fix(exceptions): properly initialize BotoCoreError subclasses with message formatting

src/s3_encryption/exceptions.py

@@ -5,6 +5,24 @@
 This module contains custom exception classes used throughout the S3 Encryption Client.
 """
 
+from botocore.exceptions import BotoCoreError
 
-class S3EncryptionClientError(Exception):
-    """Exception class for S3 Encryption Client errors."""
+
+class S3EncryptionClientError(BotoCoreError):
+    """Exception class for non-Security S3 Encryption Client errors."""
+
+    fmt = "{msg}"
+
+    def __init__(self, message="An unspecified S3 Encryption Client error occurred"):
+        """Initialize the exception with a message."""
+        super().__init__(msg=message)
+
+
+class S3EncryptionClientSecurityError(BotoCoreError):
+    """Security Exceptions for S3 Encryption Client errors."""
+
+    fmt = "{msg}"
+
+    def __init__(self, message="An unspecified S3 Encryption Client Security error occurred"):
+        """Initialize the exception with a message."""
+        super().__init__(msg=message)

test/test_exceptions.py

@@ -0,0 +1,51 @@
+import pytest
+from botocore.exceptions import BotoCoreError
+
+from s3_encryption.exceptions import (
+    S3EncryptionClientError,
+    S3EncryptionClientSecurityError,
+)
+
+
+class TestS3EncryptionClientError:
+    def test_default_message(self):
+        error = S3EncryptionClientError()
+        assert str(error) == "An unspecified S3 Encryption Client error occurred"
+
+    def test_custom_message(self):
+        error = S3EncryptionClientError("Custom error message")
+        assert str(error) == "Custom error message"
+
+    def test_empty_message(self):
+        error = S3EncryptionClientError("")
+        assert str(error) == ""
+
+    def test_inherits_from_botocore_error(self):
+        error = S3EncryptionClientError("test")
+        assert isinstance(error, BotoCoreError)
+
+    def test_can_be_caught_as_botocore_error(self):
+        with pytest.raises(BotoCoreError):
+            raise S3EncryptionClientError("test error")
+
+
+class TestS3EncryptionClientSecurityError:
+    def test_default_message(self):
+        error = S3EncryptionClientSecurityError()
+        assert str(error) == "An unspecified S3 Encryption Client Security error occurred"
+
+    def test_custom_message(self):
+        error = S3EncryptionClientSecurityError("Custom security error")
+        assert str(error) == "Custom security error"
+
+    def test_empty_message(self):
+        error = S3EncryptionClientSecurityError("")
+        assert str(error) == ""
+
+    def test_inherits_from_botocore_error(self):
+        error = S3EncryptionClientSecurityError("test")
+        assert isinstance(error, BotoCoreError)
+
+    def test_can_be_caught_as_botocore_error(self):
+        with pytest.raises(BotoCoreError):
+            raise S3EncryptionClientSecurityError("test security error")