Fixed tests after modifying TypeErrors originating from structs. Started work on TypeError message on Enums

pyo3-macros-backend/src/from_pyobject.rs

@@ -58,9 +58,13 @@ impl<'a> Enum<'a> {
                 let maybe_ret = || -> pyo3::PyResult<Self> {
                     #struct_derive
                 }();
+
                 if maybe_ret.is_ok() {
                     return maybe_ret
                 }
+                if let Err(inner) = maybe_ret {
+                    err_reasons.push(format!("{}", inner))
+                }
             );
 
             var_extracts.push(ext);
@@ -74,13 +78,16 @@ impl<'a> Enum<'a> {
         } else {
             error_names
         };
+        let ty_name: String = self.enum_ident.to_string();
         quote!(
+            let mut err_reasons: Vec<String> = Vec::new();
             #(#var_extracts)*
             let type_name = obj.get_type().name()?;
-            let err_msg = format!("In {} : '{}' object cannot be converted to '{}'",
-                self.enum_ident,
+            let err_msg = format!("Failed to extract type {}\n\nCaused by:\nTypeError: '{}' object cannot be converted to '{}'",
+                #ty_name,
                 type_name,
                 #error_names);
+            println!("{:?}", err_reasons);
             Err(pyo3::exceptions::PyTypeError::new_err(err_msg))
         )
     }

tests/test_frompyobject.rs

@@ -296,7 +296,7 @@ fn test_err_rename() {
     assert!(f.is_err());
     assert_eq!(
         f.unwrap_err().to_string(),
-        "TypeError: 'dict' object cannot be converted to 'Union[str, uint, int]'"
+        "TypeError: Failed to extract type Bar\n\nCaused by:\nTypeError: 'dict' object cannot be converted to 'Union[str, uint, int]'"
     );
 }
 

tests/ui/invalid_frompy_derive.stderr

@@ -84,7 +84,7 @@ error: transparent structs and variants can only have 1 field
 70 | |     },
    | |_____^
 
-error: expected one of: `attribute`, `item`, `from_py_with`
+error: expected one of: `attribute`, `item`, `from_py_with`, `conversion_error`
   --> $DIR/invalid_frompy_derive.rs:76:12
    |
 76 |     #[pyo3(attr)]