Test programmatic nexus handler creation

Author: dandavison

tests/nexus/test_handler_creation_at_run_time.py

@@ -0,0 +1,67 @@
+import uuid
+
+import httpx
+import nexusrpc
+import nexusrpc.handler
+
+from temporalio.client import Client
+from temporalio.worker import Worker
+from tests.helpers.nexus import create_nexus_endpoint
+
+HTTP_PORT = 7243
+
+
+def make_incrementer_service(op_names: list[str]) -> tuple[type, type]:
+    #
+    # service contract
+    #
+
+    # TODO(dan): does this work with just nexusrpc.contract.Operation[int, int]
+    op_contracts = {
+        name: nexusrpc.contract.Operation[int, int](name=name) for name in op_names
+    }
+    contract_cls = nexusrpc.contract.service(type("ServiceContract", (), op_contracts))
+
+    #
+    # service impl
+    #
+    async def _increment_op(
+        self,
+        ctx: nexusrpc.handler.StartOperationContext,
+        input: int,
+    ) -> int:
+        return input + 1
+
+    op_factories = {
+        name: nexusrpc.handler.sync_operation(_increment_op) for name in op_names
+    }
+
+    impl_cls = nexusrpc.handler.service(contract=contract_cls)(
+        type("ServiceImpl", (), op_factories)
+    )
+
+    return contract_cls, impl_cls
+
+
+async def test_handler_creation_at_run_time(client: Client):
+    task_queue = str(uuid.uuid4())
+
+    contract_cls, impl_cls = make_incrementer_service(["increment"])
+
+    service = contract_cls.__name__
+    endpoint = (await create_nexus_endpoint(task_queue, client)).endpoint.id
+    async with Worker(
+        client,
+        task_queue=task_queue,
+        nexus_services=[impl_cls()],
+    ):
+        async with httpx.AsyncClient() as http_client:
+            response = await http_client.post(
+                f"http://127.0.0.1:{HTTP_PORT}/nexus/endpoints/{endpoint}/services/{service}/increment",
+                json=1,
+                headers={},
+            )
+            print(f"\n\n{response.json()}\n\n")
+
+            assert response.status_code == 200
+            assert response.json() == 2