add hexbytes node

vyper/ast/nodes.py

@@ -916,6 +916,25 @@ def s(self):
         return self.value
 
 
+class HexBytes(Constant):
+    __slots__ = ()
+    _translated_fields = {"s": "value"}
+
+    def __init__(self, parent: Optional["VyperNode"] = None, **kwargs: dict):
+        super().__init__(parent, **kwargs)
+        if isinstance(self.value, str):
+            self.value = bytes.fromhex(self.value)
+
+    def to_dict(self):
+        ast_dict = super().to_dict()
+        ast_dict["value"] = f"0x{self.value.hex()}"
+        return ast_dict
+
+    @property
+    def s(self):
+        return self.value
+
+
 class List(ExprNode):
     __slots__ = ("elements",)
     _translated_fields = {"elts": "elements"}

vyper/ast/parse.py

@@ -406,11 +406,7 @@ def visit_Constant(self, node):
                         node.lineno,
                         node.col_offset,
                     )
-
-                byte_val = bytes.fromhex(node.value)
-
-                node.ast_type = "Bytes"
-                node.value = byte_val
+                node.ast_type = "HexBytes"
             else:
                 node.ast_type = "Str"
         elif isinstance(node.value, bytes):

vyper/codegen/expr.py

@@ -140,6 +140,12 @@ def parse_Str(self):
 
     # Byte literals
     def parse_Bytes(self):
+        return self._parse_bytes()
+
+    def parse_HexBytes(self):
+        return self._parse_bytes()
+
+    def _parse_bytes(self, bytes):
         bytez = self.expr.value
         bytez_length = len(self.expr.value)
         typ = BytesT(bytez_length)

vyper/semantics/types/bytestrings.py

@@ -159,7 +159,7 @@ class BytesT(_BytestringT):
     typeclass = "bytes"
 
     _id = "Bytes"
-    _valid_literal = (vy_ast.Bytes,)
+    _valid_literal = (vy_ast.Bytes, vy_ast.HexBytes)
 
     @property
     def abi_type(self) -> ABIType: