fix: map all NodeType values to span kinds in Arize Phoenix tracing (#32059)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Crazywoola <100913391+crazywoola@users.noreply.github.com>

api/tests/unit_tests/core/ops/test_arize_phoenix_trace.py

@@ -0,0 +1,36 @@
+from openinference.semconv.trace import OpenInferenceSpanKindValues
+
+from core.ops.arize_phoenix_trace.arize_phoenix_trace import _NODE_TYPE_TO_SPAN_KIND, _get_node_span_kind
+from core.workflow.enums import NodeType
+
+
+class TestGetNodeSpanKind:
+    """Tests for _get_node_span_kind helper."""
+
+    def test_all_node_types_are_mapped_correctly(self):
+        """Ensure every NodeType enum member is mapped to the correct span kind."""
+        # Mappings for node types that have a specialised span kind.
+        special_mappings = {
+            NodeType.LLM: OpenInferenceSpanKindValues.LLM,
+            NodeType.KNOWLEDGE_RETRIEVAL: OpenInferenceSpanKindValues.RETRIEVER,
+            NodeType.TOOL: OpenInferenceSpanKindValues.TOOL,
+            NodeType.AGENT: OpenInferenceSpanKindValues.AGENT,
+        }
+
+        # Test that every NodeType enum member is mapped to the correct span kind.
+        # Node types not in `special_mappings` should default to CHAIN.
+        for node_type in NodeType:
+            expected_span_kind = special_mappings.get(node_type, OpenInferenceSpanKindValues.CHAIN)
+            actual_span_kind = _get_node_span_kind(node_type)
+            assert actual_span_kind == expected_span_kind, (
+                f"NodeType.{node_type.name} was mapped to {actual_span_kind}, but {expected_span_kind} was expected."
+            )
+
+    def test_unknown_string_defaults_to_chain(self):
+        """An unrecognised node type string should still return CHAIN."""
+        assert _get_node_span_kind("some-future-node-type") == OpenInferenceSpanKindValues.CHAIN
+
+    def test_stale_dataset_retrieval_not_in_mapping(self):
+        """The old 'dataset_retrieval' string was never a valid NodeType value;
+        make sure it is not present in the mapping dictionary."""
+        assert "dataset_retrieval" not in _NODE_TYPE_TO_SPAN_KIND