() + "/" + cssFile;
// takes care of os diffs regarding path delimiters and such
pathToCss = path.normalize(pathToCss);
console.log(cssMatch);
console.log("PATH TO CSS");
console.log(pathToCss)
var readable = fs.createReadStream(pathToCss);
var cssStr = "";
readable.on("data",function(chunk){
cssStr += chunk.toString();
});
readable.on("end",function(){
res.end(cssStr);
});
}