use serde::de::{self, Deserializer, Error as DeError, Visitor};
use serde::forward_to_deserialize_any;
use crate::path::{Path, PathIter};
use crate::ResourcePath;
macro_rules! unsupported_type {
($trait_fn:ident, $name:expr) => {
fn $trait_fn<V>(self, _: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom(concat!(
"unsupported type: ",
$name
)))
}
};
}
macro_rules! parse_single_value {
($trait_fn:ident, $visit_fn:ident, $tp:tt) => {
fn $trait_fn<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
if self.path.len() != 1 {
Err(de::value::Error::custom(
format!(
"wrong number of parameters: {} expected 1",
self.path.len()
)
.as_str(),
))
} else {
let v = self.path[0].parse().map_err(|_| {
de::value::Error::custom(format!(
"can not parse {:?} to a {}",
&self.path[0], $tp
))
})?;
visitor.$visit_fn(v)
}
}
};
}
pub struct PathDeserializer<'de, T: ResourcePath> {
path: &'de Path<T>,
}
impl<'de, T: ResourcePath + 'de> PathDeserializer<'de, T> {
pub fn new(path: &'de Path<T>) -> Self {
PathDeserializer { path }
}
}
impl<'de, T: ResourcePath + 'de> Deserializer<'de> for PathDeserializer<'de, T> {
type Error = de::value::Error;
fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_map(ParamsDeserializer {
params: self.path.iter(),
current: None,
})
}
fn deserialize_struct<V>(
self,
_: &'static str,
_: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
self.deserialize_map(visitor)
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_unit_struct<V>(
self,
_: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
self.deserialize_unit(visitor)
}
fn deserialize_newtype_struct<V>(
self,
_: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
fn deserialize_tuple<V>(
self,
len: usize,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
if self.path.len() < len {
Err(de::value::Error::custom(
format!(
"wrong number of parameters: {} expected {}",
self.path.len(),
len
)
.as_str(),
))
} else {
visitor.visit_seq(ParamsSeq {
params: self.path.iter(),
})
}
}
fn deserialize_tuple_struct<V>(
self,
_: &'static str,
len: usize,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
if self.path.len() < len {
Err(de::value::Error::custom(
format!(
"wrong number of parameters: {} expected {}",
self.path.len(),
len
)
.as_str(),
))
} else {
visitor.visit_seq(ParamsSeq {
params: self.path.iter(),
})
}
}
fn deserialize_enum<V>(
self,
_: &'static str,
_: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
if self.path.is_empty() {
Err(de::value::Error::custom(
"expeceted at least one parameters",
))
} else {
visitor.visit_enum(ValueEnum {
value: &self.path[0],
})
}
}
fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
if self.path.is_empty() {
Err(de::value::Error::custom(
format!("wrong number of parameters: {} expected 1", self.path.len())
.as_str(),
))
} else {
visitor.visit_borrowed_str(&self.path[0])
}
}
fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_seq(ParamsSeq {
params: self.path.iter(),
})
}
unsupported_type!(deserialize_any, "'any'");
unsupported_type!(deserialize_bytes, "bytes");
unsupported_type!(deserialize_option, "Option<T>");
unsupported_type!(deserialize_identifier, "identifier");
unsupported_type!(deserialize_ignored_any, "ignored_any");
parse_single_value!(deserialize_bool, visit_bool, "bool");
parse_single_value!(deserialize_i8, visit_i8, "i8");
parse_single_value!(deserialize_i16, visit_i16, "i16");
parse_single_value!(deserialize_i32, visit_i32, "i32");
parse_single_value!(deserialize_i64, visit_i64, "i64");
parse_single_value!(deserialize_u8, visit_u8, "u8");
parse_single_value!(deserialize_u16, visit_u16, "u16");
parse_single_value!(deserialize_u32, visit_u32, "u32");
parse_single_value!(deserialize_u64, visit_u64, "u64");
parse_single_value!(deserialize_f32, visit_f32, "f32");
parse_single_value!(deserialize_f64, visit_f64, "f64");
parse_single_value!(deserialize_string, visit_string, "String");
parse_single_value!(deserialize_byte_buf, visit_string, "String");
parse_single_value!(deserialize_char, visit_char, "char");
}
struct ParamsDeserializer<'de, T: ResourcePath> {
params: PathIter<'de, T>,
current: Option<(&'de str, &'de str)>,
}
impl<'de, T: ResourcePath> de::MapAccess<'de> for ParamsDeserializer<'de, T> {
type Error = de::value::Error;
fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error>
where
K: de::DeserializeSeed<'de>,
{
self.current = self.params.next().map(|ref item| (item.0, item.1));
match self.current {
Some((key, _)) => Ok(Some(seed.deserialize(Key { key })?)),
None => Ok(None),
}
}
fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>
where
V: de::DeserializeSeed<'de>,
{
if let Some((_, value)) = self.current.take() {
seed.deserialize(Value { value })
} else {
Err(de::value::Error::custom("unexpected item"))
}
}
}
struct Key<'de> {
key: &'de str,
}
impl<'de> Deserializer<'de> for Key<'de> {
type Error = de::value::Error;
fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_str(self.key)
}
fn deserialize_any<V>(self, _visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom("Unexpected"))
}
forward_to_deserialize_any! {
bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
byte_buf option unit unit_struct newtype_struct seq tuple
tuple_struct map struct enum ignored_any
}
}
macro_rules! parse_value {
($trait_fn:ident, $visit_fn:ident, $tp:tt) => {
fn $trait_fn<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
let v = self.value.parse().map_err(|_| {
de::value::Error::custom(format!(
"can not parse {:?} to a {}",
self.value, $tp
))
})?;
visitor.$visit_fn(v)
}
};
}
struct Value<'de> {
value: &'de str,
}
impl<'de> Deserializer<'de> for Value<'de> {
type Error = de::value::Error;
parse_value!(deserialize_bool, visit_bool, "bool");
parse_value!(deserialize_i8, visit_i8, "i8");
parse_value!(deserialize_i16, visit_i16, "i16");
parse_value!(deserialize_i32, visit_i32, "i16");
parse_value!(deserialize_i64, visit_i64, "i64");
parse_value!(deserialize_u8, visit_u8, "u8");
parse_value!(deserialize_u16, visit_u16, "u16");
parse_value!(deserialize_u32, visit_u32, "u32");
parse_value!(deserialize_u64, visit_u64, "u64");
parse_value!(deserialize_f32, visit_f32, "f32");
parse_value!(deserialize_f64, visit_f64, "f64");
parse_value!(deserialize_string, visit_string, "String");
parse_value!(deserialize_byte_buf, visit_string, "String");
parse_value!(deserialize_char, visit_char, "char");
fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_unit_struct<V>(
self,
_: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_borrowed_bytes(self.value.as_bytes())
}
fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_borrowed_str(self.value)
}
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_some(self)
}
fn deserialize_enum<V>(
self,
_: &'static str,
_: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_enum(ValueEnum { value: self.value })
}
fn deserialize_newtype_struct<V>(
self,
_: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
fn deserialize_tuple<V>(self, _: usize, _: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom("unsupported type: tuple"))
}
fn deserialize_struct<V>(
self,
_: &'static str,
_: &'static [&'static str],
_: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom("unsupported type: struct"))
}
fn deserialize_tuple_struct<V>(
self,
_: &'static str,
_: usize,
_: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom("unsupported type: tuple struct"))
}
unsupported_type!(deserialize_any, "any");
unsupported_type!(deserialize_seq, "seq");
unsupported_type!(deserialize_map, "map");
unsupported_type!(deserialize_identifier, "identifier");
}
struct ParamsSeq<'de, T: ResourcePath> {
params: PathIter<'de, T>,
}
impl<'de, T: ResourcePath> de::SeqAccess<'de> for ParamsSeq<'de, T> {
type Error = de::value::Error;
fn next_element_seed<U>(&mut self, seed: U) -> Result<Option<U::Value>, Self::Error>
where
U: de::DeserializeSeed<'de>,
{
match self.params.next() {
Some(item) => Ok(Some(seed.deserialize(Value { value: item.1 })?)),
None => Ok(None),
}
}
}
struct ValueEnum<'de> {
value: &'de str,
}
impl<'de> de::EnumAccess<'de> for ValueEnum<'de> {
type Error = de::value::Error;
type Variant = UnitVariant;
fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Self::Error>
where
V: de::DeserializeSeed<'de>,
{
Ok((seed.deserialize(Key { key: self.value })?, UnitVariant))
}
}
struct UnitVariant;
impl<'de> de::VariantAccess<'de> for UnitVariant {
type Error = de::value::Error;
fn unit_variant(self) -> Result<(), Self::Error> {
Ok(())
}
fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value, Self::Error>
where
T: de::DeserializeSeed<'de>,
{
Err(de::value::Error::custom("not supported"))
}
fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom("not supported"))
}
fn struct_variant<V>(
self,
_: &'static [&'static str],
_: V,
) -> Result<V::Value, Self::Error>
where
V: Visitor<'de>,
{
Err(de::value::Error::custom("not supported"))
}
}
#[cfg(test)]
mod tests {
use serde::de;
use serde_derive::Deserialize;
use super::*;
use crate::path::{Path, PathItem};
#[derive(Deserialize)]
struct MyStruct {
key: String,
value: String,
}
#[derive(Deserialize)]
struct Id {
_id: String,
}
#[derive(Debug, Deserialize)]
struct Test1(String, u32);
#[derive(Debug, Deserialize)]
struct Test2 {
key: String,
value: u32,
}
#[derive(Debug, Deserialize, PartialEq)]
#[serde(rename_all = "lowercase")]
enum TestEnum {
Val1,
Val2,
}
#[derive(Debug, Deserialize)]
struct Test3 {
val: TestEnum,
}
#[test]
#[allow(clippy::let_unit_value, clippy::unit_cmp)]
fn test_request_extract() {
let mut path = Path::new("/name/user1/");
path.segments = vec![
("key", PathItem::Static("name")),
("value", PathItem::Static("user1")),
];
let s: () = de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s, ());
let s: MyStruct =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s.key, "name");
assert_eq!(s.value, "user1");
let s: MyStruct = path.load().unwrap();
assert_eq!(s.key, "name");
assert_eq!(s.value, "user1");
let s: (String, String) =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s.0, "name");
assert_eq!(s.1, "user1");
let s: &str =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s, "name");
let mut path = Path::new("/name/user1/");
path.segments = vec![
("key", PathItem::Static("name")),
("value", PathItem::Static("32")),
];
let s: Test1 =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s.0, "name");
assert_eq!(s.1, 32);
#[derive(Deserialize)]
struct T(Test1);
let s: T = de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!((s.0).0, "name");
assert_eq!((s.0).1, 32);
let s: Test2 =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s.key, "name");
assert_eq!(s.value, 32);
let s: Result<(Test2,), _> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
let s: (String, u8) =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(s.0, "name");
assert_eq!(s.1, 32);
let res: Vec<String> =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(res[0], "name".to_owned());
assert_eq!(res[1], "32".to_owned());
#[derive(Debug, Deserialize)]
struct S2(());
let s: Result<S2, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_ok());
let s: Result<(), de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_ok());
let s: Result<(String, ()), de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_ok());
}
#[test]
fn test_extract_path_single() {
let mut path = Path::new("/name/user1/");
path.segments = vec![("value", PathItem::Static("32"))];
let i: i8 = de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(i, 32);
let i: (i8,) =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(i, (32,));
let i: Result<(i8, i8), _> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(i.is_err());
#[derive(Deserialize)]
struct Test(i8);
let i: Test =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(i.0, 32);
path.segments.push(("value2", PathItem::Static("32")));
let i: Result<i8, _> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(i.is_err());
}
#[test]
fn test_extract_enum() {
let mut path = Path::new("/val1/");
path.segments = vec![("val", PathItem::Static("val1"))];
let i: TestEnum =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(i, TestEnum::Val1);
let mut path = Path::new("/val1/");
path.segments = vec![
("val1", PathItem::Static("val1")),
("val2", PathItem::Static("val2")),
];
let i: (TestEnum, TestEnum) =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(i, (TestEnum::Val1, TestEnum::Val2));
}
#[test]
fn test_extract_enum_value() {
let mut path = Path::new("/val1/");
path.segments = vec![("val", PathItem::Static("val1"))];
let i: Test3 =
de::Deserialize::deserialize(PathDeserializer::new(&path)).unwrap();
assert_eq!(i.val, TestEnum::Val1);
let mut path = Path::new("/val3/");
path.segments = vec![("val", PathItem::Static("val3"))];
let i: Result<Test3, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(i.is_err());
assert!(format!("{:?}", i).contains("unknown variant"));
}
#[test]
fn test_extract_errors() {
let mut path = Path::new("/name/");
path.segments = vec![("value", PathItem::Static("name"))];
let s: Result<Test1, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("wrong number of parameters"));
let s: Result<Test2, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("can not parse"));
let s: Result<(String, String), de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("wrong number of parameters"));
let s: Result<u32, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("can not parse"));
#[derive(Debug, Deserialize)]
struct S {
inner: (String,),
}
let s: Result<S, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("missing field `inner`"));
let path = Path::new("");
let s: Result<&str, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("wrong number of parameters: 0 expected 1"));
let s: Result<TestEnum, de::value::Error> =
de::Deserialize::deserialize(PathDeserializer::new(&path));
assert!(s.is_err());
assert!(format!("{:?}", s).contains("expeceted at least one parameters"));
}
}