feat: add ProjectKey single-output relay node

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_project_loader.py

@@ -235,9 +235,108 @@ class TestProjectSource:
         assert ProjectSource.CATEGORY == "utils/json/project"
 
 
+class TestProjectKey:
+    def test_input_types(self):
+        from project_loader import ProjectKey
+        inputs = ProjectKey.INPUT_TYPES()
+        assert "source_label" in inputs["required"]
+        assert "key_name" in inputs["required"]
+        assert "key_type" in inputs["required"]
+
+    def test_single_output(self):
+        from project_loader import ProjectKey
+        assert len(ProjectKey.RETURN_TYPES) == 1
+        assert len(ProjectKey.RETURN_NAMES) == 1
+
+    def test_fetch_key_string(self):
+        from project_loader import ProjectKey
+        node = ProjectKey()
+        data = {"prompt": "hello", "seed": 42}
+        with patch("project_loader._fetch_data", return_value=data):
+            result = node.fetch_key(
+                source_label="my_source",
+                key_name="prompt",
+                key_type="STRING",
+                manager_url="http://localhost:8080",
+                project_name="proj1",
+                file_name="batch_i2v",
+                sequence_number=1,
+            )
+        assert result == ("hello",)
+
+    def test_fetch_key_int_coercion(self):
+        from project_loader import ProjectKey
+        node = ProjectKey()
+        data = {"seed": "42"}
+        with patch("project_loader._fetch_data", return_value=data):
+            result = node.fetch_key(
+                source_label="my_source",
+                key_name="seed",
+                key_type="INT",
+                manager_url="http://localhost:8080",
+                project_name="proj1",
+                file_name="batch_i2v",
+                sequence_number=1,
+            )
+        assert result == (42,)
+
+    def test_fetch_key_float_coercion(self):
+        from project_loader import ProjectKey
+        node = ProjectKey()
+        data = {"cfg": "1.5"}
+        with patch("project_loader._fetch_data", return_value=data):
+            result = node.fetch_key(
+                source_label="my_source",
+                key_name="cfg",
+                key_type="FLOAT",
+                manager_url="http://localhost:8080",
+                project_name="proj1",
+                file_name="batch_i2v",
+                sequence_number=1,
+            )
+        assert result == (1.5,)
+
+    def test_fetch_key_missing_key(self):
+        from project_loader import ProjectKey
+        node = ProjectKey()
+        with patch("project_loader._fetch_data", return_value={}):
+            result = node.fetch_key(
+                source_label="my_source",
+                key_name="nonexistent",
+                key_type="STRING",
+                manager_url="http://localhost:8080",
+                project_name="proj1",
+                file_name="batch_i2v",
+                sequence_number=1,
+            )
+        assert result == ("",)
+
+    def test_fetch_key_network_error(self):
+        from project_loader import ProjectKey
+        node = ProjectKey()
+        error_resp = {"error": "network_error", "message": "Connection refused"}
+        with patch("project_loader._fetch_data", return_value=error_resp):
+            with pytest.raises(RuntimeError, match="Failed to fetch"):
+                node.fetch_key(
+                    source_label="my_source",
+                    key_name="prompt",
+                    key_type="STRING",
+                    manager_url="http://localhost:8080",
+                    project_name="proj1",
+                    file_name="batch_i2v",
+                    sequence_number=1,
+                )
+
+    def test_category(self):
+        from project_loader import ProjectKey
+        assert ProjectKey.CATEGORY == "utils/json/project"
+
+
 class TestNodeMappings:
     def test_mappings_exist(self):
         from project_loader import PROJECT_NODE_CLASS_MAPPINGS, PROJECT_NODE_DISPLAY_NAME_MAPPINGS
         assert "ProjectLoaderDynamic" in PROJECT_NODE_CLASS_MAPPINGS
-        assert len(PROJECT_NODE_CLASS_MAPPINGS) == 1
-        assert len(PROJECT_NODE_DISPLAY_NAME_MAPPINGS) == 1
+        assert "ProjectSource" in PROJECT_NODE_CLASS_MAPPINGS
+        assert "ProjectKey" in PROJECT_NODE_CLASS_MAPPINGS
+        assert len(PROJECT_NODE_CLASS_MAPPINGS) == 3
+        assert len(PROJECT_NODE_DISPLAY_NAME_MAPPINGS) == 3