When updating jobs the response body may be empty

Other specific requests may need a body. Thus remove the general check
for an empty body and add a more specific one where needed.

I noticed this because when updating a Jenkins job with Jenkins Job
Builder I got an EmptyResponseException even though updating worked
correctly.

Change-Id: Ie144e6fb0b922a681e6c65ffbe5120da72a495f0

jenkins/__init__.py

@@ -368,6 +368,8 @@ class Jenkins(object):
             try:
                 response = self.jenkins_open(requests.Request(
                     'GET', self._build_url(CRUMB_URL)), add_crumb=False)
+                if not response:
+                    raise EmptyResponseException("Empty response for crumb")
             except (NotFoundException, EmptyResponseException):
                 self.crumb = False
             else:
@@ -532,16 +534,6 @@ class Jenkins(object):
         # raise exceptions if occurred
         response.raise_for_status()
 
-        headers = response.headers
-        if (headers.get('content-length') is None and
-                headers.get('transfer-encoding') is None and
-                headers.get('location') is None and
-                (response.content is None or len(response.content) <= 0)):
-            # response body should only exist if one of these is provided
-            raise EmptyResponseException(
-                "Error communicating with server[%s]: "
-                "empty response" % self.server)
-
         # Response objects will automatically return unicode encoded
         # when accessing .text property
         return response

tests/jobs/test_build.py

@@ -60,7 +60,7 @@ class JenkinsBuildJobTest(JenkinsJobsTestBase):
 
         self.assertEqual(
             str(context_mgr.exception),
-            'Error communicating with server[{0}]: empty response'.format(
+            "Header 'Location' not found in response from server[{0}]".format(
                 self.make_url('')))
 
     @patch('jenkins.requests.Session.send', autospec=True)

tests/test_jenkins.py

@@ -108,7 +108,7 @@ class JenkinsMaybeAddCrumbTest(JenkinsTestBase):
     @patch.object(jenkins.Jenkins, 'jenkins_open')
     def test_return_empty_response(self, jenkins_mock):
         "Don't try to create crumb header from an empty response"
-        jenkins_mock.side_effect = jenkins.EmptyResponseException("empty response")
+        jenkins_mock.return_value = ''
         request = jenkins.requests.Request('GET', 'http://example.com/job/TestJob')
 
         self.j.maybe_add_crumb(request)
@@ -254,11 +254,9 @@ class JenkinsOpenTest(JenkinsTestBase):
         j = jenkins.Jenkins('http://example.com', 'test', 'test')
         self.assertTrue(j.wait_for_normal_op(0))
 
-    @patch.object(jenkins.Jenkins, 'jenkins_open',
-                  side_effect=jenkins.EmptyResponseException())
     @patch.object(jenkins.Jenkins, 'get_version',
-                  side_effect=jenkins.EmptyResponseException())
+                  side_effect=jenkins.BadHTTPException())
-    def test_wait_for_normal_op__empty_response(self, version_mock, jenkins_mock):
+    def test_wait_for_normal_op__failed_response(self, version_mock):
         j = jenkins.Jenkins('http://example.com', 'test', 'test')
         self.assertFalse(j.wait_for_normal_op(0))
 

tests/test_node.py

@@ -266,11 +266,10 @@ class JenkinsCreateNodeTest(JenkinsNodesTestBase):
 
     @requests_mock.Mocker()
     def test_already_exists(self, req_mock):
-        req_mock.get(self.make_url(jenkins.CRUMB_URL))
+        req_mock.get(self.make_url(jenkins.CRUMB_URL), content=None)
         req_mock.get(
             self.make_url('computer/test_node/api/json?depth=0'),
-            status_code=200, json=self.node_info,
+            status_code=200, json=self.node_info
-            headers={'content-length': '20'}
         )
 
         with self.assertRaises(jenkins.JenkinsException) as context_manager:

tests/test_version.py

@@ -36,11 +36,10 @@ class JenkinsVersionTest(JenkinsTestBase):
             'Error communicating with server[{0}/]'.format(self.base_url))
 
     @patch('jenkins.requests.Session.send', autospec=True)
-    def test_return_empty_response(self, session_send_mock):
+    def test_return_without_version_header(self, session_send_mock):
         session_send_mock.return_value = build_response_mock(0)
-        with self.assertRaises(jenkins.EmptyResponseException) as context_manager:
+        with self.assertRaises(KeyError) as context_manager:
             self.j.get_version()
         self.assertEqual(
             str(context_manager.exception),
-            'Error communicating with server[{0}/]:'
+            "'x-jenkins'")
-            ' empty response'.format(self.base_url))