Reorganize fixtures and implement a happy path test for semantic_mani…

…fest (#9930)

.changes/unreleased/Under the Hood-20240416-150030.yaml

@@ -0,0 +1,6 @@
+kind: Under the Hood
+body: Add a test for semantic manifest and move test fixtures needed for it
+time: 2024-04-16T15:00:30.614286-07:00
+custom:
+  Author: ChenyuLInx
+  Issue: "9665"

core/dbt/artifacts/resources/v1/semantic_model.py

@@ -42,7 +42,7 @@ class NodeRelation(dbtClassMixin):
     alias: str
     schema_name: str  # TODO: Could this be called simply "schema" so we could reuse StateRelation?
     database: Optional[str] = None
-    relation_name: Optional[str] = None
+    relation_name: Optional[str] = ""
 
 
 # ====================================

tests/unit/conftest.py

@@ -4,6 +4,9 @@
 from dbt.artifacts.resources.types import NodeType
 from dbt.contracts.graph.nodes import SourceDefinition
 
+# All manifest related fixtures.
+from tests.unit.utils.manifest import *  # noqa
+
 
 @pytest.fixture
 def basic_parsed_source_definition_object():

tests/unit/contracts/graph/test_semantic_manifest.py

@@ -0,0 +1,28 @@
+import pytest
+from dbt.contracts.graph.semantic_manifest import SemanticManifest
+
+
+# Overwrite the default nods to construct the manifest
+@pytest.fixture
+def nodes(metricflow_time_spine_model):
+    return [metricflow_time_spine_model]
+
+
+@pytest.fixture
+def semantic_models(
+    semantic_model,
+) -> list:
+    return [semantic_model]
+
+
+@pytest.fixture
+def metrics(
+    metric,
+) -> list:
+    return [metric]
+
+
+class TestSemanticManifest:
+    def test_validate(self, manifest):
+        sm_manifest = SemanticManifest(manifest)
+        assert sm_manifest.validate()