config/findpaths: convert from py.path.local to pathlib

4 files changed, 227 insertions, 176 deletions

diff --git a/src/_pytest/config/__init__.py b/src/_pytest/config/__init__.py
index 455a14b40..6305cdbd5 100644
--- a/src/_pytest/config/__init__.py
+++ b/src/_pytest/config/__init__.py
@@ -1006,12 +1006,15 @@ class Config:
         ns, unknown_args = self._parser.parse_known_and_unknown_args(
             args, namespace=copy.copy(self.option)
         )
-        self.rootdir, self.inifile, self.inicfg = determine_setup(
+        rootpath, inipath, inicfg = determine_setup(
             ns.inifilename,
             ns.file_or_dir + unknown_args,
             rootdir_cmd_arg=ns.rootdir or None,
             config=self,
         )
+        self.rootdir = py.path.local(str(rootpath))
+        self.inifile = py.path.local(str(inipath)) if inipath else None
+        self.inicfg = inicfg
         self._parser.extra_info["rootdir"] = self.rootdir
         self._parser.extra_info["inifile"] = self.inifile
         self._parser.addini("addopts", "extra command line options", "args")
diff --git a/src/_pytest/config/findpaths.py b/src/_pytest/config/findpaths.py
index be25fc829..65120e484 100644
--- a/src/_pytest/config/findpaths.py
+++ b/src/_pytest/config/findpaths.py
@@ -1,23 +1,28 @@
+import itertools
 import os
+import sys
 from typing import Dict
 from typing import Iterable
 from typing import List
 from typing import Optional
+from typing import Sequence
 from typing import Tuple
 from typing import Union
 
 import iniconfig
-import py
 
 from .exceptions import UsageError
 from _pytest.compat import TYPE_CHECKING
 from _pytest.outcomes import fail
+from _pytest.pathlib import absolutepath
+from _pytest.pathlib import commonpath
+from _pytest.pathlib import Path
 
 if TYPE_CHECKING:
     from . import Config
 
 
-def _parse_ini_config(path: py.path.local) -> iniconfig.IniConfig:
+def _parse_ini_config(path: Path) -> iniconfig.IniConfig:
     """Parse the given generic '.ini' file using legacy IniConfig parser, returning
     the parsed object.
 
@@ -30,7 +35,7 @@ def _parse_ini_config(path: py.path.local) -> iniconfig.IniConfig:
 
 
 def load_config_dict_from_file(
-    filepath: py.path.local,
+    filepath: Path,
 ) -> Optional[Dict[str, Union[str, List[str]]]]:
     """Load pytest configuration from the given file path, if supported.
 
@@ -38,18 +43,18 @@ def load_config_dict_from_file(
     """
 
     # Configuration from ini files are obtained from the [pytest] section, if present.
-    if filepath.ext == ".ini":
+    if filepath.suffix == ".ini":
         iniconfig = _parse_ini_config(filepath)
 
         if "pytest" in iniconfig:
             return dict(iniconfig["pytest"].items())
         else:
             # "pytest.ini" files are always the source of configuration, even if empty.
-            if filepath.basename == "pytest.ini":
+            if filepath.name == "pytest.ini":
                 return {}
 
     # '.cfg' files are considered if they contain a "[tool:pytest]" section.
-    elif filepath.ext == ".cfg":
+    elif filepath.suffix == ".cfg":
         iniconfig = _parse_ini_config(filepath)
 
         if "tool:pytest" in iniconfig.sections:
@@ -60,7 +65,7 @@ def load_config_dict_from_file(
             fail(CFG_PYTEST_SECTION.format(filename="setup.cfg"), pytrace=False)
 
     # '.toml' files are considered if they contain a [tool.pytest.ini_options] table.
-    elif filepath.ext == ".toml":
+    elif filepath.suffix == ".toml":
         import toml
 
         config = toml.load(str(filepath))
@@ -79,9 +84,9 @@ def load_config_dict_from_file(
 
 
 def locate_config(
-    args: Iterable[Union[str, py.path.local]]
+    args: Iterable[Path],
 ) -> Tuple[
-    Optional[py.path.local], Optional[py.path.local], Dict[str, Union[str, List[str]]],
+    Optional[Path], Optional[Path], Dict[str, Union[str, List[str]]],
 ]:
     """Search in the list of arguments for a valid ini-file for pytest,
     and return a tuple of (rootdir, inifile, cfg-dict)."""
@@ -93,62 +98,77 @@ def locate_config(
     ]
     args = [x for x in args if not str(x).startswith("-")]
     if not args:
-        args = [py.path.local()]
+        args = [Path.cwd()]
     for arg in args:
-        arg = py.path.local(arg)
-        for base in arg.parts(reverse=True):
+        argpath = absolutepath(arg)
+        for base in itertools.chain((argpath,), reversed(argpath.parents)):
             for config_name in config_names:
-                p = base.join(config_name)
-                if p.isfile():
+                p = base / config_name
+                if p.is_file():
                     ini_config = load_config_dict_from_file(p)
                     if ini_config is not None:
                         return base, p, ini_config
     return None, None, {}
 
 
-def get_common_ancestor(paths: Iterable[py.path.local]) -> py.path.local:
-    common_ancestor = None  # type: Optional[py.path.local]
+def get_common_ancestor(paths: Iterable[Path]) -> Path:
+    common_ancestor = None  # type: Optional[Path]
     for path in paths:
         if not path.exists():
             continue
         if common_ancestor is None:
             common_ancestor = path
         else:
-            if path.relto(common_ancestor) or path == common_ancestor:
+            if common_ancestor in path.parents or path == common_ancestor:
                 continue
-            elif common_ancestor.relto(path):
+            elif path in common_ancestor.parents:
                 common_ancestor = path
             else:
-                shared = path.common(common_ancestor)
+                shared = commonpath(path, common_ancestor)
                 if shared is not None:
                     common_ancestor = shared
     if common_ancestor is None:
-        common_ancestor = py.path.local()
-    elif common_ancestor.isfile():
-        common_ancestor = common_ancestor.dirpath()
+        common_ancestor = Path.cwd()
+    elif common_ancestor.is_file():
+        common_ancestor = common_ancestor.parent
     return common_ancestor
 
 
-def get_dirs_from_args(args: Iterable[str]) -> List[py.path.local]:
+def get_dirs_from_args(args: Iterable[str]) -> List[Path]:
     def is_option(x: str) -> bool:
         return x.startswith("-")
 
     def get_file_part_from_node_id(x: str) -> str:
         return x.split("::")[0]
 
-    def get_dir_from_path(path: py.path.local) -> py.path.local:
-        if path.isdir():
+    def get_dir_from_path(path: Path) -> Path:
+        if path.is_dir():
             return path
-        return py.path.local(path.dirname)
+        return path.parent
+
+    if sys.version_info < (3, 8):
+
+        def safe_exists(path: Path) -> bool:
+            # On Python<3.8, this can throw on paths that contain characters
+            # unrepresentable at the OS level.
+            try:
+                return path.exists()
+            except OSError:
+                return False
+
+    else:
+
+        def safe_exists(path: Path) -> bool:
+            return path.exists()
 
     # These look like paths but may not exist
     possible_paths = (
-        py.path.local(get_file_part_from_node_id(arg))
+        absolutepath(get_file_part_from_node_id(arg))
         for arg in args
         if not is_option(arg)
     )
 
-    return [get_dir_from_path(path) for path in possible_paths if path.exists()]
+    return [get_dir_from_path(path) for path in possible_paths if safe_exists(path)]
 
 
 CFG_PYTEST_SECTION = "[pytest] section in {filename} files is no longer supported, change to [tool:pytest] instead."
@@ -156,15 +176,15 @@ CFG_PYTEST_SECTION = "[pytest] section in {filename} files is no longer supporte
 
 def determine_setup(
     inifile: Optional[str],
-    args: List[str],
+    args: Sequence[str],
     rootdir_cmd_arg: Optional[str] = None,
     config: Optional["Config"] = None,
-) -> Tuple[py.path.local, Optional[py.path.local], Dict[str, Union[str, List[str]]]]:
+) -> Tuple[Path, Optional[Path], Dict[str, Union[str, List[str]]]]:
     rootdir = None
     dirs = get_dirs_from_args(args)
     if inifile:
-        inipath_ = py.path.local(inifile)
-        inipath = inipath_  # type: Optional[py.path.local]
+        inipath_ = absolutepath(inifile)
+        inipath = inipath_  # type: Optional[Path]
         inicfg = load_config_dict_from_file(inipath_) or {}
         if rootdir_cmd_arg is None:
             rootdir = get_common_ancestor(dirs)
@@ -172,8 +192,10 @@ def determine_setup(
         ancestor = get_common_ancestor(dirs)
         rootdir, inipath, inicfg = locate_config([ancestor])
         if rootdir is None and rootdir_cmd_arg is None:
-            for possible_rootdir in ancestor.parts(reverse=True):
-                if possible_rootdir.join("setup.py").exists():
+            for possible_rootdir in itertools.chain(
+                (ancestor,), reversed(ancestor.parents)
+            ):
+                if (possible_rootdir / "setup.py").is_file():
                     rootdir = possible_rootdir
                     break
             else:
@@ -181,16 +203,16 @@ def determine_setup(
                     rootdir, inipath, inicfg = locate_config(dirs)
                 if rootdir is None:
                     if config is not None:
-                        cwd = config.invocation_dir
+                        cwd = config.invocation_params.dir
                     else:
-                        cwd = py.path.local()
+                        cwd = Path.cwd()
                     rootdir = get_common_ancestor([cwd, ancestor])
                     is_fs_root = os.path.splitdrive(str(rootdir))[1] == "/"
                     if is_fs_root:
                         rootdir = ancestor
     if rootdir_cmd_arg:
-        rootdir = py.path.local(os.path.expandvars(rootdir_cmd_arg))
-        if not rootdir.isdir():
+        rootdir = absolutepath(os.path.expandvars(rootdir_cmd_arg))
+        if not rootdir.is_dir():
             raise UsageError(
                 "Directory '{}' not found. Check your '--rootdir' option.".format(
                     rootdir
diff --git a/testing/test_config.py b/testing/test_config.py
index 26d2a3ef0..346edb330 100644
--- a/testing/test_config.py
+++ b/testing/test_config.py
@@ -21,17 +21,27 @@ from _pytest.config.exceptions import UsageError
 from _pytest.config.findpaths import determine_setup
 from _pytest.config.findpaths import get_common_ancestor
 from _pytest.config.findpaths import locate_config
+from _pytest.monkeypatch import MonkeyPatch
 from _pytest.pathlib import Path
+from _pytest.pytester import Testdir
 
 
 class TestParseIni:
     @pytest.mark.parametrize(
         "section, filename", [("pytest", "pytest.ini"), ("tool:pytest", "setup.cfg")]
     )
-    def test_getcfg_and_config(self, testdir, tmpdir, section, filename):
-        sub = tmpdir.mkdir("sub")
-        sub.chdir()
-        tmpdir.join(filename).write(
+    def test_getcfg_and_config(
+        self,
+        testdir: Testdir,
+        tmp_path: Path,
+        section: str,
+        filename: str,
+        monkeypatch: MonkeyPatch,
+    ) -> None:
+        sub = tmp_path / "sub"
+        sub.mkdir()
+        monkeypatch.chdir(sub)
+        (tmp_path / filename).write_text(
             textwrap.dedent(
                 """\
                 [{section}]
@@ -39,17 +49,14 @@ class TestParseIni:
                 """.format(
                     section=section
                 )
-            )
+            ),
+            encoding="utf-8",
         )
         _, _, cfg = locate_config([sub])
         assert cfg["name"] == "value"
-        config = testdir.parseconfigure(sub)
+        config = testdir.parseconfigure(str(sub))
         assert config.inicfg["name"] == "value"
 
-    def test_getcfg_empty_path(self):
-        """Correctly handle zero length arguments (a la pytest '')."""
-        locate_config([""])
-
     def test_setupcfg_uses_toolpytest_with_pytest(self, testdir):
         p1 = testdir.makepyfile("def test(): pass")
         testdir.makefile(
@@ -1168,16 +1175,17 @@ def test_collect_pytest_prefix_bug(pytestconfig):
 
 
 class TestRootdir:
-    def test_simple_noini(self, tmpdir):
-        assert get_common_ancestor([tmpdir]) == tmpdir
-        a = tmpdir.mkdir("a")
-        assert get_common_ancestor([a, tmpdir]) == tmpdir
-        assert get_common_ancestor([tmpdir, a]) == tmpdir
-        with tmpdir.as_cwd():
-            assert get_common_ancestor([]) == tmpdir
-            no_path = tmpdir.join("does-not-exist")
-            assert get_common_ancestor([no_path]) == tmpdir
-            assert get_common_ancestor([no_path.join("a")]) == tmpdir
+    def test_simple_noini(self, tmp_path: Path, monkeypatch: MonkeyPatch) -> None:
+        assert get_common_ancestor([tmp_path]) == tmp_path
+        a = tmp_path / "a"
+        a.mkdir()
+        assert get_common_ancestor([a, tmp_path]) == tmp_path
+        assert get_common_ancestor([tmp_path, a]) == tmp_path
+        monkeypatch.chdir(tmp_path)
+        assert get_common_ancestor([]) == tmp_path
+        no_path = tmp_path / "does-not-exist"
+        assert get_common_ancestor([no_path]) == tmp_path
+        assert get_common_ancestor([no_path / "a"]) == tmp_path
 
     @pytest.mark.parametrize(
         "name, contents",
@@ -1190,44 +1198,49 @@ class TestRootdir:
             pytest.param("setup.cfg", "[tool:pytest]\nx=10", id="setup.cfg"),
         ],
     )
-    def test_with_ini(self, tmpdir: py.path.local, name: str, contents: str) -> None:
-        inifile = tmpdir.join(name)
-        inifile.write(contents)
-
-        a = tmpdir.mkdir("a")
-        b = a.mkdir("b")
-        for args in ([str(tmpdir)], [str(a)], [str(b)]):
-            rootdir, parsed_inifile, _ = determine_setup(None, args)
-            assert rootdir == tmpdir
-            assert parsed_inifile == inifile
-        rootdir, parsed_inifile, ini_config = determine_setup(None, [str(b), str(a)])
-        assert rootdir == tmpdir
-        assert parsed_inifile == inifile
+    def test_with_ini(self, tmp_path: Path, name: str, contents: str) -> None:
+        inipath = tmp_path / name
+        inipath.write_text(contents, "utf-8")
+
+        a = tmp_path / "a"
+        a.mkdir()
+        b = a / "b"
+        b.mkdir()
+        for args in ([str(tmp_path)], [str(a)], [str(b)]):
+            rootpath, parsed_inipath, _ = determine_setup(None, args)
+            assert rootpath == tmp_path
+            assert parsed_inipath == inipath
+        rootpath, parsed_inipath, ini_config = determine_setup(None, [str(b), str(a)])
+        assert rootpath == tmp_path
+        assert parsed_inipath == inipath
         assert ini_config == {"x": "10"}
 
-    @pytest.mark.parametrize("name", "setup.cfg tox.ini".split())
-    def test_pytestini_overrides_empty_other(self, tmpdir: py.path.local, name) -> None:
-        inifile = tmpdir.ensure("pytest.ini")
-        a = tmpdir.mkdir("a")
-        a.ensure(name)
-        rootdir, parsed_inifile, _ = determine_setup(None, [str(a)])
-        assert rootdir == tmpdir
-        assert parsed_inifile == inifile
-
-    def test_setuppy_fallback(self, tmpdir: py.path.local) -> None:
-        a = tmpdir.mkdir("a")
-        a.ensure("setup.cfg")
-        tmpdir.ensure("setup.py")
-        rootdir, inifile, inicfg = determine_setup(None, [str(a)])
-        assert rootdir == tmpdir
-        assert inifile is None
+    @pytest.mark.parametrize("name", ["setup.cfg", "tox.ini"])
+    def test_pytestini_overrides_empty_other(self, tmp_path: Path, name: str) -> None:
+        inipath = tmp_path / "pytest.ini"
+        inipath.touch()
+        a = tmp_path / "a"
+        a.mkdir()
+        (a / name).touch()
+        rootpath, parsed_inipath, _ = determine_setup(None, [str(a)])
+        assert rootpath == tmp_path
+        assert parsed_inipath == inipath
+
+    def test_setuppy_fallback(self, tmp_path: Path) -> None:
+        a = tmp_path / "a"
+        a.mkdir()
+        (a / "setup.cfg").touch()
+        (tmp_path / "setup.py").touch()
+        rootpath, inipath, inicfg = determine_setup(None, [str(a)])
+        assert rootpath == tmp_path
+        assert inipath is None
         assert inicfg == {}
 
-    def test_nothing(self, tmpdir: py.path.local, monkeypatch) -> None:
-        monkeypatch.chdir(str(tmpdir))
-        rootdir, inifile, inicfg = determine_setup(None, [str(tmpdir)])
-        assert rootdir == tmpdir
-        assert inifile is None
+    def test_nothing(self, tmp_path: Path, monkeypatch: MonkeyPatch) -> None:
+        monkeypatch.chdir(tmp_path)
+        rootpath, inipath, inicfg = determine_setup(None, [str(tmp_path)])
+        assert rootpath == tmp_path
+        assert inipath is None
         assert inicfg == {}
 
     @pytest.mark.parametrize(
@@ -1242,45 +1255,58 @@ class TestRootdir:
         ],
     )
     def test_with_specific_inifile(
-        self, tmpdir: py.path.local, name: str, contents: str
+        self, tmp_path: Path, name: str, contents: str
     ) -> None:
-        p = tmpdir.ensure(name)
-        p.write(contents)
-        rootdir, inifile, ini_config = determine_setup(str(p), [str(tmpdir)])
-        assert rootdir == tmpdir
-        assert inifile == p
+        p = tmp_path / name
+        p.touch()
+        p.write_text(contents, "utf-8")
+        rootpath, inipath, ini_config = determine_setup(str(p), [str(tmp_path)])
+        assert rootpath == tmp_path
+        assert inipath == p
         assert ini_config == {"x": "10"}
 
-    def test_with_arg_outside_cwd_without_inifile(self, tmpdir, monkeypatch) -> None:
-        monkeypatch.chdir(str(tmpdir))
-        a = tmpdir.mkdir("a")
-        b = tmpdir.mkdir("b")
-        rootdir, inifile, _ = determine_setup(None, [str(a), str(b)])
-        assert rootdir == tmpdir
+    def test_with_arg_outside_cwd_without_inifile(
+        self, tmp_path: Path, monkeypatch: MonkeyPatch
+    ) -> None:
+        monkeypatch.chdir(tmp_path)
+        a = tmp_path / "a"
+        a.mkdir()
+        b = tmp_path / "b"
+        b.mkdir()
+        rootpath, inifile, _ = determine_setup(None, [str(a), str(b)])
+        assert rootpath == tmp_path
         assert inifile is None
 
-    def test_with_arg_outside_cwd_with_inifile(self, tmpdir) -> None:
-        a = tmpdir.mkdir("a")
-        b = tmpdir.mkdir("b")
-        inifile = a.ensure("pytest.ini")
-        rootdir, parsed_inifile, _ = determine_setup(None, [str(a), str(b)])
-        assert rootdir == a
-        assert inifile == parsed_inifile
+    def test_with_arg_outside_cwd_with_inifile(self, tmp_path: Path) -> None:
+        a = tmp_path / "a"
+        a.mkdir()
+        b = tmp_path / "b"
+        b.mkdir()
+        inipath = a / "pytest.ini"
+        inipath.touch()
+        rootpath, parsed_inipath, _ = determine_setup(None, [str(a), str(b)])
+        assert rootpath == a
+        assert inipath == parsed_inipath
 
     @pytest.mark.parametrize("dirs", ([], ["does-not-exist"], ["a/does-not-exist"]))
-    def test_with_non_dir_arg(self, dirs, tmpdir) -> None:
-        with tmpdir.ensure(dir=True).as_cwd():
-            rootdir, inifile, _ = determine_setup(None, dirs)
-            assert rootdir == tmpdir
-            assert inifile is None
-
-    def test_with_existing_file_in_subdir(self, tmpdir) -> None:
-        a = tmpdir.mkdir("a")
-        a.ensure("exist")
-        with tmpdir.as_cwd():
-            rootdir, inifile, _ = determine_setup(None, ["a/exist"])
-            assert rootdir == tmpdir
-            assert inifile is None
+    def test_with_non_dir_arg(
+        self, dirs: Sequence[str], tmp_path: Path, monkeypatch: MonkeyPatch
+    ) -> None:
+        monkeypatch.chdir(tmp_path)
+        rootpath, inipath, _ = determine_setup(None, dirs)
+        assert rootpath == tmp_path
+        assert inipath is None
+
+    def test_with_existing_file_in_subdir(
+        self, tmp_path: Path, monkeypatch: MonkeyPatch
+    ) -> None:
+        a = tmp_path / "a"
+        a.mkdir()
+        (a / "exists").touch()
+        monkeypatch.chdir(tmp_path)
+        rootpath, inipath, _ = determine_setup(None, ["a/exist"])
+        assert rootpath == tmp_path
+        assert inipath is None
 
 
 class TestOverrideIniArgs:
diff --git a/testing/test_findpaths.py b/testing/test_findpaths.py
index 3de2ea218..acb982b4c 100644
--- a/testing/test_findpaths.py
+++ b/testing/test_findpaths.py
@@ -1,74 +1,74 @@
 from textwrap import dedent
 
-import py
-
 import pytest
 from _pytest.config.findpaths import get_common_ancestor
 from _pytest.config.findpaths import load_config_dict_from_file
+from _pytest.pathlib import Path
 
 
 class TestLoadConfigDictFromFile:
-    def test_empty_pytest_ini(self, tmpdir):
+    def test_empty_pytest_ini(self, tmp_path: Path) -> None:
         """pytest.ini files are always considered for configuration, even if empty"""
-        fn = tmpdir.join("pytest.ini")
-        fn.write("")
+        fn = tmp_path / "pytest.ini"
+        fn.write_text("", encoding="utf-8")
         assert load_config_dict_from_file(fn) == {}
 
-    def test_pytest_ini(self, tmpdir):
+    def test_pytest_ini(self, tmp_path: Path) -> None:
         """[pytest] section in pytest.ini files is read correctly"""
-        fn = tmpdir.join("pytest.ini")
-        fn.write("[pytest]\nx=1")
+        fn = tmp_path / "pytest.ini"
+        fn.write_text("[pytest]\nx=1", encoding="utf-8")
         assert load_config_dict_from_file(fn) == {"x": "1"}
 
-    def test_custom_ini(self, tmpdir):
+    def test_custom_ini(self, tmp_path: Path) -> None:
         """[pytest] section in any .ini file is read correctly"""
-        fn = tmpdir.join("custom.ini")
-        fn.write("[pytest]\nx=1")
+        fn = tmp_path / "custom.ini"
+        fn.write_text("[pytest]\nx=1", encoding="utf-8")
         assert load_config_dict_from_file(fn) == {"x": "1"}
 
-    def test_custom_ini_without_section(self, tmpdir):
+    def test_custom_ini_without_section(self, tmp_path: Path) -> None:
         """Custom .ini files without [pytest] section are not considered for configuration"""
-        fn = tmpdir.join("custom.ini")
-        fn.write("[custom]")
+        fn = tmp_path / "custom.ini"
+        fn.write_text("[custom]", encoding="utf-8")
         assert load_config_dict_from_file(fn) is None
 
-    def test_custom_cfg_file(self, tmpdir):
+    def test_custom_cfg_file(self, tmp_path: Path) -> None:
         """Custom .cfg files without [tool:pytest] section are not considered for configuration"""
-        fn = tmpdir.join("custom.cfg")
-        fn.write("[custom]")
+        fn = tmp_path / "custom.cfg"
+        fn.write_text("[custom]", encoding="utf-8")
         assert load_config_dict_from_file(fn) is None
 
-    def test_valid_cfg_file(self, tmpdir):
+    def test_valid_cfg_file(self, tmp_path: Path) -> None:
         """Custom .cfg files with [tool:pytest] section are read correctly"""
-        fn = tmpdir.join("custom.cfg")
-        fn.write("[tool:pytest]\nx=1")
+        fn = tmp_path / "custom.cfg"
+        fn.write_text("[tool:pytest]\nx=1", encoding="utf-8")
         assert load_config_dict_from_file(fn) == {"x": "1"}
 
-    def test_unsupported_pytest_section_in_cfg_file(self, tmpdir):
+    def test_unsupported_pytest_section_in_cfg_file(self, tmp_path: Path) -> None:
         """.cfg files with [pytest] section are no longer supported and should fail to alert users"""
-        fn = tmpdir.join("custom.cfg")
-        fn.write("[pytest]")
+        fn = tmp_path / "custom.cfg"
+        fn.write_text("[pytest]", encoding="utf-8")
         with pytest.raises(pytest.fail.Exception):
             load_config_dict_from_file(fn)
 
-    def test_invalid_toml_file(self, tmpdir):
+    def test_invalid_toml_file(self, tmp_path: Path) -> None:
         """.toml files without [tool.pytest.ini_options] are not considered for configuration."""
-        fn = tmpdir.join("myconfig.toml")
-        fn.write(
+        fn = tmp_path / "myconfig.toml"
+        fn.write_text(
             dedent(
                 """
             [build_system]
             x = 1
             """
-            )
+            ),
+            encoding="utf-8",
         )
         assert load_config_dict_from_file(fn) is None
 
-    def test_valid_toml_file(self, tmpdir):
+    def test_valid_toml_file(self, tmp_path: Path) -> None:
         """.toml files with [tool.pytest.ini_options] are read correctly, including changing
         data types to str/list for compatibility with other configuration options."""
-        fn = tmpdir.join("myconfig.toml")
-        fn.write(
+        fn = tmp_path / "myconfig.toml"
+        fn.write_text(
             dedent(
                 """
             [tool.pytest.ini_options]
@@ -77,7 +77,8 @@ class TestLoadConfigDictFromFile:
             values = ["tests", "integration"]
             name = "foo"
             """
-            )
+            ),
+            encoding="utf-8",
         )
         assert load_config_dict_from_file(fn) == {
             "x": "1",
@@ -88,23 +89,22 @@ class TestLoadConfigDictFromFile:
 
 
 class TestCommonAncestor:
-    def test_has_ancestor(self, tmpdir):
-        fn1 = tmpdir.join("foo/bar/test_1.py").ensure(file=1)
-        fn2 = tmpdir.join("foo/zaz/test_2.py").ensure(file=1)
-        assert get_common_ancestor([fn1, fn2]) == tmpdir.join("foo")
-        assert get_common_ancestor([py.path.local(fn1.dirname), fn2]) == tmpdir.join(
-            "foo"
-        )
-        assert get_common_ancestor(
-            [py.path.local(fn1.dirname), py.path.local(fn2.dirname)]
-        ) == tmpdir.join("foo")
-        assert get_common_ancestor([fn1, py.path.local(fn2.dirname)]) == tmpdir.join(
-            "foo"
-        )
-
-    def test_single_dir(self, tmpdir):
-        assert get_common_ancestor([tmpdir]) == tmpdir
-
-    def test_single_file(self, tmpdir):
-        fn = tmpdir.join("foo.py").ensure(file=1)
-        assert get_common_ancestor([fn]) == tmpdir
+    def test_has_ancestor(self, tmp_path: Path) -> None:
+        fn1 = tmp_path / "foo" / "bar" / "test_1.py"
+        fn1.parent.mkdir(parents=True)
+        fn1.touch()
+        fn2 = tmp_path / "foo" / "zaz" / "test_2.py"
+        fn2.parent.mkdir(parents=True)
+        fn2.touch()
+        assert get_common_ancestor([fn1, fn2]) == tmp_path / "foo"
+        assert get_common_ancestor([fn1.parent, fn2]) == tmp_path / "foo"
+        assert get_common_ancestor([fn1.parent, fn2.parent]) == tmp_path / "foo"
+        assert get_common_ancestor([fn1, fn2.parent]) == tmp_path / "foo"
+
+    def test_single_dir(self, tmp_path: Path) -> None:
+        assert get_common_ancestor([tmp_path]) == tmp_path
+
+    def test_single_file(self, tmp_path: Path) -> None:
+        fn = tmp_path / "foo.py"
+        fn.touch()
+        assert get_common_ancestor([fn]) == tmp_path