chore: Allow merge to still be used from the command line.

Author: spencer-tb

src/pytest_plugins/forks/forks.py

@@ -176,9 +176,14 @@ def pytest_configure(config):
     for d in fork_covariant_descriptors:
         config.addinivalue_line("markers", f"{d.marker_name}: {d.description}")
 
-    single_fork = config.getoption("single_fork")
-    forks_from = config.getoption("forks_from")
-    forks_until = config.getoption("forks_until")
+    def get_fork_option(config, option_name):
+        """Post-process get option to allow for external fork conditions."""
+        option = config.getoption(option_name)
+        return "Paris" if option == "Merge" else option
+
+    single_fork = get_fork_option(config, "single_fork")
+    forks_from = get_fork_option(config, "forks_from")
+    forks_until = get_fork_option(config, "forks_until")
     show_fork_help = config.getoption("show_fork_help")
 
     all_forks = get_forks()

src/pytest_plugins/forks/tests/test_forks.py

@@ -131,3 +131,34 @@ def test_all_forks({StateTest.pytest_parameter_name()}):
         skipped=0,
         errors=0,
     )
+
+
+def test_from_merge_until_merge_option_no_validity_marker(pytester, fork_map):
+    """
+    Test test parametrization with:
+    - --from Merge command-line option,
+    - --until Merge command-line option,
+    - no fork validity marker.
+    """
+    pytester.makepyfile(
+        f"""
+        import pytest
+
+        def test_all_forks({StateTest.pytest_parameter_name()}):
+            pass
+        """
+    )
+    pytester.copy_example(name="pytest.ini")
+    result = pytester.runpytest("-v", "--from", "Merge", "--until", "Merge")
+    forks_under_test = forks_from_until(fork_map["Paris"], fork_map["Paris"])
+    expected_passed = len(forks_under_test) * len(StateTest.fixture_formats())
+    stdout = "\n".join(result.stdout.lines)
+    for fork in forks_under_test:
+        for fixture_format in StateTest.fixture_formats():
+            assert f":test_all_forks[fork_{fork}-{fixture_format.name.lower()}]" in stdout
+    result.assert_outcomes(
+        passed=expected_passed,
+        failed=0,
+        skipped=0,
+        errors=0,
+    )