Add contractevent macro and event support to contract spec

soroban-sdk-macros/Cargo.toml

@@ -26,6 +26,7 @@ itertools = "0.10.5"
 darling = "0.20.10"
 macro-string = "0.1.4"
 sha2 = "0.10.7"
+heck = "0.5.0"
 
 [features]
 testutils = []

soroban-sdk-macros/src/attribute.rs

@@ -1,4 +1,4 @@
-use syn::Attribute;
+use syn::{punctuated::Punctuated, Attribute, Data, Fields, FieldsNamed, FieldsUnnamed};
 
 /// Returns true if the attribute is an attribute that should be preserved and
 /// passed through to code generated for the item the attribute is on.
@@ -8,3 +8,84 @@ pub fn pass_through_attr_to_gen_code(attr: &Attribute) -> bool {
         || attr.path().is_ident("allow")
         || attr.path().is_ident("deny")
 }
+
+/// Modifies the input, removing any attributes on struct fields that match the attrs name list.
+///
+/// Currently implemented only for struct data.
+pub fn remove_attributes_from_item(data: &mut Data, attrs: &[&str]) {
+    let fields = match data {
+        Data::Struct(data) => match &mut data.fields {
+            Fields::Named(FieldsNamed { named, .. }) => named,
+            Fields::Unnamed(FieldsUnnamed { unnamed, .. }) => unnamed,
+            Fields::Unit => &mut Punctuated::default(), // Unit structs have no fields, nothing to do.
+        },
+        _ => unimplemented!("Only structs are supported by remove_attributes_from_item"),
+    };
+    for field in fields {
+        field.attrs.retain(|attr| {
+            !attr
+                .path()
+                .get_ident()
+                .is_some_and(|ident| attrs.contains(&ident.to_string().as_str()))
+        });
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use quote::{quote, ToTokens};
+    use syn::DeriveInput;
+
+    use super::remove_attributes_from_item;
+
+    #[test]
+    fn test_remove_attributes_from_item_struct_named() {
+        let input = quote! {
+            struct Struct {
+                f1: u32,
+                #[topic]
+                f2: u32,
+                f3: u32,
+                #[data]
+                f4: u32,
+            }
+        };
+        let expect = quote! {
+            struct Struct {
+                f1: u32,
+                f2: u32,
+                f3: u32,
+                f4: u32,
+            }
+        };
+        let mut input = syn::parse2::<DeriveInput>(input.into()).unwrap();
+        remove_attributes_from_item(&mut input.data, &["topic", "data"]);
+        assert_eq!(input.to_token_stream().to_string(), expect.to_string());
+    }
+
+    #[test]
+    fn test_remove_attributes_from_item_struct_unnamed() {
+        let input = quote! {
+            struct Struct(#[topic] u32, u32, #[data] u64);
+        };
+        let expect = quote! {
+            struct Struct(u32, u32, u64);
+        };
+        let mut input = syn::parse2::<DeriveInput>(input.into()).unwrap();
+        remove_attributes_from_item(&mut input.data, &["topic", "data"]);
+        assert_eq!(input.to_token_stream().to_string(), expect.to_string());
+    }
+
+    #[test]
+    fn test_remove_attributes_from_item_struct_unit() {
+        let input = quote! {
+            struct Struct;
+        };
+        let expect = quote! {
+            struct Struct;
+        };
+        let mut input = syn::parse2::<DeriveInput>(input.into()).unwrap();
+        remove_attributes_from_item(&mut input.data, &["topic", "data"]);
+        assert_eq!(input.to_token_stream().to_string(), expect.to_string());
+    }
+}