fix: Path objects are ok for data_file and config_file. #1552

7 files changed, 45 insertions, 18 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index f336cff5..1c27501d 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -27,6 +27,11 @@ Unreleased
   themselves with messages like "Wrote XML report to file.xml" before spewing a
   traceback about their failure.
 
+- Fix: arguments in the public API that name file paths now accept pathlib.Path
+  objects.  This includes the ``data_file`` and ``config_file`` arguments to
+  the Coverage constructor and the ``basename`` argument to CoverageData.
+  Closes `issue 1552`_.
+
 - Fix: In some embedded environments, an IndexError could occur on stop() when
   the originating thread exits before completion.  This is now fixed, thanks to
   `Russell Keith-Magee <pull 1543_>`_, closing `issue 1542`_.
@@ -38,7 +43,7 @@ Unreleased
 .. _pull 1543: https://github.com/nedbat/coveragepy/pull/1543
 .. _pull 1547: https://github.com/nedbat/coveragepy/pull/1547
 .. _pull 1550: https://github.com/nedbat/coveragepy/pull/1550
-
+.. _issue 1552: https://github.com/nedbat/coveragepy/issues/1552
 
 .. scriv-start-here
 
diff --git a/coverage/control.py b/coverage/control.py
index cdea42ee..e385f0e2 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -47,7 +47,7 @@ from coverage.report import render_report
 from coverage.results import Analysis
 from coverage.summary import SummaryReporter
 from coverage.types import (
-    TConfigurable, TConfigSectionIn, TConfigValueIn, TConfigValueOut,
+    FilePath, TConfigurable, TConfigSectionIn, TConfigValueIn, TConfigValueOut,
     TFileDisposition, TLineNo, TMorf,
 )
 from coverage.xmlreport import XmlReporter
@@ -113,13 +113,13 @@ class Coverage(TConfigurable):
 
     def __init__(                       # pylint: disable=too-many-arguments
         self,
-        data_file: Optional[Union[str, DefaultValue]] = DEFAULT_DATAFILE,
+        data_file: Optional[Union[FilePath, DefaultValue]] = DEFAULT_DATAFILE,
         data_suffix: Optional[Union[str, bool]] = None,
         cover_pylib: Optional[bool] = None,
         auto_data: bool = False,
         timid: Optional[bool] = None,
         branch: Optional[bool] = None,
-        config_file: Union[str, bool] = True,
+        config_file: Union[FilePath, bool] = True,
         source: Optional[Iterable[str]] = None,
         source_pkgs: Optional[Iterable[str]] = None,
         omit: Optional[Union[str, Iterable[str]]] = None,
@@ -227,6 +227,8 @@ class Coverage(TConfigurable):
         self._no_disk = data_file is None
         if isinstance(data_file, DefaultValue):
             data_file = None
+        if data_file is not None:
+            data_file = os.fspath(data_file)
 
         # This is injectable by tests.
         self._debug_file: Optional[IO[str]] = None
@@ -267,6 +269,8 @@ class Coverage(TConfigurable):
         self._should_write_debug = True
 
         # Build our configuration from a number of sources.
+        if not isinstance(config_file, bool):
+            config_file = os.fspath(config_file)
         self.config = read_coverage_config(
             config_file=config_file,
             warn=self._warn,
diff --git a/coverage/sqldata.py b/coverage/sqldata.py
index bb26e4d5..15b30ae9 100644
--- a/coverage/sqldata.py
+++ b/coverage/sqldata.py
@@ -31,7 +31,7 @@ from coverage.exceptions import CoverageException, DataError
 from coverage.files import PathAliases
 from coverage.misc import file_be_gone, isolate_module
 from coverage.numbits import numbits_to_nums, numbits_union, nums_to_numbits
-from coverage.types import TArc, TDebugCtl, TLineNo, TWarnFn
+from coverage.types import FilePath, TArc, TDebugCtl, TLineNo, TWarnFn
 from coverage.version import __version__
 
 os = isolate_module(os)
@@ -216,7 +216,7 @@ class CoverageData(AutoReprMixin):
 
     def __init__(
         self,
-        basename: Optional[str] = None,
+        basename: Optional[FilePath] = None,
         suffix: Optional[Union[str, bool]] = None,
         no_disk: bool = False,
         warn: Optional[TWarnFn] = None,
diff --git a/coverage/types.py b/coverage/types.py
index b8135d05..e01f451e 100644
--- a/coverage/types.py
+++ b/coverage/types.py
@@ -7,9 +7,12 @@ Types for use throughout coverage.py.
 
 from __future__ import annotations
 
+import os
+import pathlib
+
 from types import FrameType, ModuleType
 from typing import (
-    Any, Callable, Dict, Iterable, List, Mapping, Optional, Set, Tuple, Union,
+    Any, Callable, Dict, Iterable, List, Mapping, Optional, Set, Tuple, Type, Union,
     TYPE_CHECKING,
 )
 
@@ -23,6 +26,14 @@ else:
     class Protocol:             # pylint: disable=missing-class-docstring
         pass
 
+## File paths
+
+# For arguments that are file paths:
+FilePath = Union[str, os.PathLike]
+# For testing FilePath arguments
+FilePathClasses = [str, pathlib.Path]
+FilePathType = Union[Type[str], Type[pathlib.Path]]
+
 ## Python tracing
 
 class TTraceFn(Protocol):
diff --git a/tests/test_api.py b/tests/test_api.py
index 1c565421..596510eb 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -25,7 +25,7 @@ from coverage.data import line_counts, sorted_lines
 from coverage.exceptions import CoverageException, DataError, NoDataError, NoSource
 from coverage.files import abs_file, relative_filename
 from coverage.misc import import_local_file
-from coverage.types import Protocol, TCovKwargs
+from coverage.types import FilePathClasses, FilePathType, Protocol, TCovKwargs
 
 from tests.coveragetest import CoverageTest, TESTS_DIR, UsingModulesMixin
 from tests.goldtest import contains, doesnt_contain
@@ -221,26 +221,28 @@ class ApiTest(CoverageTest):
         cov.save()
         self.assertFiles(["datatest1.py", ".coverage"])
 
-    def test_datafile_specified(self) -> None:
+    @pytest.mark.parametrize("file_class", FilePathClasses)
+    def test_datafile_specified(self, file_class: FilePathType) -> None:
         # You can specify the data file name.
         self.make_file("datatest2.py", """\
             fooey = 17
             """)
 
         self.assertFiles(["datatest2.py"])
-        cov = coverage.Coverage(data_file="cov.data")
+        cov = coverage.Coverage(data_file=file_class("cov.data"))
         self.start_import_stop(cov, "datatest2")
         cov.save()
         self.assertFiles(["datatest2.py", "cov.data"])
 
-    def test_datafile_and_suffix_specified(self) -> None:
+    @pytest.mark.parametrize("file_class", FilePathClasses)
+    def test_datafile_and_suffix_specified(self, file_class: FilePathType) -> None:
         # You can specify the data file name and suffix.
         self.make_file("datatest3.py", """\
             fooey = 17
             """)
 
         self.assertFiles(["datatest3.py"])
-        cov = coverage.Coverage(data_file="cov.data", data_suffix="14")
+        cov = coverage.Coverage(data_file=file_class("cov.data"), data_suffix="14")
         self.start_import_stop(cov, "datatest3")
         cov.save()
         self.assertFiles(["datatest3.py", "cov.data.14"])
diff --git a/tests/test_config.py b/tests/test_config.py
index d60a4eeb..2ee5eae0 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -6,8 +6,8 @@
 from __future__ import annotations
 
 import sys
-
 from unittest import mock
+
 import pytest
 
 import coverage
@@ -15,6 +15,7 @@ from coverage import Coverage
 from coverage.config import HandyConfigParser
 from coverage.exceptions import ConfigError, CoverageWarning
 from coverage.tomlconfig import TomlConfigParser
+from coverage.types import FilePathClasses, FilePathType
 
 from tests.coveragetest import CoverageTest, UsingModulesMixin
 
@@ -50,7 +51,8 @@ class ConfigTest(CoverageTest):
         assert not cov.config.branch
         assert cov.config.data_file == ".hello_kitty.data"
 
-    def test_named_config_file(self) -> None:
+    @pytest.mark.parametrize("file_class", FilePathClasses)
+    def test_named_config_file(self, file_class: FilePathType) -> None:
         # You can name the config file what you like.
         self.make_file("my_cov.ini", """\
             [run]
@@ -58,7 +60,7 @@ class ConfigTest(CoverageTest):
             ; I wouldn't really use this as a data file...
             data_file = delete.me
             """)
-        cov = coverage.Coverage(config_file="my_cov.ini")
+        cov = coverage.Coverage(config_file=file_class("my_cov.ini"))
         assert cov.config.timid
         assert not cov.config.branch
         assert cov.config.data_file == "delete.me"
diff --git a/tests/test_data.py b/tests/test_data.py
index 1cc64572..ab3f5f5b 100644
--- a/tests/test_data.py
+++ b/tests/test_data.py
@@ -24,7 +24,7 @@ from coverage.data import add_data_to_hash, line_counts
 from coverage.debug import DebugControlString
 from coverage.exceptions import DataError, NoDataError
 from coverage.files import PathAliases, canonical_filename
-from coverage.types import TArc, TLineNo
+from coverage.types import FilePathClasses, FilePathType, TArc, TLineNo
 
 from tests.coveragetest import CoverageTest
 from tests.helpers import assert_count_equal
@@ -621,10 +621,13 @@ class CoverageDataTest(CoverageTest):
 class CoverageDataInTempDirTest(CoverageTest):
     """Tests of CoverageData that need a temporary directory to make files."""
 
-    def test_read_write_lines(self) -> None:
-        covdata1 = DebugCoverageData("lines.dat")
+    @pytest.mark.parametrize("file_class", FilePathClasses)
+    def test_read_write_lines(self, file_class: FilePathType) -> None:
+        self.assert_doesnt_exist("lines.dat")
+        covdata1 = DebugCoverageData(file_class("lines.dat"))
         covdata1.add_lines(LINES_1)
         covdata1.write()
+        self.assert_exists("lines.dat")
 
         covdata2 = DebugCoverageData("lines.dat")
         covdata2.read()