Read all Serde attributes in settings

foundations-macros/src/settings.rs

@@ -82,11 +82,20 @@ struct SerdeArgs {
 
 impl SerdeArgs {
     fn parse_from_attrs(attrs: &[Attribute]) -> Result<Option<Self>> {
-        let Some(attr) = attrs.iter().find(|a| a.path().is_ident("serde")) else {
+        let mut serde_attrs = attrs
+            .iter()
+            .filter(|a| a.path().is_ident("serde"))
+            .peekable();
+        if serde_attrs.peek().is_none() {
             return Ok(None);
-        };
+        }
+
+        let mut meta_list = Vec::new();
+        for attr in serde_attrs {
+            meta_list.extend(attr.parse_args_with(|input: ParseStream| parse_meta_list(&input))?);
+        }
 
-        Ok(Some(Self::from_meta(&attr.meta)?))
+        Ok(Some(Self::from_list(&meta_list)?))
     }
 }
 

foundations/tests/settings.rs

@@ -8,6 +8,7 @@ struct NestedStruct {
     a: usize,
     /// multi-line
     /// doc comment
+    #[serde(alias = "legacy_b")]
     #[serde(default = "NestedStruct::default_b")]
     b: u32,
     // no doc comment at all
@@ -42,6 +43,7 @@ struct NestedDup {
 struct FlattenedStruct {
     /// Doc comments on flattened members itself
     /// should not appear on the output.
+    #[serde(default)]
     #[serde(flatten)]
     inner: NestedStruct,
     /// Another field that isn't flattened.
@@ -262,6 +264,9 @@ fn defaults() {
     assert_eq!(simple_struct.b, 0xb);
     assert_eq!(simple_struct.c, 0);
 
+    let aliased_struct = from_yaml_str::<NestedStruct>("legacy_b: 123").unwrap();
+    assert_eq!(aliased_struct.b, 123);
+
     let nested_struct = from_yaml_str::<SimpleStruct>("---\nx: 1").unwrap();
 
     assert_eq!(nested_struct.inner.b, 0xb);