Test cases - WIP

src/registrar/utility/s3_bucket.py

@@ -1,14 +1,45 @@
 """Utilities for accessing an AWS S3 bucket"""
 
+from enum import IntEnum
 import boto3
-
+from botocore.exceptions import ClientError
 from django.conf import settings
 from django.template.loader import get_template
 
+class S3ClientErrorCodes(IntEnum):
+    """Used for S3ClientError
+    Error code overview:
+        - 1 ACCESS_S3_CLIENT_ERROR
+        - 2 UPLOAD_FILE_ERROR
+        - 3 FILE_NOT_FOUND_ERROR
+        - 4 GET_FILE_ERROR
+    """
+
+    ACCESS_S3_CLIENT_ERROR = 1
+    UPLOAD_FILE_ERROR = 2
+    FILE_NOT_FOUND_ERROR = 3
+    GET_FILE_ERROR = 4
 
 class S3ClientError(RuntimeError):
     """Local error for handling all failures with boto3.client"""
-    pass
+    _error_mapping = {
+        S3ClientErrorCodes.ACCESS_S3_CLIENT_ERROR: "Failed to establish a connection with the storage service.",
+        S3ClientErrorCodes.UPLOAD_FILE_ERROR: "File upload to the storage service failed.",
+        S3ClientErrorCodes.FILE_NOT_FOUND_ERROR: "Requested file not found in the storage service.",
+        S3ClientErrorCodes.GET_FILE_ERROR: (
+            "Retrieval of the requested file from " 
+            "the storage service failed due to an unspecified error."
+        ),
+    }
+
+    def __init__(self, *args, code=None, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.code = code
+        if self.code in self._error_mapping:
+            self.message = self._error_mapping.get(self.code)
+
+    def __str__(self):
+        return f"{self.message}"
 
 
 class S3ClientHelper:
@@ -23,7 +54,7 @@ class S3ClientHelper:
                 config=settings.BOTO_CONFIG,
             )
         except Exception as exc:
-            raise S3ClientError("Could not access the S3 client") from exc
+            raise S3ClientError(code=S3ClientErrorCodes.ACCESS_S3_CLIENT_ERROR) from exc
 
     def get_bucket_name(self):
         """Gets the name of our S3 Bucket"""
@@ -34,17 +65,20 @@ class S3ClientHelper:
         try:
             response = self.boto_client.upload_file(file_path, self.get_bucket_name(), file_name)
         except Exception as exc:
-            raise S3ClientError("Couldn't upload file") from exc
+            raise S3ClientError(code=S3ClientErrorCodes.UPLOAD_FILE_ERROR) from exc
         return response
 
     def get_file(self, file_name, decode_to_utf=False):
         """Gets a file to our S3 instance and returns the file content"""
         try:
             response = self.boto_client.get_object(Bucket=self.get_bucket_name(), Key=file_name)
-        except self.boto_client.exceptions.NoSuchKey as exc:
-            raise S3ClientError("File was not found") from exc
+        except ClientError as exc:
+            if exc.response['Error']['Code'] == 'NoSuchKey':
+                raise S3ClientError(code=S3ClientErrorCodes.FILE_NOT_FOUND_ERROR) from exc
+            else:
+                raise S3ClientError(code=S3ClientErrorCodes.GET_FILE_ERROR) from exc
         except Exception as exc:
-            raise S3ClientError("Couldn't get file, an unspecified error occured") from exc
+            raise S3ClientError(code=S3ClientErrorCodes.GET_FILE_ERROR) from exc
 
         file_content = response["Body"].read()
         if decode_to_utf: