refactor: make MethodError wrap TransformError

3 files changed, 25 insertions, 22 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 1fd5988..02b150e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -44,6 +44,7 @@ use crate::parse_trait_sig::SignatureChanges;
 use crate::parse_trait_sig::TypeTransform;
 use crate::syn_utils::iter_path;
 use crate::syn_utils::trait_bounds;
+use crate::transform::TransformError;
 use crate::transform::TypeConverter;
 
 mod parse_assoc_type;
@@ -95,7 +96,7 @@ pub fn dynamize(_attr: TokenStream, input: TokenStream) -> TokenStream {
             let mut signature = method.sig.clone();
             match parse_trait_signature(&mut signature, &type_converter) {
                 Err((_, MethodError::NonDispatchableMethod)) => continue,
-                Err((span, MethodError::AssocTypeWithoutDestType)) => {
+                Err((span, MethodError::Transform(TransformError::AssocTypeWithoutDestType))) => {
                     return abort!(
                         span,
                         "associated type is either undefined or doesn't have a trait bound"
@@ -107,7 +108,7 @@ pub fn dynamize(_attr: TokenStream, input: TokenStream) -> TokenStream {
                         "dynamize does not support associated types in parameter types"
                     )
                 }
-                Err((span, MethodError::UnsupportedType)) => {
+                Err((span, MethodError::Transform(TransformError::UnsupportedType))) => {
                     return abort!(span, "dynamize does not know how to convert this type")
                 }
                 Err((span, MethodError::UnconvertedAssocType)) => {
diff --git a/src/parse_trait_sig.rs b/src/parse_trait_sig.rs
index aff4fe9..dfe3ce7 100644
--- a/src/parse_trait_sig.rs
+++ b/src/parse_trait_sig.rs
@@ -28,13 +28,17 @@ pub enum MethodError {
     AssocTypeInInputs,
     ImplTraitInInputs,
 
-    // TODO: wrap TransformError
-    AssocTypeWithoutDestType,
-    UnsupportedType,
+    Transform(TransformError),
 
     UnconvertedAssocType,
 }
 
+impl From<TransformError> for MethodError {
+    fn from(err: TransformError) -> Self {
+        Self::Transform(err)
+    }
+}
+
 fn filter_map_impl_trait(item: TypeOrPath) -> Option<&TypeImplTrait> {
     match item {
         TypeOrPath::Type(Type::ImplTrait(impltrait)) => Some(impltrait),
@@ -72,11 +76,8 @@ pub fn parse_trait_signature(
     let return_type = match &mut signature.output {
         ReturnType::Type(_, og_type) => match type_converter.convert_type(og_type) {
             Ok(ret_type) => ret_type,
-            Err((span, TransformError::AssocTypeWithoutDestType)) => {
-                return Err((span, MethodError::AssocTypeWithoutDestType));
-            }
-            Err((span, TransformError::UnsupportedType)) => {
-                return Err((span, MethodError::UnsupportedType));
+            Err((span, err)) => {
+                return Err((span, err.into()));
             }
         },
         ReturnType::Default => TypeTransform::NoOp,
@@ -144,7 +145,7 @@ mod tests {
     use crate::{
         parse_assoc_type::DestType,
         parse_trait_sig::{parse_trait_signature, MethodError, SignatureChanges, TypeTransform},
-        transform::TypeConverter,
+        transform::{TransformError, TypeConverter},
     };
 
     #[test]
@@ -194,7 +195,10 @@ mod tests {
 
         assert!(matches!(
             parse_trait_signature(&mut type1.sig, &Default::default()),
-            Err((_, MethodError::AssocTypeWithoutDestType))
+            Err((
+                _,
+                MethodError::Transform(TransformError::AssocTypeWithoutDestType)
+            ))
         ));
     }
 
@@ -259,7 +263,7 @@ mod tests {
 
         assert!(matches!(
             parse_trait_signature(&mut type1.sig, &Default::default()),
-            Err((_, MethodError::UnsupportedType))
+            Err((_, MethodError::Transform(TransformError::UnsupportedType)))
         ));
     }
 
@@ -272,7 +276,7 @@ mod tests {
 
         assert!(matches!(
             parse_trait_signature(&mut type1.sig, &Default::default()),
-            Err((_, MethodError::UnsupportedType))
+            Err((_, MethodError::Transform(TransformError::UnsupportedType)))
         ));
     }
 
@@ -285,7 +289,7 @@ mod tests {
 
         assert!(matches!(
             parse_trait_signature(&mut type1.sig, &Default::default()),
-            Err((_, MethodError::UnsupportedType))
+            Err((_, MethodError::Transform(TransformError::UnsupportedType)))
         ));
     }
 
@@ -298,7 +302,7 @@ mod tests {
 
         assert!(matches!(
             parse_trait_signature(&mut type1.sig, &Default::default()),
-            Err((_, MethodError::UnsupportedType))
+            Err((_, MethodError::Transform(TransformError::UnsupportedType)))
         ));
     }
 
@@ -350,7 +354,7 @@ mod tests {
 
         assert!(matches!(
             parse_trait_signature(&mut type1.sig, &Default::default()),
-            Err((_, MethodError::UnsupportedType))
+            Err((_, MethodError::Transform(TransformError::UnsupportedType)))
         ));
     }
 }
diff --git a/src/transform.rs b/src/transform.rs
index 13cf519..4649037 100644
--- a/src/transform.rs
+++ b/src/transform.rs
@@ -19,6 +19,7 @@ pub struct TypeConverter<'a> {
     pub assoc_type_conversions: HashMap<Ident, DestType<'a>>,
 }
 
+#[derive(Debug)]
 pub enum TransformError {
     AssocTypeWithoutDestType,
     UnsupportedType,
@@ -237,11 +238,8 @@ fn dynamize_trait_bound(
                         Ok(ret_type) => {
                             transforms.push(ret_type);
                         }
-                        Err((span, TransformError::AssocTypeWithoutDestType)) => {
-                            return Err((span, MethodError::AssocTypeWithoutDestType));
-                        }
-                        Err((span, TransformError::UnsupportedType)) => {
-                            return Err((span, MethodError::UnsupportedType));
+                        Err((span, err)) => {
+                            return Err((span, err.into()));
                         }
                     }
                 }