define UserManager.get_by_username() to get a user by username

gitlab/objects.py

@@ -573,6 +573,20 @@ def search(self, query, **kwargs):
         url = self.obj_cls._url + '?search=' + query
         return self._custom_list(url, self.obj_cls, **kwargs)
 
+    def get_by_username(self, username, **kwargs):
+        """Get a user by its username.
+
+        Returns a User object or None if the named user does not
+        exist.
+        """
+        url = self.obj_cls._url + '?username=' + username
+        results = self._custom_list(url, self.obj_cls, **kwargs)
+        assert len(results) in (0, 1)
+        try:
+            return results[0]
+        except IndexError:
+            raise GitlabGetError('no such user: ' + username)
+
 
 class CurrentUserKey(GitlabObject):
     _url = '/user/keys'

gitlab/tests/test_manager.py

@@ -258,6 +258,32 @@ def resp_get_search(url, request):
             self.assertEqual(data[0].id, 1)
             self.assertEqual(data[1].id, 2)
 
+    def test_user_manager_get_by_username(self):
+        mgr = UserManager(self.gitlab)
+
+        @urlmatch(scheme="http", netloc="localhost", path="/api/v3/users",
+                  query="username=foo", method="get")
+        def resp_get_username(url, request):
+            headers = {'content-type': 'application/json'}
+            content = '[{"name": "foo", "id": 1}]'.encode("utf-8")
+            return response(200, content, headers, None, 5, request)
+
+        with HTTMock(resp_get_username):
+            data = mgr.get_by_username('foo')
+            self.assertEqual(type(data), User)
+            self.assertEqual(data.name, "foo")
+            self.assertEqual(data.id, 1)
+
+        @urlmatch(scheme="http", netloc="localhost", path="/api/v3/users",
+                  query="username=foo", method="get")
+        def resp_get_username_nomatch(url, request):
+            headers = {'content-type': 'application/json'}
+            content = '[]'.encode("utf-8")
+            return response(200, content, headers, None, 5, request)
+
+        with HTTMock(resp_get_username_nomatch):
+            self.assertRaises(GitlabGetError, mgr.get_by_username, 'foo')
+
     def test_group_manager_search(self):
         mgr = GroupManager(self.gitlab)
 

tools/python_test.py

@@ -54,6 +54,15 @@
 assert expected == actual
 assert gl.users.search('asdf') == []
 
+assert gl.users.get_by_username('foobar') == foobar_user
+assert gl.users.get_by_username('foo') == new_user
+try:
+    gl.users.get_by_username('asdf')
+except gitlab.GitlabGetError:
+    pass
+else:
+    assert False
+
 # SSH keys
 key = new_user.keys.create({'title': 'testkey', 'key': SSH_KEY})
 assert(len(new_user.keys.list()) == 1)