Add value_type parameter back to entities

Signed-off-by: Felix Wang <wangfelix98@gmail.com>

sdk/python/feast/entity.py

@@ -58,6 +58,7 @@ def __init__(
         *,
         name: str,
         join_keys: Optional[List[str]] = None,
+        value_type: Optional[ValueType] = None,
         description: str = "",
         tags: Optional[Dict[str, str]] = None,
         owner: str = "",
@@ -70,6 +71,8 @@ def __init__(
             join_keys (optional): A list of properties that uniquely identifies different entities
                 within the collection. This currently only supports a list of size one, but is
                 intended to eventually support multiple join keys.
+            value_type (optional): The type of the entity, such as string or float. If not specified,
+                it will be inferred from the schema of the underlying data source.
             description (optional): A human-readable description.
             tags (optional): A dictionary of key-value pairs to store arbitrary metadata.
             owner (optional): The owner of the entity, typically the email of the primary maintainer.
@@ -78,7 +81,7 @@ def __init__(
             ValueError: Parameters are specified incorrectly.
         """
         self.name = name
-        self.value_type = ValueType.UNKNOWN
+        self.value_type = value_type or ValueType.UNKNOWN
 
         if join_keys and len(join_keys) > 1:
             # TODO(felixwang9817): When multiple join keys are supported, add a `join_keys` attribute

sdk/python/feast/feature_view.py

@@ -35,7 +35,9 @@
 from feast.protos.feast.core.FeatureView_pb2 import (
     MaterializationInterval as MaterializationIntervalProto,
 )
+from feast.types import from_value_type
 from feast.usage import log_exceptions
+from feast.value_type import ValueType
 
 warnings.simplefilter("once", DeprecationWarning)
 
@@ -115,6 +117,7 @@ def __init__(
                 If a stream source, the source should contain a batch_source for backfills & batch materialization.
             schema (optional): The schema of the feature view, including feature, timestamp,
                 and entity columns.
+            # TODO: clarify that schema is only useful here...
             entities (optional): The list of entities with which this group of features is associated.
             ttl (optional): The amount of time this group of features lives. A ttl of 0 indicates that
                 this group of features lives forever. Note that large ttl's or a ttl of 0
@@ -160,9 +163,29 @@ def __init__(
             for entity in entities:
                 join_keys.append(entity.join_key)
 
+        # Ensure that entities have unique join keys.
+        if len(set(join_keys)) < len(join_keys):
+            raise ValueError(
+                "A feature view should not have entities that share a join key."
+            )
+
         for field in self.schema:
             if field.name in join_keys:
                 self.entity_columns.append(field)
+
+                # Confirm that the inferred type matches the specified entity type, if it exists.
+                matching_entities = (
+                    [e for e in entities if e.join_key == field.name]
+                    if entities
+                    else []
+                )
+                assert len(matching_entities) == 1
+                entity = matching_entities[0]
+                if entity.value_type != ValueType.UNKNOWN:
+                    if from_value_type(entity.value_type) != field.dtype:
+                        raise ValueError(
+                            f"Entity {entity.name} has type {entity.value_type}, which does not match the inferred type {field.dtype}."
+                        )
             else:
                 features.append(field)
 

sdk/python/feast/inference.py

@@ -135,8 +135,7 @@ def update_feature_views_with_inferred_features_and_entities(
                 if field.name not in [feature.name for feature in fv.features]:
                     fv.features.append(field)
 
-        # Since the `value_type` parameter has not yet been fully deprecated for
-        # entities, we respect the `value_type` attribute if it still exists.
+        # Respect the `value_type` attribute of the entity, if it is specified.
         for entity_name in fv.entities:
             entity = entity_name_to_entity_map[entity_name]
             if (

sdk/python/tests/unit/infra/test_inference_unit_tests.py

@@ -15,6 +15,7 @@
 from feast.on_demand_feature_view import on_demand_feature_view
 from feast.repo_config import RepoConfig
 from feast.types import Float32, Float64, Int64, String, UnixTimestamp
+from feast.value_type import ValueType
 from tests.utils.data_source_test_creator import prep_file_source
 
 
@@ -216,6 +217,78 @@ def test_feature_view_inference_respects_basic_inference():
     assert len(feature_view_2.entity_columns) == 2
 
 
+def test_feature_view_inference_on_entity_value_types():
+    """
+    Tests that feature view inference correctly uses the entity `value_type` attribute.
+    """
+    entity1 = Entity(
+        name="test1", join_keys=["id_join_key"], value_type=ValueType.INT64
+    )
+    file_source = FileSource(path="some path")
+    feature_view_1 = FeatureView(
+        name="test1",
+        entities=[entity1],
+        schema=[Field(name="int64_col", dtype=Int64)],
+        source=file_source,
+    )
+
+    assert len(feature_view_1.schema) == 1
+    assert len(feature_view_1.features) == 1
+    assert len(feature_view_1.entity_columns) == 0
+
+    update_feature_views_with_inferred_features_and_entities(
+        [feature_view_1],
+        [entity1],
+        RepoConfig(
+            provider="local", project="test", entity_key_serialization_version=2
+        ),
+    )
+
+    # The schema is only used as a parameter, as is therefore not updated during inference.
+    assert len(feature_view_1.schema) == 1
+
+    # Since there is already a feature specified, additional features are not inferred.
+    assert len(feature_view_1.features) == 1
+
+    # The single entity column is inferred correctly and has the expected type.
+    assert len(feature_view_1.entity_columns) == 1
+    assert feature_view_1.entity_columns[0].dtype == Int64
+
+
+def test_conflicting_entity_value_types():
+    """
+    Tests that an error is thrown when the entity value types conflict.
+    """
+    entity1 = Entity(
+        name="test1", join_keys=["id_join_key"], value_type=ValueType.INT64
+    )
+    file_source = FileSource(path="some path")
+
+    with pytest.raises(ValueError):
+        _ = FeatureView(
+            name="test1",
+            entities=[entity1],
+            schema=[
+                Field(name="int64_col", dtype=Int64),
+                Field(
+                    name="id_join_key", dtype=Float64
+                ),  # Conflicts with the defined entity
+            ],
+            source=file_source,
+        )
+
+    # There should be no error here.
+    _ = FeatureView(
+        name="test1",
+        entities=[entity1],
+        schema=[
+            Field(name="int64_col", dtype=Int64),
+            Field(name="id_join_key", dtype=Int64),  # Conflicts with the defined entity
+        ],
+        source=file_source,
+    )
+
+
 def test_feature_view_inference_on_entity_columns(simple_dataset_1):
     """
     Tests that feature view inference correctly infers entity columns.

sdk/python/tests/unit/test_feature_views.py

@@ -15,6 +15,20 @@
 from feast.types import Float32
 
 
+def test_create_feature_view_with_conflicting_entities():
+    user1 = Entity(name="user1", join_keys=["user_id"])
+    user2 = Entity(name="user2", join_keys=["user_id"])
+    batch_source = FileSource(path="some path")
+
+    with pytest.raises(ValueError):
+        _ = FeatureView(
+            name="test",
+            entities=[user1, user2],
+            ttl=timedelta(days=30),
+            source=batch_source,
+        )
+
+
 def test_create_batch_feature_view():
     batch_source = FileSource(path="some path")
     BatchFeatureView(