Resolve REST JSON modeled errors by shape name

codegen/gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 junit5 = "6.1.1"
-smithy = "1.71.0"
+smithy = "1.72.1"
 mockito = "5.23.0"
 test-logger-plugin = "4.0.0"
 spotbugs = "6.0.22"

packages/smithy-aws-core/.changes/next-release/smithy-aws-core-bugfix-2fbf8d3495794ec58ff3ff88e0a3caeb.json

@@ -0,0 +1,4 @@
+{
+  "type": "bugfix",
+  "description": "Fixed REST JSON modeled error resolution by matching error identifiers by shape name when wire and modeled namespaces differ. ([#742](https://github.com/smithy-lang/smithy-python/pull/742))"
+}

packages/smithy-aws-core/src/smithy_aws_core/aio/protocols.py

@@ -166,6 +166,17 @@ def content_type(self) -> str:
     def error_identifier(self) -> HTTPErrorIdentifier:
         return self._error_identifier
 
+    def _resolve_error_id(
+        self,
+        *,
+        operation: APIOperation[Any, Any],
+        error_id: ShapeID,
+    ) -> ShapeID:
+        for error_schema in operation.error_schemas:
+            if error_schema.id.name == error_id.name:
+                return error_schema.id
+        return error_id
+
     def create_event_publisher[
         OperationInput: SerializeableShape,
         OperationOutput: DeserializeableShape,

packages/smithy-http/.changes/next-release/smithy-http-enhancement-906ae181a50149ab9b8715cf77d02b86.json

@@ -0,0 +1,4 @@
+{
+  "type": "enhancement",
+  "description": "Enabled HTTP binding protocols to resolve modeled response errors when wire identifiers do not exactly match registered shape IDs. ([#742](https://github.com/smithy-lang/smithy-python/pull/742))"
+}

packages/smithy-http/src/smithy_http/aio/protocols.py

@@ -23,6 +23,7 @@
 from smithy_core.prelude import DOCUMENT
 from smithy_core.schemas import APIOperation
 from smithy_core.serializers import SerializeableShape
+from smithy_core.shapes import ShapeID
 from smithy_core.traits import EndpointTrait, HTTPTrait
 
 from ..deserializers import HTTPResponseDeserializer
@@ -185,15 +186,26 @@ async def _create_error(
         error_id = self.error_identifier.identify(
             operation=operation, response=response
         )
+        if error_id is not None and error_id not in error_registry:
+            error_id = self._resolve_error_id(
+                operation=operation,
+                error_id=error_id,
+            )
 
         if error_id is None and self._matches_content_type(response):
             if isinstance(response_body, bytearray):
                 response_body = bytes(response_body)
             deserializer = self.payload_codec.create_deserializer(source=response_body)
             document = deserializer.read_document(schema=DOCUMENT)
+            document_error_id = document.discriminator
+            if document_error_id not in error_registry:
+                document_error_id = self._resolve_error_id(
+                    operation=operation,
+                    error_id=document_error_id,
+                )
 
-            if document.discriminator in error_registry:
-                error_id = document.discriminator
+            if document_error_id in error_registry:
+                error_id = document_error_id
                 if isinstance(response_body, SeekableBytesReader):
                     response_body.seek(0)
 
@@ -236,6 +248,15 @@ async def _create_error(
             is_retry_safe=is_throttle or is_timeout or None,
         )
 
+    def _resolve_error_id(
+        self,
+        *,
+        operation: APIOperation[Any, Any],
+        error_id: ShapeID,
+    ) -> ShapeID:
+        """Resolve a response discriminator to its modeled error shape ID."""
+        return error_id
+
     def _matches_content_type(self, response: HTTPResponse) -> bool:
         if "content-type" not in response.fields:
             return False