Made some changes for server testing and added another get_id test.

tests/test_cognitoidentity/test_server.py

@@ -25,3 +25,21 @@ def test_create_identity_pool():
 
     json_data = json.loads(res.data.decode("utf-8"))
     assert json_data['IdentityPoolName'] == "test"
+
+
+@mock_cognitoidentity
+def test_get_id():
+    backend = server.create_backend_app("cognito-identity")
+    test_client = backend.test_client()
+
+    res = test_client.post('/',
+                           data=json.dumps({'AccountId': 'someaccount',
+                              'IdentityPoolId': 'us-west-2:12345',
+                              'Logins': {'someurl': '12345'}}),
+                           headers={
+                               "X-Amz-Target": "com.amazonaws.cognito.identity.model.AWSCognitoIdentityService.GetId"},
+                           )
+
+    print(res.data)
+    json_data = json.loads(res.data.decode("utf-8"))
+    assert ':' in json_data['IdentityId']