Provide more context in DuplicateValue errors

instant-xml-macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "instant-xml-macros"
-version = "0.4.2"
+version = "0.5.0"
 edition = "2021"
 rust-version = "1.61"
 workspace = ".."

instant-xml-macros/src/de.rs

@@ -94,7 +94,7 @@ fn deserialize_scalar_enum(
                 use ::instant_xml::Error;
 
                 if into.is_some() {
-                    return Err(Error::DuplicateValue);
+                    return Err(Error::DuplicateValue(field));
                 }
 
                 let cow_str = match deserializer.take_str()? {

instant-xml/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "instant-xml"
-version = "0.4.0"
+version = "0.5.0"
 edition = "2021"
 rust-version = "1.61"
 workspace = ".."
@@ -12,7 +12,7 @@ readme = "../README.md"
 
 [dependencies]
 chrono = { version = "0.4.23", optional = true }
-macros = { package = "instant-xml-macros", version = "0.4.0", path = "../instant-xml-macros" }
+macros = { package = "instant-xml-macros", version = "0.5.0", path = "../instant-xml-macros" }
 thiserror = "1.0.29"
 xmlparser = "0.13.3"
 

instant-xml/src/de.rs

@@ -363,11 +363,11 @@ impl<'xml> Iterator for Context<'xml> {
 
 pub fn borrow_cow_str<'a, 'xml: 'a>(
     into: &mut CowStrAccumulator<'xml, 'a>,
-    _: &'static str,
+    field: &'static str,
     deserializer: &mut Deserializer<'_, 'xml>,
 ) -> Result<(), Error> {
     if into.inner.is_some() {
-        return Err(Error::DuplicateValue);
+        return Err(Error::DuplicateValue(field));
     }
 
     match deserializer.take_str()? {
@@ -381,11 +381,11 @@ pub fn borrow_cow_str<'a, 'xml: 'a>(
 
 pub fn borrow_cow_slice_u8<'xml>(
     into: &mut Option<Cow<'xml, [u8]>>,
-    _: &'static str,
+    field: &'static str,
     deserializer: &mut Deserializer<'_, 'xml>,
 ) -> Result<(), Error> {
     if into.is_some() {
-        return Err(Error::DuplicateValue);
+        return Err(Error::DuplicateValue(field));
     }
 
     if let Some(value) = deserializer.take_str()? {

instant-xml/src/impls.rs

@@ -13,11 +13,12 @@ use crate::{Accumulate, Deserializer, Error, FromXml, Id, Kind, Serializer, ToXm
 // Deserializer
 
 pub fn from_xml_str<T: FromStr>(
-    deserializer: &mut Deserializer<'_, '_>,
     into: &mut Option<T>,
+    field: &'static str,
+    deserializer: &mut Deserializer<'_, '_>,
 ) -> Result<(), Error> {
     if into.is_some() {
-        return Err(Error::DuplicateValue);
+        return Err(Error::DuplicateValue(field));
     }
 
     let value = match deserializer.take_str()? {
@@ -54,7 +55,7 @@ impl<'xml, T: FromStr> FromXml<'xml> for FromXmlStr<T> {
         deserializer: &mut Deserializer<'_, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let value = match deserializer.take_str()? {
@@ -93,7 +94,7 @@ impl<'xml> FromXml<'xml> for bool {
         deserializer: &mut Deserializer<'cx, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let value = match deserializer.take_str()? {
@@ -189,7 +190,7 @@ macro_rules! from_xml_for_number {
                 deserializer: &mut Deserializer<'cx, 'xml>,
             ) -> Result<(), Error> {
                 if into.is_some() {
-                    return Err(Error::DuplicateValue);
+                    return Err(Error::DuplicateValue(field));
                 }
 
                 let mut value = None;
@@ -235,7 +236,7 @@ impl<'xml> FromXml<'xml> for char {
         deserializer: &mut Deserializer<'cx, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let mut value = None;
@@ -262,11 +263,11 @@ impl<'xml> FromXml<'xml> for String {
 
     fn deserialize<'cx>(
         into: &mut Self::Accumulator,
-        _: &'static str,
+        field: &'static str,
         deserializer: &mut Deserializer<'cx, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         match deserializer.take_str()? {
@@ -292,11 +293,11 @@ impl<'xml, 'a> FromXml<'xml> for Cow<'a, str> {
 
     fn deserialize(
         into: &mut Self::Accumulator,
-        _: &'static str,
+        field: &'static str,
         deserializer: &mut Deserializer<'_, 'xml>,
     ) -> Result<(), Error> {
         if into.inner.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let value = match deserializer.take_str()? {
@@ -595,11 +596,11 @@ impl<'xml> FromXml<'xml> for DateTime<Utc> {
 
     fn deserialize<'cx>(
         into: &mut Self::Accumulator,
-        _: &'static str,
+        field: &'static str,
         deserializer: &mut Deserializer<'cx, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let value = match deserializer.take_str()? {
@@ -657,11 +658,11 @@ impl<'xml> FromXml<'xml> for NaiveDate {
 
     fn deserialize<'cx>(
         into: &mut Self::Accumulator,
-        _: &'static str,
+        field: &'static str,
         deserializer: &mut Deserializer<'cx, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let value = match deserializer.take_str()? {
@@ -729,7 +730,7 @@ impl<'xml> FromXml<'xml> for IpAddr {
         deserializer: &mut Deserializer<'cx, 'xml>,
     ) -> Result<(), Error> {
         if into.is_some() {
-            return Err(Error::DuplicateValue);
+            return Err(Error::DuplicateValue(field));
         }
 
         let mut value = None;

instant-xml/src/lib.rs

@@ -151,8 +151,8 @@ pub enum Error {
     UnexpectedState(&'static str),
     #[error("expected scalar, found {0}")]
     ExpectedScalar(String),
-    #[error("duplicate value")]
+    #[error("duplicate value for {0}")]
-    DuplicateValue,
+    DuplicateValue(&'static str),
 }
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]