ensure step is int (#766)

* ensure step is `int`

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* some more tests

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

tests/test_step.py

@@ -9,6 +9,7 @@ def test_step(server, s22):
     vis.extend(s22)
 
     assert vis.step == 0
+    assert isinstance(vis.step, int)
 
     assert len(vis) == 22
 
@@ -23,3 +24,4 @@ def test_step(server, s22):
 
     vis.step = 5
     assert vis.step == 5
+    assert isinstance(vis.step, int)

zndraw/zndraw.py

@@ -419,9 +419,11 @@ def selection(self, value: list[int]):
     @property
     def step(self) -> int:
         try:
-            return znsocket.Dict(
-                self.r, f"room:{self.token}:step", socket=self._refresh_client
-            )["grp-0"]
+            return int(
+                znsocket.Dict(
+                    self.r, f"room:{self.token}:step", socket=self._refresh_client
+                )["grp-0"]
+            )
         except KeyError:
             return 0