Avoid unknown marker warnings in tests

CHANGELOG.md

@@ -1,10 +1,13 @@
 # pytest-order Release Notes
 
+## Infrastructure
+- avoid unknown marker warning in tests (see [#101](https://github.com/pytest-dev/pytest-order/issues/101))
+
 ## [Version 1.2.0](https://pypi.org/project/pytest-order/1.2.0/) (2023-11-18)
 Allows using custom markers for ordering.
 
 ### New features
-* added option `--order-marker-prefix` to allow using custom markers for ordering
+- added option `--order-marker-prefix` to allow using custom markers for ordering
 
 ### Infrastructure
 - added pre-commit hook for linters

README.md

@@ -49,7 +49,7 @@ Features
 - sparse ordering of tests via the
   [sparse-ordering](https://pytest-order.readthedocs.io/en/stable/configuration.html#sparse-ordering) option
 - usage of custom markers for ordering using the
-  [sparse-ordering](https://pytest-order.readthedocs.io/en/stable/configuration.html#order-marker-prefix) option
+  [order-marker-prefix](https://pytest-order.readthedocs.io/en/stable/configuration.html#order-marker-prefix) option
 
 Overview
 --------

tests/test_marker_prefix.py

@@ -22,14 +22,35 @@ def test_c():
     )
 
 
+@pytest.fixture(scope="module")
+def conftest_file():
+    yield (
+        """
+        def pytest_configure(config):
+            config.addinivalue_line("markers", "my1: used in marker prefix test")
+            config.addinivalue_line("markers", "my2: used in marker prefix test")
+            config.addinivalue_line("markers", "my3: used in marker prefix test")
+        """
+    )
+
+
 @pytest.fixture
-def marker_test(test_path, marker_test_file):
+def marker_test(test_path, marker_test_file, conftest_file):
+    test_path.makepyfile(conftest=conftest_file)
     test_path.makepyfile(test_marker=marker_test_file)
     yield test_path
 
 
-def test_no_ordering(marker_test_file, item_names_for):
-    assert item_names_for(marker_test_file) == ["test_a", "test_b", "test_c"]
+def test_no_ordering(marker_test):
+    result = marker_test.runpytest("-v")
+    result.assert_outcomes(passed=3, skipped=0)
+    result.stdout.fnmatch_lines(
+        [
+            "test_marker.py::test_a PASSED",
+            "test_marker.py::test_b PASSED",
+            "test_marker.py::test_c PASSED",
+        ]
+    )
 
 
 def test_order_with_marker_prefix(marker_test):
@@ -110,7 +131,8 @@ def test_c():
     )
 
 
-def test_mix_marker_prefix_with_order_marks(test_path):
+def test_mix_marker_prefix_with_order_marks(test_path, conftest_file):
+    test_path.makepyfile(conftest=conftest_file)
     test_path.makepyfile(
         test_marker=(
             """