Merge pull request #1146 from dbt-labs/fix-unique-path-keys-to-evalua…

…te-distinct-values

Make LinkableElementSet.only_unique_path_keys consider distinct values

metricflow/model/semantics/linkable_element_set.py

@@ -26,6 +26,35 @@ class LinkableElementSet:
     path_key_to_linkable_entities: Dict[ElementPathKey, Tuple[LinkableEntity, ...]] = field(default_factory=dict)
     path_key_to_linkable_metrics: Dict[ElementPathKey, Tuple[LinkableMetric, ...]] = field(default_factory=dict)
 
+    def __post_init__(self) -> None:
+        """Basic validation for ensuring consistency between path key type and value type."""
+        mismatched_dimensions = tuple(
+            path_key
+            for path_key in self.path_key_to_linkable_dimensions.keys()
+            if not path_key.element_type.is_dimension_type
+        )
+        mismatched_entities = tuple(
+            path_key
+            for path_key in self.path_key_to_linkable_entities
+            if path_key.element_type is not LinkableElementType.ENTITY
+        )
+        mismatched_metrics = tuple(
+            path_key
+            for path_key in self.path_key_to_linkable_metrics
+            if path_key.element_type is not LinkableElementType.METRIC
+        )
+
+        mismatched_elements = {
+            "dimensions": mismatched_dimensions,
+            "entities": mismatched_entities,
+            "metrics": mismatched_metrics,
+        }
+
+        assert all(len(mismatches) == 0 for mismatches in mismatched_elements.values()), (
+            f"Found one or more elements where the element type defined in the path key does not match the value "
+            f"type! Mismatched elements: {mismatched_elements}"
+        )
+
     @staticmethod
     def merge_by_path_key(linkable_element_sets: Sequence[LinkableElementSet]) -> LinkableElementSet:
         """Combine multiple sets together by the path key.
@@ -237,21 +266,21 @@ def as_spec_set(self) -> LinkableSpecSet:  # noqa: D102
 
     @property
     def only_unique_path_keys(self) -> LinkableElementSet:
-        """Returns a set that only includes path keys that map to a single element."""
+        """Returns a set that only includes path keys that map to a single distinct element."""
         return LinkableElementSet(
             path_key_to_linkable_dimensions={
-                path_key: linkable_dimensions
+                path_key: tuple(set(linkable_dimensions))
                 for path_key, linkable_dimensions in self.path_key_to_linkable_dimensions.items()
-                if len(linkable_dimensions) <= 1
+                if len(set(linkable_dimensions)) <= 1
             },
             path_key_to_linkable_entities={
-                path_key: linkable_entities
+                path_key: tuple(set(linkable_entities))
                 for path_key, linkable_entities in self.path_key_to_linkable_entities.items()
-                if len(linkable_entities) <= 1
+                if len(set(linkable_entities)) <= 1
             },
             path_key_to_linkable_metrics={
-                path_key: linkable_metrics
+                path_key: tuple(set(linkable_metrics))
                 for path_key, linkable_metrics in self.path_key_to_linkable_metrics.items()
-                if len(linkable_metrics) <= 1
+                if len(set(linkable_metrics)) <= 1
             },
         )

tests/model/semantics/test_linkable_element_set.py

@@ -469,7 +469,8 @@ def test_only_unique_path_keys() -> None:
     unique_path_keys = base_set.only_unique_path_keys
 
     assert unique_path_keys.path_key_to_linkable_dimensions == {
-        _time_dimension.path_key: (_time_dimension,)
+        _categorical_dimension.path_key: (_categorical_dimension,),
+        _time_dimension.path_key: (_time_dimension,),
     }, "Got an unexpected value for unique dimensions sets!"
     assert unique_path_keys.path_key_to_linkable_entities == {
         _base_entity.path_key: (_base_entity,)