Test Returning None (#175)

Author: kraftp

tests/test_dbos.py

@@ -318,13 +318,16 @@ def test_retried_step(var: str) -> str:
 
 def test_recovery_workflow(dbos: DBOS) -> None:
     txn_counter: int = 0
+    txn_return_none_counter: int = 0
     wf_counter: int = 0
 
     @DBOS.workflow()
     def test_workflow(var: str, var2: str) -> str:
         nonlocal wf_counter
         wf_counter += 1
         res = test_transaction(var2)
+        should_be_none = test_transaction_return_none()
+        assert should_be_none is None
         return res + var
 
     @DBOS.transaction()
@@ -334,6 +337,13 @@ def test_transaction(var2: str) -> str:
         txn_counter += 1
         return var2 + str(rows[0][0])
 
+    @DBOS.transaction()
+    def test_transaction_return_none() -> None:
+        nonlocal txn_return_none_counter
+        DBOS.sql_session.execute(sa.text("SELECT 1")).fetchall()
+        txn_return_none_counter += 1
+        return
+
     wfuuid = str(uuid.uuid4())
     with SetWorkflowID(wfuuid):
         assert test_workflow("bob", "bob") == "bob1bob"
@@ -367,6 +377,7 @@ def test_transaction(var2: str) -> str:
     assert workflow_handles[0].get_result() == "bob1bob"
     assert wf_counter == 2
     assert txn_counter == 1
+    assert txn_return_none_counter == 1
 
     # Test that there was a recovery attempt of this
     stat = workflow_handles[0].get_status()
@@ -382,7 +393,8 @@ def test_recovery_workflow_step(dbos: DBOS) -> None:
     def test_workflow(var: str, var2: str) -> str:
         nonlocal wf_counter
         wf_counter += 1
-        test_step(var2)
+        should_be_none = test_step(var2)
+        assert should_be_none is None
         return var
 
     @DBOS.step()
@@ -432,6 +444,63 @@ def test_step(var2: str) -> None:
     assert stat.recovery_attempts == 1
 
 
+def test_workflow_returns_none(dbos: DBOS) -> None:
+    wf_counter: int = 0
+
+    @DBOS.workflow()
+    def test_workflow(var: str, var2: str) -> None:
+        nonlocal wf_counter
+        wf_counter += 1
+        assert var == var2 == "bob"
+        return
+
+    wfuuid = str(uuid.uuid4())
+    with SetWorkflowID(wfuuid):
+        assert test_workflow("bob", "bob") is None
+    assert wf_counter == 1
+
+    dbos._sys_db.wait_for_buffer_flush()
+    with SetWorkflowID(wfuuid):
+        assert test_workflow("bob", "bob") is None
+    assert wf_counter == 2
+
+    handle: WorkflowHandle[None] = DBOS.retrieve_workflow(wfuuid)
+    assert handle.get_result() == None
+    assert wf_counter == 2
+
+    # Change the workflow status to pending
+    dbos._sys_db.update_workflow_status(
+        {
+            "workflow_uuid": wfuuid,
+            "status": "PENDING",
+            "name": test_workflow.__qualname__,
+            "class_name": None,
+            "config_name": None,
+            "output": None,
+            "error": None,
+            "executor_id": None,
+            "app_id": None,
+            "app_version": None,
+            "request": None,
+            "recovery_attempts": None,
+            "authenticated_user": None,
+            "authenticated_roles": None,
+            "assumed_role": None,
+            "queue_name": None,
+        }
+    )
+
+    workflow_handles = DBOS.recover_pending_workflows()
+    assert len(workflow_handles) == 1
+    assert workflow_handles[0].get_result() is None
+    assert wf_counter == 3
+
+    # Test that there was a recovery attempt of this
+    stat = workflow_handles[0].get_status()
+    assert stat
+    assert stat.recovery_attempts == 1
+
+
 def test_recovery_temp_workflow(dbos: DBOS) -> None:
     txn_counter: int = 0