compat fix for test_field_metadata_custom_mapping in test_dataclasses.py

hydrogen602 · youknowone · commit 6c37e8f4e75a · 2024-04-17T21:52:10.000+09:00
diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py
@@ -1843,8 +1843,6 @@ class C:
                                     'does not support item assignment'):
             fields(C)[0].metadata['test'] = 3
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_field_metadata_custom_mapping(self):
         # Try a custom mapping.
         class SimpleNameSpace:
diff --git a/vm/src/builtins/mappingproxy.rs b/vm/src/builtins/mappingproxy.rs
@@ -93,13 +93,12 @@ impl Constructor for PyMappingProxy {
 ))]
 impl PyMappingProxy {
     fn get_inner(&self, key: PyObjectRef, vm: &VirtualMachine) -> PyResult<Option<PyObjectRef>> {
-        let opt = match &self.mapping {
-            MappingProxyInner::Class(class) => key
+        match &self.mapping {
+            MappingProxyInner::Class(class) => Ok(key
                 .as_interned_str(vm)
-                .and_then(|key| class.attributes.read().get(key).cloned()),
-            MappingProxyInner::Mapping(mapping) => mapping.mapping().subscript(&*key, vm).ok(),
-        };
-        Ok(opt)
+                .and_then(|key| class.attributes.read().get(key).cloned())),
+            MappingProxyInner::Mapping(mapping) => mapping.mapping().subscript(&*key, vm).map(Some),
+        }
     }
 
     #[pymethod]
