avoid coercing int subclasses to floats (#914)

pydantic · Aug 23, 2023 · 815fd92 · 815fd92
1 parent 4a1ef3a
commit 815fd92
Show file tree

Hide file tree

Showing 2 changed files with 39 additions and 2 deletions.
diff --git a/src/input/input_python.rs b/src/input/input_python.rs
@@ -303,7 +303,9 @@ impl<'a> Input<'a> for PyAny {
             if PyBool::is_exact_type_of(self) {
                 Err(ValError::new(ErrorTypeDefaults::IntType, self))
             } else {
-                Ok(EitherInt::Py(self))
+                // force to an int to upcast to a pure python int
+                let int = self.extract::<i64>()?;
+                Ok(EitherInt::I64(int))
             }
         } else {
             Err(ValError::new(ErrorTypeDefaults::IntType, self))
@@ -314,7 +316,12 @@ impl<'a> Input<'a> for PyAny {
         if PyInt::is_exact_type_of(self) {
             Ok(EitherInt::Py(self))
         } else if let Some(cow_str) = maybe_as_string(self, ErrorTypeDefaults::IntParsing)? {
+            // Try strings before subclasses of int as that will be far more common
             str_as_int(self, &cow_str)
+        } else if PyInt::is_type_of(self) {
+            // force to an int to upcast to a pure python int to maintain current behaviour
+            let int = self.extract::<i64>()?;
+            Ok(EitherInt::I64(int))
         } else if let Ok(float) = self.extract::<f64>() {
             float_as_int(self, float)
         } else {

diff --git a/tests/validators/test_int.py b/tests/validators/test_int.py
@@ -51,7 +51,7 @@ def test_int_py_and_json(py_and_json: PyAndJson, input_value, expected):
     else:
         output = v.validate_test(input_value)
         assert output == expected
-        assert isinstance(output, int)
+        assert type(output) == int
 
 
 @pytest.mark.parametrize(
@@ -405,3 +405,33 @@ def test_string_as_int_with_underscores() -> None:
             v.validate_python(edge_case)
         with pytest.raises(ValidationError):
             v.validate_json(f'"{edge_case}"')
+
+
+class IntSubclass(int):
+    pass
+
+
+def test_int_subclass() -> None:
+    v = SchemaValidator({'type': 'int'})
+    v_lax = v.validate_python(IntSubclass(1))
+    assert v_lax == 1
+    assert type(v_lax) == int
+    v_strict = v.validate_python(IntSubclass(1), strict=True)
+    assert v_strict == 1
+    assert type(v_strict) == int
+
+    assert v.validate_python(IntSubclass(1136885225876639845)) == 1136885225876639845
+    assert v.validate_python(IntSubclass(1136885225876639845), strict=True) == 1136885225876639845
+
+
+def test_int_subclass_constraint() -> None:
+    v = SchemaValidator({'type': 'int', 'gt': 0})
+    v_lax = v.validate_python(IntSubclass(1))
+    assert v_lax == 1
+    assert type(v_lax) == int
+    v_strict = v.validate_python(IntSubclass(1), strict=True)
+    assert v_strict == 1
+    assert type(v_strict) == int
+
+    with pytest.raises(ValidationError, match='Input should be greater than 0'):
+        v.validate_python(IntSubclass(0))