fix: nan inf float (#1062)

Co-authored-by: JeanArhancet <jean.arhancetebehere@gmail.com>

Author: davidhewitt

python/pydantic_core/core_schema.py

@@ -68,6 +68,8 @@ class CoreConfig(TypedDict, total=False):
         allow_inf_nan: Whether to allow infinity and NaN values for float fields. Default is `True`.
         ser_json_timedelta: The serialization option for `timedelta` values. Default is 'iso8601'.
         ser_json_bytes: The serialization option for `bytes` values. Default is 'utf8'.
+        ser_json_inf_nan: The serialization option for infinity and NaN values
+            in float fields. Default is 'null'.
         hide_input_in_errors: Whether to hide input data from `ValidationError` representation.
         validation_error_cause: Whether to add user-python excs to the __cause__ of a ValidationError.
             Requires exceptiongroup backport pre Python 3.11.
@@ -102,6 +104,7 @@ class CoreConfig(TypedDict, total=False):
     # the config options are used to customise serialization to JSON
     ser_json_timedelta: Literal['iso8601', 'float']  # default: 'iso8601'
     ser_json_bytes: Literal['utf8', 'base64', 'hex']  # default: 'utf8'
+    ser_json_inf_nan: Literal['null', 'constants']  # default: 'null'
     # used to hide input data from ValidationError repr
     hide_input_in_errors: bool
     validation_error_cause: bool  # default: False

src/errors/validation_exception.rs

@@ -324,12 +324,12 @@ impl ValidationError {
             Some(indent) => {
                 let indent = vec![b' '; indent];
                 let formatter = PrettyFormatter::with_indent(&indent);
-                let mut ser = serde_json::Serializer::with_formatter(writer, formatter);
+                let mut ser = crate::serializers::ser::PythonSerializer::with_formatter(writer, formatter);
                 serializer.serialize(&mut ser).map_err(json_py_err)?;
                 ser.into_inner()
             }
             None => {
-                let mut ser = serde_json::Serializer::new(writer);
+                let mut ser = crate::serializers::ser::PythonSerializer::new(writer);
                 serializer.serialize(&mut ser).map_err(json_py_err)?;
                 ser.into_inner()
             }

src/serializers/config.rs

@@ -189,3 +189,32 @@ pub fn utf8_py_error(py: Python, err: Utf8Error, data: &[u8]) -> PyErr {
         Err(err) => err,
     }
 }
+
+#[derive(Default, Debug, Clone, PartialEq, Eq)]
+pub(crate) enum InfNanMode {
+    #[default]
+    Null,
+    Constants,
+}
+
+impl FromStr for InfNanMode {
+    type Err = PyErr;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "null" => Ok(Self::Null),
+            "constants" => Ok(Self::Constants),
+            s => py_schema_err!(
+                "Invalid inf_nan serialization mode: `{}`, expected `null` or `constants`",
+                s
+            ),
+        }
+    }
+}
+
+impl FromPyObject<'_> for InfNanMode {
+    fn extract(ob: &'_ PyAny) -> PyResult<Self> {
+        let s = ob.extract::<&str>()?;
+        Self::from_str(s)
+    }
+}

src/serializers/errors.rs

@@ -14,8 +14,33 @@ pub(super) fn py_err_se_err<T: ser::Error, E: fmt::Display>(py_error: E) -> T {
     T::custom(py_error.to_string())
 }
 
+#[pyclass(extends=PyValueError, module="pydantic_core._pydantic_core")]
+#[derive(Debug, Clone)]
+pub struct PythonSerializerError {
+    pub message: String,
+}
+
+impl fmt::Display for PythonSerializerError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl std::error::Error for PythonSerializerError {}
+
+impl serde::ser::Error for PythonSerializerError {
+    fn custom<T>(msg: T) -> Self
+    where
+        T: fmt::Display,
+    {
+        PythonSerializerError {
+            message: format!("{msg}"),
+        }
+    }
+}
+
 /// convert a serde serialization error into a `PyErr`
-pub(super) fn se_err_py_err(error: serde_json::Error) -> PyErr {
+pub(super) fn se_err_py_err(error: PythonSerializerError) -> PyErr {
     let s = error.to_string();
     if let Some(msg) = s.strip_prefix(UNEXPECTED_TYPE_SER_MARKER) {
         if msg.is_empty() {

src/serializers/mod.rs

@@ -23,6 +23,7 @@ mod fields;
 mod filter;
 mod infer;
 mod ob_type;
+pub mod ser;
 mod shared;
 mod type_serializers;