adds tilejson provider tests

test/provider.tilejson.js

@@ -0,0 +1,36 @@
+var torque = require('../lib/torque/core');
+
+var windshaft, url;
+var lastCall;
+var old_net;
+QUnit.module('provider.tilejson', {
+  setup: function() {
+    old_net = torque.net.jsonp;
+    old_get = torque.net.get;
+    torque.net.jsonp = function(url, callback) {
+      lastCall = url;
+      callback({ layergroupid: 'testlg', metadata: { torque: { 0: { data_steps:10 }} } });
+    };
+    torque.net.get = function(url, callback) {
+      lastCall = url;
+      var tilejson = '{"tiles": ["./{z}/{x}/{y}.json.torque"], "end": 903000, "column_type": "number", "start": 1000, "data_steps": 1, "resolution": 32}';
+      callback({response: tilejson});
+    };
+    windshaft = new torque.providers.tileJSON({
+      tileJSON: 'http://what.ev.er/tilejson.json',
+      cartocss: '#test{}',
+      resolution: 1,
+      steps: 10
+    });
+  }, 
+  teardown: function() {
+    torque.net.jsonp = old_net;
+    torque.net.get = old_get;
+  }
+});
+
+test("tile urls should be correctly formed for relative urls", function() {
+  windshaft._ready = true;
+  windshaft.getTileData({x: 0, y: 1, corrected: {x: 0, y: 1}}, 2, function() {});
+  equal(lastCall,"http://what.ev.er/./2/0/1.json.torque");
+});