Fix validation of negative floats when using multiple_of (#1077)

Co-authored-by: David Hewitt <[email protected]>

Author: Viicos

src/validators/float.rs

@@ -109,7 +109,7 @@ impl Validator for ConstrainedFloatValidator {
         }
         if let Some(multiple_of) = self.multiple_of {
             let rem = float % multiple_of;
-            let threshold = float / 1e9;
+            let threshold = float.abs() / 1e9;
             if rem.abs() > threshold && (rem - multiple_of).abs() > threshold {
                 return Err(ValError::new(
                     ErrorType::MultipleOf {

tests/validators/test_decimal.py

@@ -188,6 +188,7 @@ def test_decimal_kwargs(py_and_json: PyAndJson, kwargs: Dict[str, Any], input_va
         (0.1, 1, None),
         (0.1, 1.0, None),
         (0.1, int(5e10), None),
+        (2.0, -2.0, None),
     ],
     ids=repr,
 )

tests/validators/test_float.py

@@ -121,6 +121,7 @@ def test_float_kwargs(py_and_json: PyAndJson, kwargs: Dict[str, Any], input_valu
         (0.1, 1, None),
         (0.1, 1.0, None),
         (0.1, int(5e10), None),
+        (2.0, -2.0, None),
     ],
     ids=repr,
 )