Merge pull request RustPython#3731 from CHOUMnote/addWeakProxyStr

Add weak proxy str

Author: youknowone

Lib/test/test_deque.py

@@ -889,8 +889,6 @@ def test_pickle_recursive(self):
             for d in DequeWithBadIter('abc'), DequeWithBadIter('abc', 2):
                 self.assertRaises(TypeError, pickle.dumps, d, proto)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_weakref(self):
         d = deque('gallahad')
         p = weakref.proxy(d)

Lib/test/test_set.py

@@ -613,8 +613,6 @@ def test_inplace_on_self(self):
         t ^= t
         self.assertEqual(t, self.thetype())
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_weakref(self):
         s = self.thetype('gallahad')
         p = weakref.proxy(s)

vm/src/builtins/weakproxy.rs

@@ -62,14 +62,23 @@ impl PyWeakProxy {
     // TODO: callbacks
     #[pymethod(magic)]
     fn getattr(&self, attr_name: PyStrRef, vm: &VirtualMachine) -> PyResult {
-        let obj = self.weak.upgrade().ok_or_else(|| {
-            vm.new_exception_msg(
-                vm.ctx.exceptions.reference_error.clone(),
-                "weakly-referenced object no longer exists".to_owned(),
-            )
-        })?;
+        let obj = self.weak.upgrade().ok_or_else(|| new_reference_error(vm))?;
         obj.get_attr(attr_name, vm)
     }
+    #[pymethod(magic)]
+    fn str(&self, vm: &VirtualMachine) -> PyResult<PyStrRef> {
+        match self.weak.upgrade() {
+            Some(obj) => obj.str(vm),
+            None => Err(new_reference_error(vm)),
+        }
+    }
+}
+
+fn new_reference_error(vm: &VirtualMachine) -> PyRef<super::PyBaseException> {
+    vm.new_exception_msg(
+        vm.ctx.exceptions.reference_error.clone(),
+        "weakly-referenced object no longer exists".to_owned(),
+    )
 }
 
 impl SetAttr for PyWeakProxy {