Add option to preserve empty URL paths (#1789)

Co-authored-by: Victorien <[email protected]>

Author: davidhewitt

python/pydantic_core/core_schema.py

@@ -3908,6 +3908,7 @@ def url_schema(
     default_host: str | None = None,
     default_port: int | None = None,
     default_path: str | None = None,
+    preserve_empty_path: bool | None = None,
     strict: bool | None = None,
     ref: str | None = None,
     metadata: dict[str, Any] | None = None,
@@ -3932,6 +3933,7 @@ def url_schema(
         default_host: The default host to use if the URL does not have a host
         default_port: The default port to use if the URL does not have a port
         default_path: The default path to use if the URL does not have a path
+        preserve_empty_path: Whether to preserve an empty path or convert it to '/', default False
         strict: Whether to use strict URL parsing
         ref: optional unique identifier of the schema, used to reference the schema in other places
         metadata: Any other information you want to include with the schema, not used by pydantic-core
@@ -3945,6 +3947,7 @@ def url_schema(
         default_host=default_host,
         default_port=default_port,
         default_path=default_path,
+        preserve_empty_path=preserve_empty_path,
         strict=strict,
         ref=ref,
         metadata=metadata,
@@ -3974,6 +3977,7 @@ def multi_host_url_schema(
     default_host: str | None = None,
     default_port: int | None = None,
     default_path: str | None = None,
+    preserve_empty_path: bool | None = None,
     strict: bool | None = None,
     ref: str | None = None,
     metadata: dict[str, Any] | None = None,
@@ -3998,6 +4002,7 @@ def multi_host_url_schema(
         default_host: The default host to use if the URL does not have a host
         default_port: The default port to use if the URL does not have a port
         default_path: The default path to use if the URL does not have a path
+        preserve_empty_path: Whether to preserve an empty path or convert it to '/', default False
         strict: Whether to use strict URL parsing
         ref: optional unique identifier of the schema, used to reference the schema in other places
         metadata: Any other information you want to include with the schema, not used by pydantic-core
@@ -4011,6 +4016,7 @@ def multi_host_url_schema(
         default_host=default_host,
         default_port=default_port,
         default_path=default_path,
+        preserve_empty_path=preserve_empty_path,
         strict=strict,
         ref=ref,
         metadata=metadata,

src/serializers/infer.rs

@@ -197,11 +197,11 @@ pub(crate) fn infer_to_python_known(
             }
             ObType::Url => {
                 let py_url: PyUrl = value.extract()?;
-                py_url.__str__().into_py_any(py)?
+                py_url.__str__(py).into_py_any(py)?
             }
             ObType::MultiHostUrl => {
                 let py_url: PyMultiHostUrl = value.extract()?;
-                py_url.__str__().into_py_any(py)?
+                py_url.__str__(py).into_py_any(py)?
             }
             ObType::Uuid => {
                 let uuid = super::type_serializers::uuid::uuid_to_string(value)?;
@@ -476,11 +476,11 @@ pub(crate) fn infer_serialize_known<S: Serializer>(
         }
         ObType::Url => {
             let py_url: PyUrl = value.extract().map_err(py_err_se_err)?;
-            serializer.serialize_str(py_url.__str__())
+            serializer.serialize_str(py_url.__str__(value.py()))
         }
         ObType::MultiHostUrl => {
             let py_url: PyMultiHostUrl = value.extract().map_err(py_err_se_err)?;
-            serializer.serialize_str(&py_url.__str__())
+            serializer.serialize_str(&py_url.__str__(value.py()))
         }
         ObType::PydanticSerializable => {
             let py = value.py();
@@ -644,11 +644,11 @@ pub(crate) fn infer_json_key_known<'a>(
         }
         ObType::Url => {
             let py_url: PyUrl = key.extract()?;
-            Ok(Cow::Owned(py_url.__str__().to_string()))
+            Ok(Cow::Owned(py_url.__str__(key.py()).to_string()))
         }
         ObType::MultiHostUrl => {
             let py_url: PyMultiHostUrl = key.extract()?;
-            Ok(Cow::Owned(py_url.__str__()))
+            Ok(Cow::Owned(py_url.__str__(key.py()).to_string()))
         }
         ObType::Tuple => {
             let mut key_build = super::type_serializers::tuple::KeyBuilder::new();

src/serializers/type_serializers/url.rs

@@ -46,7 +46,7 @@ macro_rules! build_serializer {
                 let py = value.py();
                 match value.extract::<$extract>() {
                     Ok(py_url) => match extra.mode {
-                        SerMode::Json => py_url.__str__().into_py_any(py),
+                        SerMode::Json => py_url.__str__(value.py()).into_py_any(py),
                         _ => Ok(value.clone().unbind()),
                     },
                     Err(_) => {
@@ -58,7 +58,7 @@ macro_rules! build_serializer {
 
             fn json_key<'a>(&self, key: &'a Bound<'_, PyAny>, extra: &Extra) -> PyResult<Cow<'a, str>> {
                 match key.extract::<$extract>() {
-                    Ok(py_url) => Ok(Cow::Owned(py_url.__str__().to_string())),
+                    Ok(py_url) => Ok(Cow::Owned(py_url.__str__(key.py()).to_string())),
                     Err(_) => {
                         extra.warnings.on_fallback_py(self.get_name(), key, extra)?;
                         infer_json_key(key, extra)
@@ -75,7 +75,7 @@ macro_rules! build_serializer {
                 extra: &Extra,
             ) -> Result<S::Ok, S::Error> {
                 match value.extract::<$extract>() {
-                    Ok(py_url) => serializer.serialize_str(&py_url.__str__()),
+                    Ok(py_url) => serializer.serialize_str(&py_url.__str__(value.py())),
                     Err(_) => {
                         extra
                             .warnings