fix(dify-builder): ground model on all model-bearing nodes, carry branch handles, clean test lint

Final consolidated fix wave from whole-branch review of the Real Build +
Edit Cognition slice:

- _ground now overwrites the model dict on ANY create_node whose config
  carries a model dict (llm, question-classifier, parameter-extractor),
  not just "llm", so a drifted/hallucinated provider/name on those other
  node types no longer flows through ungrounded.
- to_intents now carries a generator edge's sourceHandle/targetHandle
  into the connect intent's args (source_handle/target_handle) so
  branching nodes (if-else, question-classifier) wire onto the correct
  port instead of collapsing onto the default handle; edges without
  handles still produce bare {from_node, to_node} args.
- Cleared the 17 ruff errors (PT018/E302/E306/E501) across the slice's
  test files by splitting composite asserts, adding missing blank
  lines, and wrapping long lines -- no assertions weakened, no noqa.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

api/tests/unit_tests/services/dify_builder/test_build_nodes.py

@@ -73,6 +73,51 @@ def test_build_nodes_degrades_to_empty_on_generator_error():
         assert build.build_nodes("t1", {}, ["x"]) == []
 
 
+def test_build_nodes_grounds_model_on_question_classifier_node():
+    gen_graph_qc = {
+        "graph": {
+            "nodes": [
+                {"id": "s", "type": "custom", "data": {"type": "start", "title": "Start", "variables": []}},
+                {
+                    "id": "qc1",
+                    "type": "custom",
+                    "data": {
+                        "type": "question-classifier",
+                        "title": "Classify",
+                        "model": {"provider": "wrong", "name": "wrong"},
+                        "classes": [],
+                    },
+                },
+                {"id": "e", "type": "custom", "data": {"type": "end", "title": "End", "outputs": []}},
+            ],
+            "edges": [
+                {"id": "e1", "source": "s", "target": "qc1"},
+                {"id": "e2", "source": "qc1", "target": "e"},
+            ],
+        },
+        "error": "",
+        "errors": [],
+    }
+    with (
+        patch.object(build, "_generator_model_config", return_value=_fake_mc("anthropic", "claude-opus-4-8")),
+        patch(
+            "services.dify_builder.agent.build.WorkflowGeneratorService.generate_workflow_graph",
+            return_value=gen_graph_qc,
+        ),
+    ):
+        intents = build.build_nodes("t1", {}, ["Classify the request"])
+
+    by_type = {}
+    for intent in intents:
+        if intent.op == "create_node":
+            by_type[intent.args["node_type"]] = intent.args["config"]
+    assert by_type["question-classifier"]["model"]["provider"] == "anthropic"  # ungrounded model overwritten
+    assert by_type["question-classifier"]["model"]["name"] == "claude-opus-4-8"
+    # no fabricated params: the fixture's node carried no completion_params, and none
+    # should be synthesized (e.g. a guessed temperature) during grounding.
+    assert "completion_params" not in by_type["question-classifier"]["model"]
+
+
 def test_build_nodes_dataset_ids_are_independent_lists_per_node():
     gen_graph_two_kb = {
         "graph": {

api/tests/unit_tests/services/dify_builder/test_graph_translate.py

@@ -15,14 +15,17 @@ def test_to_intents_translates_nodes_then_edges_and_normalizes_start():
     assert ops == [("create_node", "start"), ("create_node", "n_llm"), ("connect", ("start", "n_llm"))]
     # config carries data minus the type key; create_node args expose node_type
     start = intents[0]
-    assert start.args["node_type"] == "start" and "type" not in start.args["config"]
+    assert start.args["node_type"] == "start"
+    assert "type" not in start.args["config"]
     assert start.args["config"]["title"] == "Start"
 
+
 def test_to_intents_skips_malformed_nodes():
     from services.dify_builder.agent.graph_translate import to_intents
     graph = {"nodes": [{"id": "x", "data": {}}, {"id": "", "data": {"type": "llm"}}], "edges": []}
     assert to_intents(graph) == []  # no type / no id -> dropped
 
+
 def test_to_intents_multiple_start_nodes_only_first_normalized():
     from services.dify_builder.agent.graph_translate import to_intents
     # Graph with two start-type nodes: only first should be renamed to "start", second keeps original id
@@ -59,3 +62,36 @@ def test_to_intents_multiple_start_nodes_only_first_normalized():
     assert connects[0].args["from_node"] == "start", "Edge from s1 should be remapped to 'start'"
     # Second edge should connect from "s2" (not remapped) to "n_llm"
     assert connects[1].args["from_node"] == "s2", "Edge from s2 should keep 's2'"
+
+
+def test_to_intents_carries_branch_handles_through_connect():
+    from services.dify_builder.agent.graph_translate import to_intents
+
+    graph = {
+        "nodes": [
+            {"id": "if1", "type": "custom", "data": {"type": "if-else", "title": "If"}},
+            {"id": "n_true", "type": "custom", "data": {"type": "llm", "title": "True branch"}},
+        ],
+        "edges": [
+            {"id": "e1", "source": "if1", "target": "n_true", "sourceHandle": "true", "targetHandle": "target"},
+        ],
+    }
+    intents = to_intents(graph)
+    connect = next(i for i in intents if i.op == "connect")
+    assert connect.args["source_handle"] == "true"
+    assert connect.args["target_handle"] == "target"
+
+
+def test_to_intents_connect_without_handles_has_no_handle_keys():
+    from services.dify_builder.agent.graph_translate import to_intents
+
+    graph = {
+        "nodes": [
+            {"id": "n1", "type": "custom", "data": {"type": "start", "title": "Start"}},
+            {"id": "n2", "type": "custom", "data": {"type": "llm", "title": "LLM"}},
+        ],
+        "edges": [{"id": "e1", "source": "n1", "target": "n2"}],
+    }
+    intents = to_intents(graph)
+    connect = next(i for i in intents if i.op == "connect")
+    assert connect.args == {"from_node": "start", "to_node": "n2"}

api/tests/unit_tests/services/dify_builder/test_resources.py

@@ -6,19 +6,27 @@ def test_list_tenant_resources_normalizes_all_three_kinds():
 
     class _Model:
         def __init__(self, m): self.model = m
+
     class _ProvResp:
         def __init__(self, p, ms): self.provider, self.models = p, [_Model(m) for m in ms]
+
     class _DS:
         def __init__(self, i, n): self.id, self.name = i, n
 
+    tool_record = {
+        "provider_name": "google", "tool_name": "search",
+        "tool_label": "Google Search", "description": "",
+    }
     with patch.object(resources, "_list_models", return_value=[_ProvResp("anthropic", ["claude-opus-4-8"])]), \
          patch.object(resources, "_list_datasets", return_value=[_DS("kb-1", "Company KB")]), \
-         patch.object(resources, "_list_tools", return_value=[{"provider_name": "google", "tool_name": "search", "tool_label": "Google Search", "description": ""}]):
+         patch.object(resources, "_list_tools", return_value=[tool_record]):
         out = resources.list_tenant_resources("t1")
 
     assert out.models[0].id == "anthropic/claude-opus-4-8"
-    assert out.datasets[0].id == "kb-1" and out.datasets[0].label == "Company KB"
-    assert out.tools[0].id == "google/search" and out.tools[0].label == "Google Search"
+    assert out.datasets[0].id == "kb-1"
+    assert out.datasets[0].label == "Company KB"
+    assert out.tools[0].id == "google/search"
+    assert out.tools[0].label == "Google Search"
 
 
 def test_each_source_degrades_to_empty():
@@ -36,14 +44,20 @@ def test_mixed_failure_partial_success():
     class _DS:
         def __init__(self, i, n): self.id, self.name = i, n
 
+    tool_record = {
+        "provider_name": "google", "tool_name": "search",
+        "tool_label": "Google Search", "description": "",
+    }
     with patch.object(resources, "_list_models", side_effect=RuntimeError("boom")), \
          patch.object(resources, "_list_datasets", return_value=[_DS("kb-1", "Company KB")]), \
-         patch.object(resources, "_list_tools", return_value=[{"provider_name": "google", "tool_name": "search", "tool_label": "Google Search", "description": ""}]):
+         patch.object(resources, "_list_tools", return_value=[tool_record]):
         out = resources.list_tenant_resources("t1")
 
     assert out.models == []
-    assert len(out.datasets) == 1 and out.datasets[0].id == "kb-1"
-    assert len(out.tools) == 1 and out.tools[0].id == "google/search"
+    assert len(out.datasets) == 1
+    assert out.datasets[0].id == "kb-1"
+    assert len(out.tools) == 1
+    assert out.tools[0].id == "google/search"
 
 
 def test_malformed_tool_record_degrades():
@@ -55,4 +69,5 @@ def test_malformed_tool_record_degrades():
         out = resources.list_tenant_resources("t1")
 
     assert out.tools == []
-    assert out.models == [] and out.datasets == []
+    assert out.models == []
+    assert out.datasets == []