var app = require("express")();
​
// Handle CORS before processing requests:
app.use(function (req, res, next) {
    // This request header contains the host of the CORS client:
    var origin = req.header("Origin");
​
    // This request header contains the HTTP request method: 
    var requestMethod = req.header("Access-Control-Request-Method");
​
    if (origin === "http://www.loadmill.com"
        || origin === "https://www.loadmill.com") {
​
        // This response header allows CORS from loadmill.com:
        res.header("Access-Control-Allow-Origin", origin);
​
        // This response header is required only if you use cookies in your tests:
        res.header("Access-Control-Allow-Credentials", 'true');
​
        if (req.method === 'OPTIONS' && origin && requestMethod) {
            // It's a pre-flight request:
​
            // This request header contains the request headers of the pre-flighted request:
            var requestHeaders = req.header("Access-Control-Request-Headers");
​
            setPreFlightHeaders(res, requestMethod || "", requestHeaders || "");
            return res.sendStatus(204);
        }
        else {
            // If your test scenario involves reading response headers, 
            // we automatically include them in this request header:
            var exposedHeaders = req.header("Loadmill-Request-Expose-Headers") || "";
​
            // This response header allows the test client to read the desired headers from the response:
            res.header("Access-Control-Expose-Headers", exposedHeaders);
        }
    }
    return next();
});
​
function setPreFlightHeaders(res, allowedMethod, allowedHeaders) {
    res.header({
        // This response header asks the browser not to pre-flight 
        // the same request URL again for the next 24 hours:
        "Access-Control-Max-Age": "86400",
​
        // These response headers approve the request method and headers specified:
        "Access-Control-Allow-Methods": allowedMethod,
        "Access-Control-Allow-Headers": allowedHeaders
    });
}