Fix strict projection for string and binary (#1774)

Follow up of apache/iceberg-rust#946. Looking
at Java, this should be fine:

- String:
https://github.com/apache/iceberg/blob/19330fa19f833f481063704c1e0122e068289259/api/src/main/java/org/apache/iceberg/transforms/Truncate.java#L364-L365
- Binary:
https://github.com/apache/iceberg/blob/19330fa19f833f481063704c1e0122e068289259/api/src/main/java/org/apache/iceberg/transforms/Truncate.java#L445-L446

Author: Fokko

pyiceberg/transforms.py

@@ -817,10 +817,11 @@ def strict_project(self, name: str, pred: BoundPredicate[Any]) -> Optional[Unbou
         if isinstance(pred.term, BoundTransform):
             return _project_transform_predicate(self, name, pred)
 
+        if isinstance(pred, BoundUnaryPredicate):
+            return pred.as_unbound(Reference(name))
+
         if isinstance(field_type, (IntegerType, LongType, DecimalType)):
-            if isinstance(pred, BoundUnaryPredicate):
-                return pred.as_unbound(Reference(name))
-            elif isinstance(pred, BoundLiteralPredicate):
+            if isinstance(pred, BoundLiteralPredicate):
                 return _truncate_number_strict(name, pred, self.transform(field_type))
             elif isinstance(pred, BoundNotIn):
                 return _set_apply_transform(name, pred, self.transform(field_type))

tests/test_transforms.py

@@ -1281,6 +1281,9 @@ def test_negative_year_strict_upper_bound(bound_reference_date: BoundReference[i
 def test_strict_bucket_integer(bound_reference_int: BoundReference[int]) -> None:
     value = literal(100).to(IntegerType())
     transform = BucketTransform(num_buckets=10)
+
+    _assert_projection_strict(BoundIsNull(term=bound_reference_int), transform, AlwaysFalse)
+
     _assert_projection_strict(BoundNotEqualTo(term=bound_reference_int, literal=value), transform, NotEqualTo, "6")
 
     for expr in [BoundEqualTo, BoundLessThan, BoundLessThanOrEqual, BoundGreaterThan, BoundGreaterThanOrEqual]:
@@ -1294,6 +1297,9 @@ def test_strict_bucket_integer(bound_reference_int: BoundReference[int]) -> None
 def test_strict_bucket_long(bound_reference_long: BoundReference[int]) -> None:
     value = literal(100).to(LongType())
     transform = BucketTransform(num_buckets=10)
+
+    _assert_projection_strict(BoundIsNull(term=bound_reference_long), transform, AlwaysFalse)
+
     _assert_projection_strict(BoundNotEqualTo(term=bound_reference_long, literal=value), transform, NotEqualTo, "6")
 
     for expr in [BoundEqualTo, BoundLessThan, BoundLessThanOrEqual, BoundGreaterThan, BoundGreaterThanOrEqual]:
@@ -1308,6 +1314,9 @@ def test_strict_bucket_decimal(bound_reference_decimal: BoundReference[int]) ->
     dec = DecimalType(9, 2)
     value = literal("100.00").to(dec)
     transform = BucketTransform(num_buckets=10)
+
+    _assert_projection_strict(BoundIsNull(term=bound_reference_decimal), transform, AlwaysFalse)
+
     _assert_projection_strict(BoundNotEqualTo(term=bound_reference_decimal, literal=value), transform, NotEqualTo, "2")
 
     for expr in [BoundEqualTo, BoundLessThan, BoundLessThanOrEqual, BoundGreaterThan, BoundGreaterThanOrEqual]:
@@ -1321,6 +1330,9 @@ def test_strict_bucket_decimal(bound_reference_decimal: BoundReference[int]) ->
 def test_strict_bucket_string(bound_reference_str: BoundReference[int]) -> None:
     value = literal("abcdefg").to(StringType())
     transform = BucketTransform(num_buckets=10)
+
+    _assert_projection_strict(BoundIsNull(term=bound_reference_str), transform, AlwaysFalse)
+
     _assert_projection_strict(BoundNotEqualTo(term=bound_reference_str, literal=value), transform, NotEqualTo, "4")
 
     for expr in [BoundEqualTo, BoundLessThan, BoundLessThanOrEqual, BoundGreaterThan, BoundGreaterThanOrEqual]:
@@ -1334,6 +1346,9 @@ def test_strict_bucket_string(bound_reference_str: BoundReference[int]) -> None:
 def test_strict_bucket_bytes(bound_reference_binary: BoundReference[int]) -> None:
     value = literal(str.encode("abcdefg")).to(BinaryType())
     transform = BucketTransform(num_buckets=10)
+
+    _assert_projection_strict(BoundIsNull(term=bound_reference_binary), transform, AlwaysFalse)
+
     _assert_projection_strict(BoundNotEqualTo(term=bound_reference_binary, literal=value), transform, NotEqualTo, "4")
 
     for expr in [BoundEqualTo, BoundLessThan, BoundLessThanOrEqual, BoundGreaterThan, BoundGreaterThanOrEqual]:
@@ -1347,6 +1362,9 @@ def test_strict_bucket_bytes(bound_reference_binary: BoundReference[int]) -> Non
 def test_strict_bucket_uuid(bound_reference_uuid: BoundReference[int]) -> None:
     value = literal("00000000-0000-007b-0000-0000000001c8").to(UUIDType())
     transform = BucketTransform(num_buckets=10)
+
+    _assert_projection_strict(BoundIsNull(term=bound_reference_uuid), transform, AlwaysFalse)
+
     _assert_projection_strict(BoundNotEqualTo(term=bound_reference_uuid, literal=value), transform, NotEqualTo, "4")
 
     for expr in [BoundEqualTo, BoundLessThan, BoundLessThanOrEqual, BoundGreaterThan, BoundGreaterThanOrEqual]: