fix: move draft and template context handling out of create_workflow_run (#560)

* fix: move draft and template context handling out of create_workflow_run

create_workflow_run now only creates
the run with the definition_id and initial_context provided by the caller. Test call paths explicitly resolve draft definitions
and merge template context variables before creating the run, while production/runtime paths bind the published definition
without adding template defaults.

* fix: review comments

* chore: format and minor cleanups

---------

Co-authored-by: Abhishek Kumar <abhishek@a6k.me>

api/tests/test_workflow_run_creation.py

@@ -0,0 +1,146 @@
+from types import SimpleNamespace
+from unittest.mock import AsyncMock
+
+import pytest
+
+from api.services.workflow.run_creation import prepare_workflow_run_inputs
+
+
+def _workflow():
+    return SimpleNamespace(
+        id=33,
+        template_context_variables={"name": "workflow", "workflow_only": "kept"},
+        released_definition=SimpleNamespace(
+            id=77,
+            template_context_variables={
+                "name": "published",
+                "published_only": "kept",
+            },
+        ),
+        current_definition=None,
+    )
+
+
+@pytest.mark.asyncio
+async def test_prepare_inputs_uses_draft_and_merges_template_context():
+    draft = SimpleNamespace(
+        id=88,
+        template_context_variables={"name": "draft", "draft_only": "kept"},
+    )
+    workflow_client = SimpleNamespace(get_draft_version=AsyncMock(return_value=draft))
+
+    run_inputs = await prepare_workflow_run_inputs(
+        workflow_client,
+        _workflow(),
+        initial_context={"name": "explicit", "explicit_only": "kept"},
+        use_draft=True,
+        include_template_context=True,
+    )
+
+    assert run_inputs.definition_id == 88
+    assert run_inputs.initial_context == {
+        "name": "explicit",
+        "draft_only": "kept",
+        "explicit_only": "kept",
+    }
+    workflow_client.get_draft_version.assert_awaited_once_with(33)
+
+
+@pytest.mark.asyncio
+async def test_prepare_inputs_does_not_check_draft_or_merge_templates_by_default():
+    workflow_client = SimpleNamespace(get_draft_version=AsyncMock())
+
+    run_inputs = await prepare_workflow_run_inputs(
+        workflow_client,
+        _workflow(),
+        initial_context={"name": "explicit"},
+    )
+
+    assert run_inputs.definition_id == 77
+    assert run_inputs.initial_context == {"name": "explicit"}
+    workflow_client.get_draft_version.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_prepare_inputs_falls_back_to_published_when_draft_missing():
+    workflow_client = SimpleNamespace(get_draft_version=AsyncMock(return_value=None))
+
+    run_inputs = await prepare_workflow_run_inputs(
+        workflow_client,
+        _workflow(),
+        initial_context={"name": "explicit"},
+        use_draft=True,
+        include_template_context=True,
+    )
+
+    assert run_inputs.definition_id == 77
+    assert run_inputs.initial_context == {
+        "name": "explicit",
+        "published_only": "kept",
+    }
+    workflow_client.get_draft_version.assert_awaited_once_with(33)
+
+
+@pytest.mark.asyncio
+async def test_prepare_inputs_uses_current_definition_when_released_missing():
+    workflow = _workflow()
+    workflow.released_definition = None
+    workflow.current_definition = SimpleNamespace(
+        id=66,
+        template_context_variables={"name": "current", "current_only": "kept"},
+    )
+    workflow_client = SimpleNamespace(get_draft_version=AsyncMock())
+
+    run_inputs = await prepare_workflow_run_inputs(
+        workflow_client,
+        workflow,
+        include_template_context=True,
+    )
+
+    assert run_inputs.definition_id == 66
+    assert run_inputs.initial_context == {
+        "name": "current",
+        "current_only": "kept",
+    }
+    workflow_client.get_draft_version.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_prepare_inputs_falls_back_to_workflow_template_context_when_definition_context_is_none():
+    workflow = _workflow()
+    workflow.released_definition = SimpleNamespace(
+        id=77,
+        template_context_variables=None,
+    )
+    workflow_client = SimpleNamespace(get_draft_version=AsyncMock())
+
+    run_inputs = await prepare_workflow_run_inputs(
+        workflow_client,
+        workflow,
+        include_template_context=True,
+    )
+
+    assert run_inputs.definition_id == 77
+    assert run_inputs.initial_context == {
+        "name": "workflow",
+        "workflow_only": "kept",
+    }
+
+
+@pytest.mark.asyncio
+async def test_prepare_inputs_respects_empty_definition_template_context():
+    workflow = _workflow()
+    workflow.released_definition = SimpleNamespace(
+        id=77,
+        template_context_variables={},
+    )
+    workflow_client = SimpleNamespace(get_draft_version=AsyncMock())
+
+    run_inputs = await prepare_workflow_run_inputs(
+        workflow_client,
+        workflow,
+        include_template_context=True,
+    )
+
+    assert run_inputs.definition_id == 77
+    assert run_inputs.initial_context == {}