feat: add HIP-1137 response codes to ResponseCode enum and implement unit tests

Signed-off-by: Ntege Daniel <danientege785@gmail.com>

Author: danielmarv

docs/sdk_developers/hip_1137_coverage.md

@@ -11,7 +11,7 @@ This document maps HIP-1137 concepts to current SDK implementation status.
   - Block: [src/hiero_sdk_python/address_book/block_node_service_endpoint.py](../../src/hiero_sdk_python/address_book/block_node_service_endpoint.py)
   - Mirror: [src/hiero_sdk_python/address_book/mirror_node_service_endpoint.py](../../src/hiero_sdk_python/address_book/mirror_node_service_endpoint.py)
   - RPC relay: [src/hiero_sdk_python/address_book/rpc_relay_service_endpoint.py](../../src/hiero_sdk_python/address_book/rpc_relay_service_endpoint.py)
-  - General service (deferred/public API not exposed yet): [src/hiero_sdk_python/address_book/general_service_endpoint.py](../../src/hiero_sdk_python/address_book/general_service_endpoint.py)
+  - General service: [src/hiero_sdk_python/address_book/general_service_endpoint.py](../../src/hiero_sdk_python/address_book/general_service_endpoint.py)
 - Registered node transactions:
   - Create: [src/hiero_sdk_python/nodes/registered_node_create_transaction.py](../../src/hiero_sdk_python/nodes/registered_node_create_transaction.py)
   - Update: [src/hiero_sdk_python/nodes/registered_node_update_transaction.py](../../src/hiero_sdk_python/nodes/registered_node_update_transaction.py)
@@ -21,6 +21,8 @@ This document maps HIP-1137 concepts to current SDK implementation status.
 - Consensus node association fields:
   - Create: [src/hiero_sdk_python/nodes/node_create_transaction.py](../../src/hiero_sdk_python/nodes/node_create_transaction.py)
   - Update (including clear semantics): [src/hiero_sdk_python/nodes/node_update_transaction.py](../../src/hiero_sdk_python/nodes/node_update_transaction.py)
+- HIP-1137 response codes (public SDK enum):
+  - [src/hiero_sdk_python/response_code.py](../../src/hiero_sdk_python/response_code.py)
 - Registered node read models:
   - [src/hiero_sdk_python/address_book/registered_node.py](../../src/hiero_sdk_python/address_book/registered_node.py)
   - [src/hiero_sdk_python/address_book/registered_node_address_book.py](../../src/hiero_sdk_python/address_book/registered_node_address_book.py)
@@ -29,7 +31,8 @@ This document maps HIP-1137 concepts to current SDK implementation status.
 
 - `RegisteredNodeAddressBookQuery` execution is intentionally deferred until mirror-node API support is defined, matching HIP guidance:
   [src/hiero_sdk_python/address_book/registered_node_address_book_query.py](../../src/hiero_sdk_python/address_book/registered_node_address_book_query.py)
-- `GeneralServiceEndpoint` protobuf subtype is not present in the currently generated schema for this repository. The SDK includes internal forward-compatible handling, but it is not a stable public top-level API until protobuf support lands.
+- End-to-end integration coverage for the registered-node lifecycle remains gated on environment/network support in CI:
+  [tests/integration/registered_node_transaction_e2e_test.py](../../tests/integration/registered_node_transaction_e2e_test.py)
 
 ## Tests
 

src/hiero_sdk_python/__init__.py

@@ -14,6 +14,7 @@
 
 # Address book
 from .address_book.endpoint import Endpoint
+from .address_book.general_service_endpoint import GeneralServiceEndpoint
 from .address_book.mirror_node_service_endpoint import MirrorNodeServiceEndpoint
 from .address_book.node_address import NodeAddress
 from .address_book.registered_node import RegisteredNode
@@ -270,6 +271,7 @@
     "BlockNodeApi",
     "BlockNodeServiceEndpoint",
     "Endpoint",
+    "GeneralServiceEndpoint",
     "MirrorNodeServiceEndpoint",
     "NodeAddress",
     "RegisteredNode",

src/hiero_sdk_python/address_book/block_node_service_endpoint.py

@@ -26,12 +26,17 @@ def __post_init__(self) -> None:
 
     def _endpoint_type_proto(self) -> dict[str, RegisteredServiceEndpointProto.BlockNodeEndpoint]:
         """Return the protobuf block-node subtype."""
-        return {"block_node": RegisteredServiceEndpointProto.BlockNodeEndpoint(endpoint_api=int(self.endpoint_api))}
+        return {"block_node": RegisteredServiceEndpointProto.BlockNodeEndpoint(endpoint_api=[int(self.endpoint_api)])}
 
     @classmethod
     def _from_proto(cls, proto: RegisteredServiceEndpointProto) -> BlockNodeServiceEndpoint:
         """Build a block node endpoint from protobuf."""
+        endpoint_api = (
+            BlockNodeApi(proto.block_node.endpoint_api[0])
+            if len(proto.block_node.endpoint_api) > 0
+            else BlockNodeApi.OTHER
+        )
         return cls(
-            endpoint_api=BlockNodeApi(proto.block_node.endpoint_api),
+            endpoint_api=endpoint_api,
             **cls._base_kwargs_from_proto(proto),
         )

src/hiero_sdk_python/response_code.py

@@ -358,6 +358,13 @@ class ResponseCode(IntEnum):
     MISSING_BATCH_KEY = 392
     BATCH_KEY_SET_ON_NON_INNER_TRANSACTION = 393
     INVALID_BATCH_KEY = 394
+    INVALID_REGISTERED_NODE_ID = 529
+    INVALID_REGISTERED_ENDPOINT = 530
+    REGISTERED_ENDPOINTS_EXCEEDED_LIMIT = 531
+    INVALID_REGISTERED_ENDPOINT_ADDRESS = 532
+    INVALID_REGISTERED_ENDPOINT_TYPE = 533
+    REGISTERED_NODE_STILL_ASSOCIATED = 534
+    MAX_REGISTERED_NODES_EXCEEDED = 535
 
     @classmethod
     def _missing_(cls, value: object) -> ResponseCode:

tests/unit/response_code_test.py

@@ -0,0 +1,28 @@
+"""Unit tests for ResponseCode enum mappings."""
+
+from __future__ import annotations
+
+import pytest
+
+from hiero_sdk_python.response_code import ResponseCode
+
+
+pytestmark = pytest.mark.unit
+
+
+def test_hip_1137_response_codes_are_named_members():
+    """HIP-1137 response codes should be first-class enum members."""
+    assert ResponseCode(529) is ResponseCode.INVALID_REGISTERED_NODE_ID
+    assert ResponseCode(530) is ResponseCode.INVALID_REGISTERED_ENDPOINT
+    assert ResponseCode(531) is ResponseCode.REGISTERED_ENDPOINTS_EXCEEDED_LIMIT
+    assert ResponseCode(532) is ResponseCode.INVALID_REGISTERED_ENDPOINT_ADDRESS
+    assert ResponseCode(533) is ResponseCode.INVALID_REGISTERED_ENDPOINT_TYPE
+    assert ResponseCode(534) is ResponseCode.REGISTERED_NODE_STILL_ASSOCIATED
+    assert ResponseCode(535) is ResponseCode.MAX_REGISTERED_NODES_EXCEEDED
+
+
+def test_unknown_response_code_still_uses_fallback_member():
+    """Unknown integer values should continue to map to UNKNOWN_CODE_<n>."""
+    unknown_code = ResponseCode(9999)
+    assert unknown_code.is_unknown
+    assert unknown_code.name == "UNKNOWN_CODE_9999"