fix: make filters hashable again (#2556)

Author: haakonvt

cognite/client/data_classes/data_modeling/query.py

@@ -286,8 +286,13 @@ class NodeOrEdgeResultSetExpression(ResultSetExpression, ABC):
     direction: Literal["outwards", "inwards"] = "outwards"
     chain_to: Literal["destination", "source"] = "destination"
 
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, NodeOrEdgeResultSetExpression):
+            return NotImplemented
+        return type(self) is type(other) and self.dump() == other.dump()
 
-@dataclass
+
+@dataclass(eq=False)  # Prevents @dataclass from generating its own __eq__, so the parent's is used
 class NodeResultSetExpression(NodeOrEdgeResultSetExpression):
     """Describes how to query for nodes in the data model.
 
@@ -355,7 +360,7 @@ def dump(self, camel_case: bool = True) -> dict[str, Any]:
         return output
 
 
-@dataclass
+@dataclass(eq=False)  # Prevents @dataclass from generating its own __eq__, so the parent's is used
 class EdgeResultSetExpression(NodeOrEdgeResultSetExpression):
     """Describes how to query for edges in the data model.
 
@@ -439,6 +444,11 @@ class ResultSetExpressionSync(ResultSetExpressionBase, ABC):
     sync_mode: SyncMode | None = None
     backfill_sort: list[InstanceSort] = field(default_factory=list)
 
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, ResultSetExpressionSync):
+            return NotImplemented
+        return type(self) is type(other) and self.dump() == other.dump()
+
     @classmethod
     def _load(cls, resource: dict[str, Any]) -> ResultSetExpressionSync:
         if "nodes" in resource:
@@ -475,7 +485,7 @@ def _dump_sync_mode(sync_mode: SyncMode, camel_case: bool = True) -> str:
                 assert_never(sync_mode)
 
 
-@dataclass
+@dataclass(eq=False)  # Prevents @dataclass from generating its own __eq__, so the parent's is used
 class NodeResultSetExpressionSync(ResultSetExpressionSync):
     """Describes how to query for nodes in the data model.
 
@@ -562,7 +572,7 @@ def dump(self, camel_case: bool = True) -> dict[str, Any]:
         return output
 
 
-@dataclass
+@dataclass(eq=False)  # Prevents @dataclass from generating its own __eq__, so the parent's is used
 class EdgeResultSetExpressionSync(ResultSetExpressionSync):
     """Describes how to query for edges in the data model.
 

cognite/client/data_classes/filters.py

@@ -97,11 +97,6 @@ def __bool__(self) -> bool:
         )
         return True
 
-    def __eq__(self, other: object) -> bool:
-        if not isinstance(other, Filter):
-            return NotImplemented
-        return type(self) is type(other) and self.dump() == other.dump()
-
     def dump(self, camel_case_property: bool = False) -> dict[str, Any]:
         """
         Dump the filter to a dictionary.

tests/tests_unit/test_data_classes/test_data_models/test_queries.py

@@ -142,6 +142,30 @@ def test_dump(self, raw_data: dict, loaded: q.ResultSetExpression) -> None:
         assert loaded.dump(camel_case=True) == raw_data
 
 
+class TestResultSetExpressionsSync:
+    def test_dump_load_equals(self) -> None:
+        expr = q.NodeResultSetExpressionSync(
+            filter=f.Equals(property=["node", "externalId"], value="my-node"),
+            limit=10,
+            from_="bla",
+        )
+        assert expr == q.ResultSetExpressionSync.load(expr.dump(camel_case=True))
+
+    def test_load(self) -> None:
+        raw = {
+            "nodes": {
+                "filter": {"equals": {"property": ["edge", "type"], "value": {"space": "sp", "externalId": "tp"}}},
+                "chainTo": "destination",
+                "direction": "outwards",
+                "skipAlreadyDeleted": True,
+            }
+        }
+        loaded = q.NodeResultSetExpressionSync(
+            filter=f.Equals(property=["edge", "type"], value={"space": "sp", "externalId": "tp"})
+        )
+        assert q.ResultSetExpressionSync.load(raw) == loaded
+
+
 def select_load_and_dump_equals_data() -> Iterator[ParameterSet]:
     raw: dict[str, Any] = {}
     loaded = q.Select()

tests/tests_unit/test_data_classes/test_filters.py

@@ -4,7 +4,7 @@
 
 import pytest
 
-from cognite.client.data_classes.filters import And, Filter, In, Or
+from cognite.client.data_classes.filters import And, Equals, Filter, In, Or
 from tests.utils import FakeCogniteResourceGenerator
 
 
@@ -52,3 +52,15 @@ def test_filters_warn_in_boolean_contexts() -> None:
 )
 def test_filter_property_case_conversion(user_filter: Filter, expected: dict) -> None:
     assert user_filter.dump(camel_case_property=True) == expected
+
+
+def test_filter_is_hashable_and_uses_identity() -> None:
+    # Bug in 8.0.0 to 8.0.5: __eq__ was added to Filter thus implicitly setting __hash__ = None,
+    # making filters unhashable.
+    flt = Equals(property=["node", "type"], value="pump")
+    hash(flt)  # must not raise
+
+    # Hashing is identity-based: two filters with equal content hash differently.
+    flt2 = Equals(property=["node", "type"], value="pump")
+    assert hash(flt) != hash(flt2)
+    assert flt != flt2