Merge pull request #2942 from qingshi163/bytes-fromhex-subclass

fix bytes and bytearray fromhex to support subclass

Lib/test/test_bytes.py

@@ -1722,8 +1722,6 @@ class AssortedBytesTest(unittest.TestCase):
             self.assertEqual(f(b"'"), '''b"'"''') # '''
             self.assertEqual(f(b"'\""), r"""b'\'"'""") # '
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     @check_bytes_warnings
     def test_format(self):
         for b in b'abc', bytearray(b'abc'):
@@ -1962,8 +1960,6 @@ class SubclassTest:
             self.assertEqual(type(a), type(b))
             self.assertEqual(type(a.y), type(b.y))
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_fromhex(self):
         b = self.type2test.fromhex('1a2B30')
         self.assertEqual(b, b'\x1a\x2b\x30')

extra_tests/snippets/bytes.py

@@ -647,3 +647,12 @@ assert id(b) != id(b * -1)
 assert id(b) != id(b * 0)
 assert id(b) != id(b * 1)
 assert id(b) != id(b * 2)
+
+class B1(bytearray):
+    def __new__(cls, value):
+        assert type(value) == bytes
+        me = super().__new__(cls, value)
+        me.foo = 'bar'
+        return me
+b = B1.fromhex('a0a1a2')
+assert b.foo == 'bar'

vm/src/builtins/bytearray.rs

@@ -20,7 +20,9 @@ use crate::common::lock::{
 };
 use crate::function::{FuncArgs, OptionalArg, OptionalOption};
 use crate::sliceable::{PySliceableSequence, PySliceableSequenceMut, SequenceIndex};
-use crate::slots::{AsBuffer, Comparable, Hashable, Iterable, PyComparisonOp, PyIter, Unhashable};
+use crate::slots::{
+    AsBuffer, Callable, Comparable, Hashable, Iterable, PyComparisonOp, PyIter, Unhashable,
+};
 use crate::utils::Either;
 use crate::vm::VirtualMachine;
 use crate::{
@@ -373,9 +375,11 @@ impl PyByteArray {
         self.inner().hex(sep, bytes_per_sep, vm)
     }
 
-    #[pymethod]
-    fn fromhex(string: PyStrRef, vm: &VirtualMachine) -> PyResult<PyByteArray> {
-        Ok(PyBytesInner::fromhex(string.as_str(), vm)?.into())
+    #[pyclassmethod]
+    fn fromhex(cls: PyTypeRef, string: PyStrRef, vm: &VirtualMachine) -> PyResult {
+        let bytes = PyBytesInner::fromhex(string.as_str(), vm)?;
+        let bytes = vm.ctx.new_bytes(bytes);
+        Callable::call(&cls, vec![bytes].into(), vm)
     }
 
     #[pymethod]

vm/src/builtins/bytes.rs

@@ -12,7 +12,7 @@ use crate::bytesinner::{
 use crate::byteslike::ArgBytesLike;
 use crate::common::hash::PyHash;
 use crate::function::{OptionalArg, OptionalOption};
-use crate::slots::{AsBuffer, Comparable, Hashable, Iterable, PyComparisonOp, PyIter};
+use crate::slots::{AsBuffer, Callable, Comparable, Hashable, Iterable, PyComparisonOp, PyIter};
 use crate::utils::Either;
 use crate::vm::VirtualMachine;
 use crate::{
@@ -222,9 +222,11 @@ impl PyBytes {
         self.inner.hex(sep, bytes_per_sep, vm)
     }
 
-    #[pymethod]
-    fn fromhex(string: PyStrRef, vm: &VirtualMachine) -> PyResult<PyBytes> {
-        Ok(PyBytesInner::fromhex(string.as_str(), vm)?.into())
+    #[pyclassmethod]
+    fn fromhex(cls: PyTypeRef, string: PyStrRef, vm: &VirtualMachine) -> PyResult {
+        let bytes = PyBytesInner::fromhex(string.as_str(), vm)?;
+        let bytes = vm.ctx.new_bytes(bytes);
+        Callable::call(&cls, vec![bytes].into(), vm)
     }
 
     #[pymethod]

vm/src/builtins/object.rs

@@ -217,9 +217,10 @@ impl PyBaseObject {
         if format_spec.as_str().is_empty() {
             vm.to_str(&obj)
         } else {
-            Err(vm.new_type_error(
-                "unsupported format string passed to object.__format__".to_string(),
-            ))
+            Err(vm.new_type_error(format!(
+                "unsupported format string passed to {}.__format__",
+                obj.class().name
+            )))
         }
     }