ABI Bytes from ABI Uint8

pyteal/ast/abi/uint.py

@@ -55,15 +55,19 @@ def __init__(
     def new_instance(self) -> "Uint8":
         return Uint8()
 
-    def set(self, value: Union[int, Expr, "Uint8"]) -> Expr:
+    def set(self, value: Union[int, Expr, "Uint8", "Byte"]) -> Expr:
         checked = False
         if type(value) is int:
             if value >= 2 ** self.bit_size:
-                raise TealInputError("Value exceeds Uint8 maximum: {}".format(value))
+                raise TealInputError(
+                    "Value exceeds {} maximum: {}".format(
+                        self.__class__.__name__, value
+                    )
+                )
             value = Int(value)
             checked = True
 
-        if type(value) is Uint8:
+        if type(value) is Uint8 or type(value) is Byte:
             value = value.get()
             checked = True
 
@@ -93,7 +97,19 @@ def encode(self) -> Expr:
 
 Uint8.__module__ = "pyteal"
 
-Byte = Uint8
+
+class Byte(Uint8):
+    def __init__(self) -> None:
+        super().__init__()
+
+    def new_instance(self) -> "Byte":
+        return Byte()
+
+    def __str__(self) -> str:
+        return "byte"
+
+
+Byte.__module__ = "pyteal"
 
 
 class Uint16(Uint):

pyteal/ast/abi/uint_test.py

@@ -81,6 +81,7 @@ def test_Uint_bits():
 def test_Uint_str():
     for test in testData:
         assert str(test.uintType) == "uint{}".format(test.expectedBits)
+    assert str(abi.Byte()) == "byte"
 
 
 def test_Uint_is_dynamic():
@@ -251,3 +252,37 @@ def test_Uint_encode():
 
         with TealComponent.Context.ignoreExprEquality():
             assert actual == expected
+
+
+def test_ByteUint8_set_error():
+    with pytest.raises(TealInputError) as uint8_err_msg:
+        abi.Uint8().set(256)
+    assert "Uint8" in uint8_err_msg.__str__()
+
+    with pytest.raises(TealInputError) as byte_err_msg:
+        abi.Byte().set(256)
+    assert "Byte" in byte_err_msg.__str__()
+
+
+def test_ByteUint8_mutual_conversion():
+    for type_a, type_b in [(abi.Uint8, abi.Byte), (abi.Byte, abi.Uint8)]:
+        type_b_instance = type_b()
+        other = type_a()
+        expr = type_b_instance.set(other)
+
+        assert expr.type_of() == TealType.none
+        assert not expr.has_return()
+
+        expected = TealSimpleBlock(
+            [
+                TealOp(None, Op.load, other.stored_value.slot),
+                TealOp(None, Op.store, type_b_instance.stored_value.slot),
+            ]
+        )
+
+        actual, _ = expr.__teal__(options)
+        actual.addIncoming()
+        actual = TealBlock.NormalizeBlocks(actual)
+
+        with TealComponent.Context.ignoreExprEquality():
+            assert actual == expected