Add method to validate ssl certificate (#421)

* Add method to validate ssl certificate

* Remove extra import from test

* Use snake case

* Address review comment

Author: Yannie Yip

tests/unit/http/test_validation_client.py

@@ -7,6 +7,7 @@
 from requests import Request
 from requests import Session
 
+from twilio.base.exceptions import TwilioRestException
 from twilio.http.validation_client import ValidationClient
 from twilio.http.response import Response
 
@@ -119,3 +120,15 @@ def test_request_with_unicode_response(self):
         self.assertEqual('test-token', self.request_mock.headers['Twilio-Client-Validation'])
         self.assertEqual(200, response.status_code)
         self.assertEqual('test, omega: Ω, pile of poop: 💩', response.content)
+
+    @patch('twilio.http.validation_client')
+    def test_validate_ssl_certificate_success(self, http_client):
+        http_client.request.return_value = Response(200, 'success')
+        self.client.validate_ssl_certificate(http_client)
+
+    @patch('twilio.http.validation_client')
+    def test_validate_ssl_certificate_error(self, http_client):
+        http_client.request.return_value = Response(504, 'error')
+
+        with self.assertRaises(TwilioRestException):
+            self.client.validate_ssl_certificate(http_client)

twilio/http/validation_client.py

@@ -2,6 +2,7 @@
 
 from requests import Request, Session
 
+from twilio.base.exceptions import TwilioRestException
 from twilio.compat import urlparse
 from twilio.http import HttpClient
 from twilio.http.response import Response
@@ -93,3 +94,13 @@ def _get_host(self, request):
         """Pull the Host out of the request"""
         parsed = urlparse(request.url)
         return parsed.netloc
+
+    def validate_ssl_certificate(self, client):
+        """
+        Validate that a request to the new SSL certificate is successful
+        :return: null on success, raise TwilioRestException if the request fails
+        """
+        response = client.request('GET', 'https://api.twilio.com:8443')
+
+        if response.status_code < 200 or response.status_code >= 300:
+            raise TwilioRestException(response.status_code, 'https://api.twilio.com:8443', 'Failed to validate SSL certificate')