fix: search for nested field constraints on validation, ignore nulls

src/patito/validators.py

@@ -244,22 +244,34 @@ def _find_errors(  # noqa: C901
             "minLength": lambda v: col.str.len_chars() >= v,
             "maxLength": lambda v: col.str.len_chars() <= v,
         }
-        checks = [
+        if "anyOf" in column_properties:
+            checks = [
+                check(x[key])
+                for key, check in filters.items()
+                for x in column_properties["anyOf"]
+                if key in x
+            ]
+        else:
+            checks = []
+        checks += [
             check(column_properties[key])
             for key, check in filters.items()
             if key in column_properties
         ]
         if checks:
-            lazy_df = dataframe.lazy()
+            n_invalid_rows = 0
             for check in checks:
-                lazy_df = lazy_df.filter(check)
-            valid_rows = lazy_df.collect()
-            invalid_rows = dataframe.height - valid_rows.height
-            if invalid_rows > 0:
+                lazy_df = dataframe.lazy()
+                lazy_df = lazy_df.filter(
+                    ~check
+                )  # get failing rows (nulls will evaluate to null on boolean check, we only want failures (false)))
+                invalid_rows = lazy_df.collect()
+                n_invalid_rows += invalid_rows.height
+            if n_invalid_rows > 0:
                 errors.append(
                     ErrorWrapper(
                         RowValueError(
-                            f"{invalid_rows} row{'' if invalid_rows == 1 else 's'} "
+                            f"{n_invalid_rows} row{'' if n_invalid_rows == 1 else 's'} "
                             "with out of bound values."
                         ),
                         loc=column_name,

tests/test_validators.py

@@ -3,6 +3,7 @@
 import sys
 from datetime import date, datetime
 from typing import List, Optional, Union, Literal
+import re
 
 import polars as pl
 import pytest
@@ -600,3 +601,23 @@ class ListModel(pt.Model):
         # print(old, new)
         with pytest.raises(DataFrameValidationError):
             ListModel.validate(valid_df.with_columns(pl.col(old).alias(new)))
+
+
+def test_nested_field_attrs():
+    """ensure that constraints are respected even when embedded inside 'anyOf'"""
+
+    class Test(pt.Model):
+        foo: int | None = pt.Field(
+            dtype=pl.Int64, ge=0, le=100, constraints=pt.field.sum() == 100
+        )
+
+    test_df = Test.DataFrame(
+        {"foo": [110, -10]}
+    )  # meets constraint, but violates bounds (embedded in 'anyOf' in properties)
+    with pytest.raises(DataFrameValidationError) as e:
+        Test.validate(test_df)
+    pattern = re.compile(r"2 rows with out of bound values")
+    assert len(pattern.findall(str(e.value))) == 1
+
+    null_test_df = Test.DataFrame({"foo": [100, None, None]})
+    Test.validate(null_test_df)  # should not raise