feat(serde): Publicly expose toml_edit's ser::Error variants

crates/toml_edit/src/ser/key.rs

@@ -1,6 +1,6 @@
 use crate::InternalString;
 
-use super::{Error, ErrorKind};
+use super::Error;
 
 pub(crate) struct KeySerializer;
 
@@ -16,78 +16,78 @@ impl serde::ser::Serializer for KeySerializer {
     type SerializeStructVariant = serde::ser::Impossible<InternalString, Error>;
 
     fn serialize_bool(self, _v: bool) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_i8(self, _v: i8) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_i16(self, _v: i16) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_i32(self, _v: i32) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_i64(self, _v: i64) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_u8(self, _v: u8) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_u16(self, _v: u16) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_u32(self, _v: u32) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_u64(self, _v: u64) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_f32(self, _v: f32) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_f64(self, _v: f64) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_char(self, _v: char) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_str(self, value: &str) -> Result<InternalString, Self::Error> {
         Ok(InternalString::from(value))
     }
 
     fn serialize_bytes(self, _value: &[u8]) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_none(self) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<InternalString, Self::Error>
     where
         T: serde::ser::Serialize,
     {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_unit(self) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_unit_struct(self, _name: &'static str) -> Result<InternalString, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_unit_variant(
@@ -120,23 +120,23 @@ impl serde::ser::Serializer for KeySerializer {
     where
         T: serde::ser::Serialize,
     {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_tuple_struct(
         self,
         _name: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeTupleStruct, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_tuple_variant(
@@ -146,19 +146,19 @@ impl serde::ser::Serializer for KeySerializer {
         _variant: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeTupleVariant, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_struct(
         self,
         _name: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeStruct, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 
     fn serialize_struct_variant(
@@ -168,6 +168,6 @@ impl serde::ser::Serializer for KeySerializer {
         _variant: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeStructVariant, Self::Error> {
-        Err(ErrorKind::KeyNotString.into())
+        Err(Error::KeyNotString)
     }
 }

crates/toml_edit/src/ser/mod.rs

@@ -16,18 +16,24 @@ use crate::visit_mut::VisitMut;
 
 /// Errors that can occur when deserializing a type.
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Error {
-    kind: ErrorKind,
+#[non_exhaustive]
+pub enum Error {
+    /// Type could not be serialized to TOML
+    UnsupportedType(Option<&'static str>),
+    /// `None` could not be serialized to TOML
+    UnsupportedNone,
+    /// Key was not convertable to `String` for serializing to TOML
+    KeyNotString,
+    /// Other serialization error
+    Custom(String),
 }
 
 impl Error {
     pub(crate) fn custom<T>(msg: T) -> Self
     where
         T: std::fmt::Display,
     {
-        Error {
-            kind: ErrorKind::Custom(msg.to_string()),
-        }
+        Error::Custom(msg.to_string())
     }
 }
 
@@ -42,7 +48,13 @@ impl serde::ser::Error for Error {
 
 impl std::fmt::Display for Error {
     fn fmt(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        self.kind.fmt(formatter)
+        match self {
+            Self::UnsupportedType(Some(t)) => write!(formatter, "unsupported {t} type"),
+            Self::UnsupportedType(None) => write!(formatter, "unsupported rust type"),
+            Self::UnsupportedNone => "unsupported None value".fmt(formatter),
+            Self::KeyNotString => "map key was not a string".fmt(formatter),
+            Self::Custom(s) => s.fmt(formatter),
+        }
     }
 }
 
@@ -60,32 +72,6 @@ impl From<Error> for crate::TomlError {
 
 impl std::error::Error for Error {}
 
-impl From<ErrorKind> for Error {
-    fn from(kind: ErrorKind) -> Self {
-        Self { kind }
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-enum ErrorKind {
-    UnsupportedType(Option<&'static str>),
-    UnsupportedNone,
-    KeyNotString,
-    Custom(String),
-}
-
-impl std::fmt::Display for ErrorKind {
-    fn fmt(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        match self {
-            ErrorKind::UnsupportedType(Some(t)) => write!(formatter, "unsupported {t} type"),
-            ErrorKind::UnsupportedType(None) => write!(formatter, "unsupported rust type"),
-            ErrorKind::UnsupportedNone => "unsupported None value".fmt(formatter),
-            ErrorKind::KeyNotString => "map key was not a string".fmt(formatter),
-            ErrorKind::Custom(s) => s.fmt(formatter),
-        }
-    }
-}
-
 /// Serialize the given data structure as a TOML byte vector.
 ///
 /// Serialization can fail if `T`'s implementation of `Serialize` decides to
@@ -165,7 +151,7 @@ where
     let item = crate::Item::Value(value);
     let root = item
         .into_table()
-        .map_err(|_| ErrorKind::UnsupportedType(None))?;
+        .map_err(|_| Error::UnsupportedType(None))?;
     Ok(root.into())
 }
 

crates/toml_edit/src/ser/table.rs

@@ -1,4 +1,4 @@
-use super::{Error, ErrorKind, KeySerializer};
+use super::{Error, KeySerializer};
 
 #[doc(hidden)]
 pub struct SerializeValueTable {
@@ -114,7 +114,7 @@ impl serde::ser::SerializeMap for SerializeKeyValuePairs {
                 self.items.insert(key, kv);
             }
             Err(e) => {
-                if e.kind != ErrorKind::UnsupportedNone {
+                if e != Error::UnsupportedNone {
                     return Err(e);
                 }
             }
@@ -149,7 +149,7 @@ impl serde::ser::SerializeStruct for SerializeKeyValuePairs {
                 self.items.insert(crate::InternalString::from(key), kv);
             }
             Err(e) => {
-                if e.kind != ErrorKind::UnsupportedNone {
+                if e != Error::UnsupportedNone {
                     return Err(e);
                 }
             }

crates/toml_edit/src/ser/value.rs

@@ -1,4 +1,4 @@
-use super::{Error, ErrorKind};
+use super::Error;
 
 /// Serialization implementation for TOML.
 ///
@@ -90,7 +90,7 @@ impl serde::ser::Serializer for ValueSerializer {
     }
 
     fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
-        Err(ErrorKind::UnsupportedNone.into())
+        Err(Error::UnsupportedNone)
     }
 
     fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
@@ -101,11 +101,11 @@ impl serde::ser::Serializer for ValueSerializer {
     }
 
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(ErrorKind::UnsupportedType(Some("unit")).into())
+        Err(Error::UnsupportedType(Some("unit")))
     }
 
     fn serialize_unit_struct(self, name: &'static str) -> Result<Self::Ok, Self::Error> {
-        Err(ErrorKind::UnsupportedType(Some(name)).into())
+        Err(Error::UnsupportedType(Some(name)))
     }
 
     fn serialize_unit_variant(
@@ -138,7 +138,7 @@ impl serde::ser::Serializer for ValueSerializer {
     where
         T: serde::ser::Serialize,
     {
-        Err(ErrorKind::UnsupportedType(Some(name)).into())
+        Err(Error::UnsupportedType(Some(name)))
     }
 
     fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
@@ -194,6 +194,6 @@ impl serde::ser::Serializer for ValueSerializer {
         _variant: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeStructVariant, Self::Error> {
-        Err(ErrorKind::UnsupportedType(Some(name)).into())
+        Err(Error::UnsupportedType(Some(name)))
     }
 }