tests: update project.toml to use parallel flag correctly

Author: harryswift01

pyproject.toml

@@ -85,16 +85,13 @@ docs = [
 CodeEntropy = "CodeEntropy.cli:main"
 
 [tool.pytest.ini_options]
-addopts = "-n auto -ra -vv --dist=loadscope"
+testpaths = ["tests"]
 
-markers = [
-    "regression: end-to-end regression tests against baselines",
-    "slow: long-running regression tests (20-30+ minutes)"
-]
+addopts = "-n auto -vv -ra"
 
-testpaths = [
-    "tests/unit",
-    "tests/regression"
+markers = [
+  "regression: end-to-end regression tests against baselines",
+  "slow: long-running regression tests (20-30+ minutes)",
 ]
 
 [tool.ruff]

tests/__init__.py

@@ -1,4 +1 @@
-"""
-Empty init file in case you choose a package besides PyTest such as Nose which may look
-for such a file.
-"""
+""" """

tests/regression/test_regression.py

@@ -10,6 +10,27 @@
 from tests.regression.cases import discover_cases
 from tests.regression.helpers import run_codeentropy_with_config
 
+CASES = discover_cases()
+
+
+def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
+    """
+    Dynamically parametrize regression test cases.
+
+    This hook enables pytest-xdist to distribute individual regression cases
+    across multiple workers by generating test parametrization at collection time.
+
+    Args:
+        metafunc (pytest.Metafunc): Pytest metafunction object used to inspect
+            and modify test function parametrization.
+    """
+    if "case" in metafunc.fixturenames:
+        metafunc.parametrize(
+            "case",
+            CASES,
+            ids=[c.id for c in CASES],
+        )
+
 
 def _group_index(payload: dict[str, Any]) -> dict[str, dict[str, Any]]:
     """
@@ -106,9 +127,10 @@ def _compare_grouped(
 
 
 @pytest.mark.regression
-@pytest.mark.parametrize("case", discover_cases())
 def test_regression_matches_baseline(
-    tmp_path: Path, case, request: pytest.FixtureRequest
+    tmp_path: Path,
+    case,
+    request: pytest.FixtureRequest,
 ) -> None:
     """
     Execute a regression test for a single scenario and compare against baseline.
@@ -121,8 +143,9 @@ def test_regression_matches_baseline(
 
     Args:
         tmp_path (Path): Temporary directory provided by pytest.
-        case (RegressionCase): Parameterized regression case.
-        request (pytest.FixtureRequest): Pytest request object for accessing CLI options
+        case: A RegressionCase instance containing system, config, and baseline paths.
+        request (pytest.FixtureRequest): Pytest request object used to access CLI
+        options.
 
     Raises:
         AssertionError: If the output does not match the baseline or baseline is missing