xml: Fix dumb bug where default value would be evaluated and panic even when not needed

crates/xml/derive/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "xml_derive"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [lib]
 proc-macro = true

crates/xml/derive/src/attrs.rs

@@ -1,9 +1,9 @@
 use std::collections::HashMap;
 
-use darling::{util::Flag, FromDeriveInput, FromField, FromMeta, FromVariant};
+use darling::{FromDeriveInput, FromField, FromMeta, FromVariant, util::Flag};
 use syn::LitByteStr;
 
-#[derive(Default, FromMeta, Clone)]
+#[derive(Debug, Default, FromMeta, Clone)]
 pub struct TagAttrs {
     pub rename: Option<LitByteStr>,
     pub ns: Option<syn::Path>,
@@ -35,7 +35,7 @@ pub struct StructAttrs {
     pub allow_invalid: Flag,
 }
 
-#[derive(Default, FromMeta, PartialEq)]
+#[derive(Debug, Default, FromMeta, PartialEq)]
 pub enum FieldType {
     #[default]
     Tag,
@@ -46,7 +46,7 @@ pub enum FieldType {
     Namespace,
 }
 
-#[derive(Default, FromField)]
+#[derive(Debug, Default, FromField)]
 #[darling(attributes(xml))]
 pub struct FieldAttrs {
     #[darling(flatten)]

crates/xml/derive/src/field.rs

@@ -4,8 +4,8 @@ use super::{
 };
 use darling::FromField;
 use heck::ToKebabCase;
-use quote::quote;
 use quote::ToTokens;
+use quote::quote;
 use syn::spanned::Spanned;
 
 fn wrap_option_if_no_default(
@@ -36,13 +36,15 @@ impl Field {
 
     /// Field name in XML
     pub fn xml_name(&self) -> syn::LitByteStr {
-        self.attrs.common.rename.to_owned().unwrap_or({
+        if let Some(rename) = self.attrs.common.rename.to_owned() {
+            rename
+        } else {
             let ident = self
                 .field_ident()
                 .as_ref()
                 .expect("unnamed tag fields need a rename attribute");
             syn::LitByteStr::new(ident.to_string().to_kebab_case().as_bytes(), ident.span())
-        })
+        }
     }
 
     /// Field identifier

crates/xml/tests/se_struct.rs

@@ -3,8 +3,8 @@ use std::{
     collections::HashMap,
 };
 
-use quick_xml::name::Namespace;
 use quick_xml::Writer;
+use quick_xml::name::Namespace;
 use rustical_xml::{XmlDocument, XmlRootTag, XmlSerialize, XmlSerializeRoot};
 use xml_derive::XmlDeserialize;
 
@@ -196,7 +196,6 @@ fn test_struct_tag_list() {
 
 #[test]
 fn test_struct_ns() {
-    // const NS: Namespace = Namespace(b"TEST", quick_xml::name::Namespace(b"NS:TEST:"));
     const NS: Namespace = quick_xml::name::Namespace(b"NS:TEST:");
 
     #[derive(Debug, XmlRootTag, XmlSerialize)]
@@ -239,3 +238,20 @@ fn test_struct_tuple() {
     let out = String::from_utf8(buf).unwrap();
     dbg!(out);
 }
+
+#[test]
+fn test_tuple_struct() {
+    const NS: Namespace = quick_xml::name::Namespace(b"NS:TEST:");
+
+    #[derive(Debug, XmlRootTag, XmlSerialize)]
+    #[xml(root = b"document")]
+    struct Document(#[xml(ns = "NS", rename = b"okay")] String);
+
+    let mut buf = Vec::new();
+    let mut writer = quick_xml::Writer::new(&mut buf);
+    Document("hello!".to_string())
+        .serialize_root(&mut writer)
+        .unwrap();
+    let out = String::from_utf8(buf).unwrap();
+    dbg!(out);
+}