fix(appsync): enhance consistency for custom resolver field naming in AppSync (#5801)

Fixing an error in AppSync resolver event

Co-authored-by: Ana Falcão <anafalcao@poli.ufrj.br>

Author: leandrodamascena

aws_lambda_powertools/utilities/data_classes/appsync_resolver_event.py

@@ -158,7 +158,8 @@ def __init__(self, data: dict):
 
         info: dict | None = data.get("info")
         if not info:
-            info = {"fieldName": self.get("fieldName"), "parentTypeName": self.get("typeName")}
+            parent_type_name = self.get("parentTypeName") or self.get("typeName")
+            info = {"fieldName": self.get("fieldName"), "parentTypeName": parent_type_name}
 
         self._info = AppSyncResolverEventInfo(info)
 

aws_lambda_powertools/utilities/parser/parser.py

@@ -110,7 +110,7 @@ def handler(event: Order, context: LambdaContext):
 
     logger.debug(f"Calling handler {handler.__name__}")
     return handler(parsed_event, context, **kwargs)
-  
+
 
 @overload
 def parse(event: dict[str, Any], model: type[T]) -> T: ...  # pragma: no cover
@@ -189,7 +189,7 @@ def handler(event: Order, context: LambdaContext):
         adapter = _retrieve_or_set_model_from_cache(model=model)
 
         logger.debug("Parsing and validating event model; no envelope used")
-        
+
         return _parse_and_validate_event(data=event, adapter=adapter)
 
     # Pydantic raises PydanticSchemaGenerationError when the model is not a Pydantic model
@@ -202,4 +202,4 @@ def handler(event: Order, context: LambdaContext):
             f"Error: {str(exc)}. Please ensure the Input model inherits from BaseModel,\n"
             "and your payload adheres to the specified Input model structure.\n"
             f"Model={model}",
-        ) from exc
+        ) from exc

tests/events/appSyncCustomResolverEvent.json

@@ -0,0 +1,69 @@
+{
+  "parentTypeName": "Merchant",
+  "fieldName": "locations",
+  "arguments": {
+    "page": 2
+  },
+  "identity": {
+    "claims": {
+      "sub": "07920713-4526-4642-9c88-2953512de441",
+      "iss": "https://cognito-idp.us-east-1.amazonaws.com/us-east-1_POOL_ID",
+      "aud": "58rc9bf5kkti90ctmvioppukm9",
+      "event_id": "7f4c9383-abf6-48b7-b821-91643968b755",
+      "token_use": "id",
+      "auth_time": 1615366261,
+      "name": "Michael Brewer",
+      "exp": 1615369861,
+      "iat": 1615366261
+    },
+    "defaultAuthStrategy": "ALLOW",
+    "groups": null,
+    "issuer": "https://cognito-idp.us-east-1.amazonaws.com/us-east-1_POOL_ID",
+    "sourceIp": [
+      "11.215.2.22"
+    ],
+    "sub": "07920713-4526-4642-9c88-2953512de441",
+    "username": "mike"
+  },
+  "source": {
+    "name": "Value",
+    "nested": {
+      "name": "value",
+      "list": []
+    }
+  },
+  "request": {
+    "headers": {
+      "x-forwarded-for": "11.215.2.22, 64.44.173.11",
+      "cloudfront-viewer-country": "US",
+      "cloudfront-is-tablet-viewer": "false",
+      "via": "2.0 SOMETHING.cloudfront.net (CloudFront)",
+      "cloudfront-forwarded-proto": "https",
+      "origin": "https://console.aws.amazon.com",
+      "content-length": "156",
+      "accept-language": "en-US,en;q=0.9",
+      "host": "SOMETHING.appsync-api.us-east-1.amazonaws.com",
+      "x-forwarded-proto": "https",
+      "sec-gpc": "1",
+      "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) etc.",
+      "accept": "*/*",
+      "cloudfront-is-mobile-viewer": "false",
+      "cloudfront-is-smarttv-viewer": "false",
+      "accept-encoding": "gzip, deflate, br",
+      "referer": "https://console.aws.amazon.com/",
+      "content-type": "application/json",
+      "sec-fetch-mode": "cors",
+      "x-amz-cf-id": "Fo5VIuvP6V6anIEt62WzFDCK45mzM4yEdpt5BYxOl9OFqafd-WR0cA==",
+      "x-amzn-trace-id": "Root=1-60488877-0b0c4e6727ab2a1c545babd0",
+      "authorization": "AUTH-HEADER",
+      "sec-fetch-dest": "empty",
+      "x-amz-user-agent": "AWS-Console-AppSync/",
+      "cloudfront-is-desktop-viewer": "true",
+      "sec-fetch-site": "cross-site",
+      "x-forwarded-port": "443"
+    }
+  },
+  "prev": {
+    "result": {}
+  }
+}

tests/functional/event_handler/required_dependencies/appsync/test_appsync_single_resolvers.py

@@ -26,6 +26,40 @@ def create_something(id: str):  # noqa AA03 VNE003
     assert result == "my identifier"
 
 
+def test_direct_resolver_with_parent_name():
+    # Check whether we can handle an example appsync direct resolver
+    mock_event = load_event("appSyncDirectResolver.json")
+
+    app = AppSyncResolver()
+
+    @app.resolver(field_name="createSomething", type_name="Mutation")
+    def create_something(id: str):  # noqa AA03 VNE003
+        assert app.lambda_context == {}
+        return id
+
+    # Call the implicit handler
+    result = app(mock_event, {})
+
+    assert result == "my identifier"
+
+
+def test_custom_resolver_with_fields():
+    # Check whether we can handle an example appsync with custom resolver
+    mock_event = load_event("appSyncCustomResolverEvent.json")
+
+    app = AppSyncResolver()
+
+    @app.resolver(field_name="locations", type_name="Merchant")
+    def create_something(page: int):  # noqa AA03 VNE003
+        assert app.lambda_context == {}
+        return page
+
+    # Call the implicit handler
+    result = app(mock_event, {})
+
+    assert result == 2
+
+
 def test_amplify_resolver():
     # Check whether we can handle an example appsync resolver
     mock_event = load_event("appSyncResolverEvent.json")

tests/functional/parser/test_parser.py

@@ -4,8 +4,8 @@
 
 import pydantic
 import pytest
+from pydantic import BaseModel, ValidationError
 from typing_extensions import Annotated
-from pydantic import ValidationError, BaseModel
 
 from aws_lambda_powertools.utilities.parser import event_parser, exceptions, parse
 from aws_lambda_powertools.utilities.parser.envelopes.sqs import SqsEnvelope
@@ -130,6 +130,7 @@ def handler(event, _):
     with pytest.raises(ValidationError):
         handler({"project": "powertools"}, LambdaContext())
 
+
 def test_parser_validation_error():
     class StrictModel(pydantic.BaseModel):
         age: int
@@ -143,9 +144,10 @@ def handle_validation(event: Dict, _: LambdaContext):
 
     with pytest.raises(ValidationError) as exc_info:
         handle_validation(event=invalid_event, context=LambdaContext())
-    
+
     assert "age" in str(exc_info.value)  # Verify the error mentions the invalid field
 
+
 def test_parser_type_value_errors():
     class CustomModel(pydantic.BaseModel):
         timestamp: datetime
@@ -158,7 +160,7 @@ def handle_type_validation(event: Dict, _: LambdaContext):
     # Test both TypeError and ValueError scenarios
     invalid_events = [
         {"timestamp": "invalid-date", "status": "SUCCESS"},  # Will raise ValueError for invalid date
-        {"timestamp": datetime.now(), "status": "INVALID"}   # Will raise ValueError for invalid literal
+        {"timestamp": datetime.now(), "status": "INVALID"},  # Will raise ValueError for invalid literal
     ]
 
     for invalid_event in invalid_events:
@@ -168,17 +170,19 @@ def handle_type_validation(event: Dict, _: LambdaContext):
 
 def test_event_parser_no_model():
     with pytest.raises(exceptions.InvalidModelTypeError):
+
         @event_parser
         def handler(event, _):
             return event
-        
+
         handler({}, None)
 
 
 class Shopping(BaseModel):
     id: int
     description: str
 
+
 def test_event_parser_invalid_event():
     event = {"id": "forgot-the-id", "description": "really nice blouse"}  # 'id' is invalid
 
@@ -228,6 +232,7 @@ def handler(event, _: Any) -> str:
     ret = handler(test_input, None)
     assert ret == expected
 
+
 @pytest.mark.parametrize(
     "test_input,expected",
     [