It's nicer to have the check that the class is there yet earlier as it's state related.

It's still going to need revision later as it depends on state modification to work. The
class should only be modified once it is explicitly registered.

Author: faassen

crates/macros/src/impl_.rs

@@ -96,24 +96,13 @@ pub enum PropAttrTy {
 }
 
 // note: this takes a mutable argument as it mutates a class
-fn prepare(
-    args: AttrArgs,
-    input: ItemImpl,
-    classes: &mut HashMap<String, Class>,
-) -> Result<TokenStream> {
+fn prepare(args: AttrArgs, input: ItemImpl, class: &mut Class) -> Result<TokenStream> {
     let ItemImpl { self_ty, items, .. } = input;
-    let class_name = self_ty.to_token_stream().to_string();
 
     if input.trait_.is_some() {
         bail!("This macro cannot be used on trait implementations.");
     }
 
-    let class = classes.get_mut(&class_name).ok_or_else(|| {
-        anyhow!(
-            "You must use `#[php_class]` on the struct before using this attribute on the impl."
-        )
-    })?;
-
     let tokens = items
         .into_iter()
         .map(|item| {
@@ -185,7 +174,15 @@ pub fn parser(args: AttributeArgs, input: ItemImpl) -> Result<TokenStream> {
         );
     }
 
-    prepare(args, input, &mut state.classes)
+    let class_name = input.self_ty.to_token_stream().to_string();
+
+    let class = state.classes.get_mut(&class_name).ok_or_else(|| {
+        anyhow!(
+            "You must use `#[php_class]` on the struct before using this attribute on the impl."
+        )
+    })?;
+
+    prepare(args, input, class)
 }
 
 pub fn parse_attribute(attr: &Attribute) -> Result<Option<ParsedAttribute>> {