feat(resources): Balance (#35)

lib/resources/Balance.js

@@ -0,0 +1,11 @@
+'use strict';
+
+var TelnyxResource = require('../TelnyxResource');
+
+module.exports = TelnyxResource.extend({
+  path: 'balance',
+
+  retrieve: TelnyxResource.method({
+    method: 'GET',
+  })
+});

lib/telnyx.js

@@ -65,7 +65,8 @@ var resources = {
   OtaUpdates: require('./resources/OtaUpdates'),
   MobileOperatorNetworks: require('./resources/MobileOperatorNetworks'),
   SimCardGroups: require('./resources/SimCardGroups'),
-  NumberLookup: require('./resources/NumberLookup')
+  NumberLookup: require('./resources/NumberLookup'),
+  Balance: require('./resources/Balance'),
 };
 
 Telnyx.TelnyxResource = require('./TelnyxResource');

test/resources/Balance.spec.js

@@ -0,0 +1,19 @@
+'use strict';
+
+var telnyx = require('../../testUtils').getTelnyxMock();
+var expect = require('chai').expect;
+
+describe('Balance Resource', function() {
+  describe('retrieve', function() {
+    it('Sends the correct request', function() {
+      return telnyx.balance.retrieve()
+        .then(function(response) {
+          expect(response.data).to.include({record_type: 'balance'});
+          expect(response.data).to.have.property('balance');
+          expect(response.data).to.have.property('available_credit');
+          expect(response.data).to.have.property('currency');
+          expect(response.data).to.have.property('credit_limit');
+        });
+    });
+  });
+});