Fix bug and add tests for it in validate region or endpoint

src-docs/backup.py.md

@@ -54,25 +54,25 @@ Configuration for accessing S3 bucket.
 
 <a href="../src/backup.py#L38"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
-### <kbd>classmethod</kbd> `check_region_or_endpoint_set`
+### <kbd>classmethod</kbd> `check_endpoint_or_region_set`
 
 ```python
-check_region_or_endpoint_set(region: str, values: dict[str, Any]) → str
+check_endpoint_or_region_set(endpoint: str, values: dict[str, Any]) → str
 ```
 
-Validate that either that region or endpoint is set. 
+Validate that either region or endpoint is set. 
 
 
 
 **Args:**
 
- - <b>`region`</b>:  region attribute 
+ - <b>`endpoint`</b>:  endpoint attribute 
  - <b>`values`</b>:  all attributes in S3 configuration 
 
 
 
 **Returns:**
- value of the region attribute 
+ value of the endpoint attribute 
 
 
 

src/backup.py

@@ -29,31 +29,31 @@ class S3Parameters(BaseModel):
 
     access_key: str = Field(alias="access-key")
     secret_key: str = Field(alias="secret-key")
-    region: Optional[str] = Field(default=None)
+    region: Optional[str]
     bucket: str
     endpoint: Optional[str]
     path: str = Field(default="")
     s3_uri_style: str = Field(alias="s3-uri-style", default="host")
 
-    @validator("region", always=True)
+    @validator("endpoint", always=True)
     @classmethod
-    def check_region_or_endpoint_set(cls, region: str, values: dict[str, Any]) -> str:
-        """Validate that either that region or endpoint is set.
+    def check_endpoint_or_region_set(cls, endpoint: str, values: dict[str, Any]) -> str:
+        """Validate that either region or endpoint is set.
 
         Args:
-            region: region attribute
+            endpoint: endpoint attribute
             values: all attributes in S3 configuration
 
         Returns:
-            value of the region attribute
+            value of the endpoint attribute
 
         Raises:
             ValueError: if the configuration is invalid.
         """
-        endpoint = values.get("endpoint")
+        region = values.get("region")
         if not region and not endpoint:
             raise ValueError('one of "region" or "endpoint" needs to be set')
-        return region
+        return endpoint
 
 
 def can_use_bucket(s3_parameters: S3Parameters) -> bool:

tests/unit/test_backup.py

@@ -31,6 +31,51 @@ def test_s3_relation_validation_fails_when_region_and_endpoint_not_set():
         backup.S3Parameters(**s3_relation_data)
 
 
+@pytest.mark.parametrize(
+    "s3_relation_data",
+    [
+        pytest.param(
+            {
+                "access-key": token_hex(16),
+                "secret-key": token_hex(16),
+                "bucket": "synapse-backup-bucket",
+                "region": "us-west-2",
+            },
+            id="region defined but not endpoint",
+        ),
+        pytest.param(
+            {
+                "access-key": token_hex(16),
+                "secret-key": token_hex(16),
+                "bucket": "synapse-backup-bucket",
+                "endpoint": "https://example.com",
+            },
+            id="endpoint defined but not region",
+        ),
+        pytest.param(
+            {
+                "access-key": token_hex(16),
+                "secret-key": token_hex(16),
+                "bucket": "synapse-backup-bucket",
+                "region": "us-west-2",
+                "endpoint": "https://example.com",
+            },
+            id="both region and endpoint defined",
+        ),
+    ],
+)
+def test_s3_relation_validation_correct(s3_relation_data):
+    """
+    arrange: Create s3 relation data with correct data.
+    act: Create S3Parameters pydantic BaseModel from relation data.
+    assert: Relation data does not raise and region and endpoint equal
+        to the original values.
+    """
+    s3_parameters = backup.S3Parameters(**s3_relation_data)
+    assert s3_parameters.endpoint == s3_relation_data.get("endpoint")
+    assert s3_parameters.region == s3_relation_data.get("region")
+
+
 def test_can_use_bucket_wrong_boto3_resource(monkeypatch: pytest.MonkeyPatch):
     """
     arrange: Create S3Parameters and mock boto3 library so it raises on accessing S3 resource.