feat: add support for tuples to the marshaller (#267)

src/dbus_fast/_private/marshaller.pxd

@@ -72,7 +72,7 @@ cdef class Marshaller:
         written=cython.uint,
         i=cython.uint,
     )
-    cdef unsigned int _write_struct(self, cython.list array, SignatureType type_)
+    cdef unsigned int _write_struct(self, object array, SignatureType type_)
 
     cpdef write_variant(self, Variant variant, SignatureType type_)
 

src/dbus_fast/_private/marshaller.py

@@ -136,10 +136,14 @@ class Marshaller:
 
         return written + array_len
 
-    def write_struct(self, array: List[Any], type_: SignatureType) -> int:
+    def write_struct(
+        self, array: Union[Tuple[Any], List[Any]], type_: SignatureType
+    ) -> int:
         return self._write_struct(array, type_)
 
-    def _write_struct(self, array: List[Any], type_: SignatureType) -> int:
+    def _write_struct(
+        self, array: Union[Tuple[Any], List[Any]], type_: SignatureType
+    ) -> int:
         written = self._align(8)
         for i, value in enumerate(array):
             written += self._write_single(type_.children[i], value)

src/dbus_fast/service.py

@@ -516,9 +516,10 @@ class ServiceInterface:
             if out_len == 1:
                 result = [result]
             else:
-                if type(result) is not list:
+                result_type = type(result)
+                if result_type is not list and result_type is not tuple:
                     raise SignatureBodyMismatchError(
-                        "Expected signal to return a list of arguments"
+                        "Expected signal to return a list or tuple of arguments"
                     )
 
         if out_len != len(result):

src/dbus_fast/signature.py

@@ -258,10 +258,9 @@ class SignatureType:
                 child_type.verify(member)
 
     def _verify_struct(self, body: Any) -> None:
-        # TODO allow tuples
-        if not isinstance(body, list):
+        if not isinstance(body, (list, tuple)):
             raise SignatureBodyMismatchError(
-                f'DBus STRUCT type "(" must be Python type "list", got {type(body)}'
+                f'DBus STRUCT type "(" must be Python type "list" or "tuple", got {type(body)}'
             )
 
         if len(body) != len(self.children):

tests/test_marshaller.py

@@ -714,3 +714,29 @@ def test_unmarshall_multi_byte_string():
     assert unmarshaller.message.signature == "as"
     unpacked = unpack_variants(message.body)
     assert unpacked == [["//doesntmatter/über"]]
+
+
+def test_marshalling_struct_accepts_tuples():
+    """Test marshalling a struct accepts tuples."""
+    msg = Message(
+        path="/test",
+        member="test",
+        signature="(s)",
+        body=[(RaucState.GOOD,)],
+    )
+    marshalled = msg._marshall(False)
+    unmarshalled_msg = Unmarshaller(io.BytesIO(marshalled)).unmarshall()
+    assert unpack_variants(unmarshalled_msg.body)[0] == [RaucState.GOOD.value]
+
+
+def test_marshalling_struct_accepts_lists():
+    """Test marshalling a struct accepts lists."""
+    msg = Message(
+        path="/test",
+        member="test",
+        signature="(s)",
+        body=[[RaucState.GOOD]],
+    )
+    marshalled = msg._marshall(False)
+    unmarshalled_msg = Unmarshaller(io.BytesIO(marshalled)).unmarshall()
+    assert unpack_variants(unmarshalled_msg.body)[0] == [RaucState.GOOD.value]

tests/test_signature.py

@@ -231,3 +231,9 @@ def test_variant_signature_type():
 
     with pytest.raises(SignatureBodyMismatchError):
         Variant(tree.types[0], "wrong")
+
+
+def test_struct_accepts_tuples_or_lists():
+    tree = SignatureTree("(s)")
+    tree.verify([("ok",)])
+    tree.verify([["ok"]])