Support disabling implicitly via 1/1 group config

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "pytest-cdist"
-version = "0.4.0"
+version = "0.5.0"
 description = "A pytest plugin to split your test suite into multiple parts"
 authors = [
   { name = "Janek Nouvertné", email = "provinzkraut@posteo.de" },

pytest_cdist/plugin.py

@@ -288,6 +288,9 @@ def pytest_collection_modifyitems(
     if cdist_config is None:
         return
 
+    if cdist_config.total_groups == 1:
+        return
+
     groups = _partition_list(items, cdist_config.total_groups)
 
     for group_steal in cdist_config.group_steal:

tests/test_plugin.py

@@ -5,6 +5,19 @@
 import pytest
 
 
+def test_disable_on_one_group(pytester: pytest.Pytester) -> None:
+    pytester.makepyfile("""
+    def test_one():
+        assert True
+
+    def test_two():
+        assert True
+    """)
+
+    result = pytester.runpytest("--cdist-group=1/1")
+    result.assert_outcomes(passed=2, deselected=0)
+
+
 def test_split_simple(pytester: pytest.Pytester) -> None:
     pytester.makepyfile("""
     def test_one():