From 7ea92e6d4e5c332df9d2f8666c5f8d3c07c45f71 Mon Sep 17 00:00:00 2001
From: Hallie Lomax <hallie.lomax@gmail.com>
Date: Mon, 8 Jul 2019 11:50:03 -0700
Subject: [PATCH] helper functions to get error code and message from response
 (#658)

---
 .gitignore               |  1 +
 pynamodb/exceptions.py   |  8 ++++++++
 pynamodb/exceptions.pyi  |  4 ++++
 tests/test_exceptions.py | 42 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+)
 create mode 100644 tests/test_exceptions.py

diff --git a/.gitignore b/.gitignore
index f0a6a7381..040eb66d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -60,6 +60,7 @@ cover/
 
 # PyCharm
 .idea/
+build/
 
 # Ignore Cache
 .cache/
diff --git a/pynamodb/exceptions.py b/pynamodb/exceptions.py
index 68e1c8e9f..aa0a5ed7e 100644
--- a/pynamodb/exceptions.py
+++ b/pynamodb/exceptions.py
@@ -14,6 +14,14 @@ def __init__(self, msg=None, cause=None):
         self.cause = cause
         super(PynamoDBException, self).__init__(self.msg)
 
+    @property
+    def cause_response_code(self):
+        return getattr(self.cause, 'response', {}).get('Error', {}).get('Code')
+
+    @property
+    def cause_response_message(self):
+        return getattr(self.cause, 'response', {}).get('Error', {}).get('Message')
+
 
 class PynamoDBConnectionError(PynamoDBException):
     """
diff --git a/pynamodb/exceptions.pyi b/pynamodb/exceptions.pyi
index 728db4a7b..3b1df2e6e 100644
--- a/pynamodb/exceptions.pyi
+++ b/pynamodb/exceptions.pyi
@@ -4,6 +4,10 @@ class PynamoDBException(Exception):
     msg: str
     cause: Any
     def __init__(self, msg: Optional[Text] = ..., cause: Optional[Exception] = ...) -> None: ...
+    @property
+    def cause_response_code(self) -> Optional[str]: ...
+    @property
+    def cause_response_message(self) -> Optional[str]: ...
 
 class PynamoDBConnectionError(PynamoDBException): ...
 class DeleteError(PynamoDBConnectionError): ...
diff --git a/tests/test_exceptions.py b/tests/test_exceptions.py
new file mode 100644
index 000000000..48698f1f4
--- /dev/null
+++ b/tests/test_exceptions.py
@@ -0,0 +1,42 @@
+from botocore.exceptions import ClientError
+
+from pynamodb.exceptions import PutError
+
+
+def test_get_cause_response_code():
+    error = PutError(
+        cause=ClientError(
+            error_response={
+                'Error': {
+                    'Code': 'hello'
+                }
+            },
+            operation_name='test'
+        )
+    )
+    assert error.cause_response_code == 'hello'
+
+
+def test_get_cause_response_code__no_code():
+    error = PutError()
+    assert error.cause_response_code is None
+
+
+def test_get_cause_response_message():
+    error = PutError(
+        cause=ClientError(
+            error_response={
+                'Error': {
+                    'Message': 'hiya'
+                }
+            },
+            operation_name='test'
+        )
+    )
+    assert error.cause_response_message == 'hiya'
+
+
+def test_get_cause_response_message__no_message():
+    error = PutError()
+    assert error.cause_response_message is None
+