x-ray: Add #ua()

Closes #4.

Author: Stephen Mathieson

lib/request.js

@@ -25,7 +25,10 @@ function driver(opts) {
   return function plugin(xray) {
 
     xray.request = function request(url, fn) {
-      superagent.get(url, function(err, res) {
+      var req = superagent.get(url);
+      var ua = xray.ua();
+      if (ua) req.set('User-Agent', ua);
+      req.end(function(err, res) {
         if (err) return fn(err);
         else return fn(null, res.text);
       });

lib/x-ray.js

@@ -37,7 +37,7 @@ module.exports = Xray;
 function Xray(url) {
   if (!(this instanceof Xray)) return new Xray(url);
 
-
+  this._ua = null;
   this._format = function(o) { return o };
   this._paginate = false;
   this._limit = Infinity;
@@ -140,7 +140,19 @@ Xray.prototype.prepare = function(str, fn) {
   return this;
 };
 
+/**
+ * Get/set the request user agent.
+ *
+ * @param {String} [ua]
+ * @return {Xray|String}
+ * @api public
+ */
 
+Xray.prototype.ua = function(ua){
+  if (!arguments.length) return this._ua;
+  this._ua = ua;
+  return this;
+};
 
 /**
  * Paginate

test/x-ray.js

@@ -44,6 +44,19 @@ describe('x-ray', function() {
     })
   });
 
+  describe('#ua(str)', function(){
+    it('should set the user agent', function(done){
+      xray('http://whatsmyuseragent.com/')
+      .ua('foo/bar')
+      .select('h2.info')
+      .run(function(err, ua){
+        if (err) return done(err);
+        assert('foo/bar' == ua);
+        done();
+      })
+    })
+  })
+
   it('should support arrays', function(done) {
     xray('http://mat.io')
       .select(['.Header-list-item a'])