Add tests for different configs in different directories

Author: Aleksey Petryankin

tests/config/test_per_directory_config.py

@@ -2,8 +2,16 @@
 # For details: https://github.com/pylint-dev/pylint/blob/main/LICENSE
 # Copyright (c) https://github.com/pylint-dev/pylint/blob/main/CONTRIBUTORS.txt
 
+from __future__ import annotations
+
+import os
+import os.path
 from pathlib import Path
 
+import pytest
+from pytest import CaptureFixture
+
+from pylint.lint import Run as LintRun
 from pylint.testutils._run import _Run as Run
 
 
@@ -21,3 +29,131 @@ def test_fall_back_on_base_config(tmp_path: Path) -> None:
         f.write("1")
     Run([str(test_file)], exit=False)
     assert id(runner.linter.config) == id(runner.linter._base_config)
+
+
+@pytest.fixture
+def _create_subconfig_test_fs(tmp_path: Path) -> tuple[Path, Path, Path]:
+    level1_dir = tmp_path / "level1_dir"
+    level1_init = level1_dir / "__init__.py"
+    conf_file1 = level1_dir / "pylintrc"
+    test_file1 = level1_dir / "a.py"
+    subdir = level1_dir / "sub"
+    level2_init = subdir / "__init__.py"
+    conf_file2 = subdir / "pylintrc"
+    test_file2 = subdir / "b.py"
+    os.makedirs(subdir)
+    level1_init.touch()
+    level2_init.touch()
+    test_file_text = "#LEVEL1\n#LEVEL2\n#ALL_LEVELS\n#TODO\n"
+    test_file1.write_text(test_file_text)
+    test_file2.write_text(test_file_text)
+    conf1 = "[MISCELLANEOUS]\nnotes=LEVEL1,ALL_LEVELS"
+    conf2 = "[MISCELLANEOUS]\nnotes=LEVEL2,ALL_LEVELS"
+    conf_file1.write_text(conf1)
+    conf_file2.write_text(conf2)
+    return level1_dir, test_file1, test_file2
+
+
+# check that use-parent-configs doesn't break anything
+@pytest.mark.parametrize(
+    "local_config_args",
+    [["--use-local-configs=y"], ["--use-local-configs=y", "--use-parent-configs=y"]],
+)
+# check files and configs from top-level package or subpackage
+@pytest.mark.parametrize("test_file_index", [0, 1])
+# check cases when cwd contains pylintrc or not
+@pytest.mark.parametrize("start_dir_modificator", [".", ".."])
+def test_subconfig_vs_root_config(
+    _create_subconfig_test_fs: tuple[Path, Path, Path],
+    capsys: CaptureFixture,
+    test_file_index: int,
+    local_config_args: list[str],
+    start_dir_modificator: str,
+) -> None:
+    """Test that each checked file or module uses config
+    from its own directory.
+    """
+    level1_dir, *tmp_files = _create_subconfig_test_fs
+    test_file = tmp_files[test_file_index]
+    start_dir = (level1_dir / start_dir_modificator).resolve()
+
+    orig_cwd = os.getcwd()
+    output = [f"{start_dir = }, {test_file = }"]
+    os.chdir(start_dir)
+    for _ in range(2):
+        # _Run adds --rcfile, which overrides config from cwd, so we need original Run here
+        LintRun([*local_config_args, str(test_file)], exit=False)
+        output.append(capsys.readouterr().out.replace("\\n", "\n"))
+
+        test_file = test_file.parent
+    os.chdir(orig_cwd)
+
+    expected_note = f"LEVEL{test_file_index+1}"
+    assert (
+        expected_note in output[1]
+    ), f"readable debug output:\n{output[0]}\n{output[1]}"
+    assert (
+        expected_note in output[2]
+    ), f"readable debug output:\n{output[0]}\n{output[2]}"
+    if test_file_index == 0:
+        # 'pylint level1_dir/' should use config from subpackage when checking level1_dir/sub/b.py
+        assert (
+            "LEVEL2" in output[2]
+        ), f"readable debug output:\n{output[0]}\n{output[2]}"
+    else:
+        # 'pylint level1_dir/sub/b.py' and 'pylint level1_dir/sub/' should use
+        # level1_dir/sub/pylintrc, not level1_dir/pylintrc
+        assert (
+            "LEVEL1" not in output[1]
+        ), f"readable debug output:\n{output[0]}\n{output[1]}"
+        assert (
+            "LEVEL1" not in output[2]
+        ), f"readable debug output:\n{output[0]}\n{output[2]}"
+
+
+@pytest.mark.parametrize("test_file_index", [0, 1])
+def test_subconfig_vs_cli_arg(
+    _create_subconfig_test_fs: tuple[Path, Path, Path],
+    capsys: CaptureFixture,
+    test_file_index: int,
+) -> None:
+    """Test that cli args have priority over subconfigs."""
+    test_root, *tmp_files = _create_subconfig_test_fs
+    test_file = tmp_files[test_file_index]
+    orig_cwd = os.getcwd()
+    os.chdir(test_root)
+    Run(["--notes=FIXME", "--use-local-configs=y", str(test_file)], exit=False)
+    output = capsys.readouterr().out.replace("\\n", "\n")
+    os.chdir(orig_cwd)
+
+    # check that cli arg overrides default value
+    assert "TODO" not in output
+    # notes=FIXME in cli should override all pylintrc configs
+    assert "ALL_LEVELS" not in output
+
+
+def _create_parent_subconfig_fs(tmp_path: Path) -> Path:
+    level1_dir = tmp_path / "package"
+    conf_file = level1_dir / "pylintrc"
+    subdir = level1_dir / "sub"
+    test_file = subdir / "b.py"
+    os.makedirs(subdir)
+    test_file_text = "#LEVEL1\n#LEVEL2\n#TODO\n"
+    test_file.write_text(test_file_text)
+    conf = "[MISCELLANEOUS]\nnotes=LEVEL1,LEVEL2"
+    conf_file.write_text(conf)
+    return test_file
+
+
+def test_subconfig_in_parent(tmp_path: Path, capsys: CaptureFixture) -> None:
+    """Test that searching local configs in parent directories works."""
+    test_file = _create_parent_subconfig_fs(tmp_path)
+    orig_cwd = os.getcwd()
+    os.chdir(tmp_path)
+    Run(["--use-parent-configs=y", "--use-local-configs=y", str(test_file)], exit=False)
+    output1 = capsys.readouterr().out.replace("\\n", "\n")
+    os.chdir(orig_cwd)
+
+    # check that file is linted with config from ../, which is not a cwd
+    assert "TODO" not in output1
+    assert "LEVEL1" in output1