path: root/tests/test_files.py

# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt

"""Tests for files.py"""

import itertools
import os
import os.path
import re
from unittest import mock

import pytest

from coverage import env, files
from coverage.exceptions import ConfigError
from coverage.files import (
    GlobMatcher, ModuleMatcher, PathAliases, TreeMatcher, abs_file,
    actual_path, find_python_files, flat_rootname, globs_to_regex,
)

from tests.coveragetest import CoverageTest
from tests.helpers import os_sep


class FilesTest(CoverageTest):
    """Tests of coverage.files."""

    def abs_path(self, p):
        """Return the absolute path for `p`."""
        return os.path.join(abs_file(os.getcwd()), os.path.normpath(p))

    def test_simple(self):
        self.make_file("hello.py")
        files.set_relative_directory()
        assert files.relative_filename("hello.py") == "hello.py"
        a = self.abs_path("hello.py")
        assert a != "hello.py"
        assert files.relative_filename(a) == "hello.py"

    def test_peer_directories(self):
        self.make_file("sub/proj1/file1.py")
        self.make_file("sub/proj2/file2.py")
        a1 = self.abs_path("sub/proj1/file1.py")
        a2 = self.abs_path("sub/proj2/file2.py")
        d = os.path.normpath("sub/proj1")
        os.chdir(d)
        files.set_relative_directory()
        assert files.relative_filename(a1) == "file1.py"
        assert files.relative_filename(a2) == a2

    def test_filepath_contains_absolute_prefix_twice(self):
        # https://github.com/nedbat/coveragepy/issues/194
        # Build a path that has two pieces matching the absolute path prefix.
        # Technically, this test doesn't do that on Windows, but drive
        # letters make that impractical to achieve.
        files.set_relative_directory()
        d = abs_file(os.curdir)
        trick = os.path.splitdrive(d)[1].lstrip(os.path.sep)
        rel = os.path.join('sub', trick, 'file1.py')
        assert files.relative_filename(abs_file(rel)) == rel

    def test_canonical_filename_ensure_cache_hit(self):
        self.make_file("sub/proj1/file1.py")
        d = actual_path(self.abs_path("sub/proj1"))
        os.chdir(d)
        files.set_relative_directory()
        canonical_path = files.canonical_filename('sub/proj1/file1.py')
        assert canonical_path == self.abs_path('file1.py')
        # After the filename has been converted, it should be in the cache.
        assert 'sub/proj1/file1.py' in files.CANONICAL_FILENAME_CACHE
        assert files.canonical_filename('sub/proj1/file1.py') == self.abs_path('file1.py')

    @pytest.mark.parametrize(
        "curdir, sep", [
            ("/", "/"),
            ("X:\\", "\\"),
        ]
    )
    def test_relative_dir_for_root(self, curdir, sep):
        with mock.patch.object(files.os, 'curdir', new=curdir):
            with mock.patch.object(files.os, 'sep', new=sep):
                with mock.patch('coverage.files.os.path.normcase', return_value=curdir):
                    files.set_relative_directory()
                    assert files.relative_directory() == curdir

    @pytest.mark.parametrize(
        "to_make, to_check, answer", [
            ("a/b/c/foo.py", "a/b/c/foo.py", True),
            ("a/b/c/foo.py", "a/b/c/bar.py", False),
            ("src/files.zip", "src/files.zip/foo.py", True),
            ("src/files.whl", "src/files.whl/foo.py", True),
            ("src/files.egg", "src/files.egg/foo.py", True),
            ("src/files.pex", "src/files.pex/foo.py", True),
            ("src/files.zip", "src/morefiles.zip/foo.py", False),
            ("src/files.pex", "src/files.pex/zipfiles/files.zip/foo.py", True),
        ]
    )
    def test_source_exists(self, to_make, to_check, answer):
        # source_exists won't look inside the zipfile, so it's fine to make
        # an empty file with the zipfile name.
        self.make_file(to_make, "")
        assert files.source_exists(to_check) == answer


@pytest.mark.parametrize("original, flat", [
    ("abc.py", "abc_py"),
    ("hellothere", "hellothere"),
    ("a/b/c.py", "d_86bbcbe134d28fd2_c_py"),
    ("a/b/defghi.py", "d_86bbcbe134d28fd2_defghi_py"),
    ("/a/b/c.py", "d_bb25e0ada04227c6_c_py"),
    ("/a/b/defghi.py", "d_bb25e0ada04227c6_defghi_py"),
    (r"c:\foo\bar.html", "d_e7c107482373f299_bar_html"),
    (r"d:\foo\bar.html", "d_584a05dcebc67b46_bar_html"),
    ("Montréal/☺/conf.py", "d_c840497a2c647ce0_conf_py"),
    ( # original:
        r"c:\lorem\ipsum\quia\dolor\sit\amet\consectetur\adipisci\velit\sed" +
        r"\quia\non\numquam\eius\modi\tempora\incidunt\ut\labore\et\dolore" +
        r"\magnam\aliquam\quaerat\voluptatem\ut\enim\ad\minima\veniam\quis" +
        r"\nostrum\exercitationem\ullam\corporis\suscipit\laboriosam" +
        r"\Montréal\☺\my_program.py",
        # flat:
        "d_e597dfacb73a23d5_my_program_py"
     ),
])
def test_flat_rootname(original, flat):
    assert flat_rootname(original) == flat


def globs_to_regex_params(
    patterns, case_insensitive=False, partial=False, matches=(), nomatches=(),
):
    """Generate parameters for `test_globs_to_regex`.

    `patterns`, `case_insensitive`, and `partial` are arguments for
    `globs_to_regex`.  `matches` is a list of strings that should match, and
    `nomatches` is a list of strings that should not match.

    Everything is yielded so that `test_globs_to_regex` can call
    `globs_to_regex` once and check one result.

    """
    pat_id = "|".join(patterns)
    for text in matches:
        yield pytest.param(
            patterns, case_insensitive, partial, text, True,
            id=f"{pat_id}:ci{case_insensitive}:par{partial}:{text}:match",
        )
    for text in nomatches:
        yield pytest.param(
            patterns, case_insensitive, partial, text, False,
            id=f"{pat_id}:ci{case_insensitive}:par{partial}:{text}:nomatch",
        )

@pytest.mark.parametrize(
    "patterns, case_insensitive, partial, text, result",
    list(itertools.chain.from_iterable([
        globs_to_regex_params(
            ["abc", "xyz"],
            matches=["abc", "xyz", "sub/mod/abc"],
            nomatches=[
                "ABC", "xYz", "abcx", "xabc", "axyz", "xyza", "sub/mod/abcd", "sub/abc/more",
            ],
        ),
        globs_to_regex_params(
            ["abc", "xyz"], case_insensitive=True,
            matches=["abc", "xyz", "Abc", "XYZ", "AbC"],
            nomatches=["abcx", "xabc", "axyz", "xyza"],
        ),
        globs_to_regex_params(
            ["a*c", "x*z"],
            matches=["abc", "xyz", "xYz", "azc", "xaz", "axyzc"],
            nomatches=["ABC", "abcx", "xabc", "axyz", "xyza", "a/c"],
        ),
        globs_to_regex_params(
            ["a?c", "x?z"],
            matches=["abc", "xyz", "xYz", "azc", "xaz"],
            nomatches=["ABC", "abcx", "xabc", "axyz", "xyza", "a/c"],
        ),
        globs_to_regex_params(
            ["a??d"],
            matches=["abcd", "azcd", "a12d"],
            nomatches=["ABCD", "abcx", "axyz", "abcde"],
        ),
        globs_to_regex_params(
            ["abc/hi.py"], case_insensitive=True,
            matches=["abc/hi.py", "ABC/hi.py", r"ABC\hi.py"],
            nomatches=["abc_hi.py", "abc/hi.pyc"],
        ),
        globs_to_regex_params(
            [r"abc\hi.py"], case_insensitive=True,
            matches=[r"abc\hi.py", r"ABC\hi.py", "abc/hi.py", "ABC/hi.py"],
            nomatches=["abc_hi.py", "abc/hi.pyc"],
        ),
        globs_to_regex_params(
            ["abc/*/hi.py"], case_insensitive=True,
            matches=["abc/foo/hi.py", r"ABC\foo/hi.py"],
            nomatches=["abc/hi.py", "abc/hi.pyc", "ABC/foo/bar/hi.py", r"ABC\foo/bar/hi.py"],
        ),
        globs_to_regex_params(
            ["abc/**/hi.py"], case_insensitive=True,
            matches=[
                "abc/foo/hi.py", r"ABC\foo/hi.py", "abc/hi.py", "ABC/foo/bar/hi.py",
                r"ABC\foo/bar/hi.py",
            ],
            nomatches=["abc/hi.pyc"],
        ),
        globs_to_regex_params(
            ["abc/[a-f]*/hi.py"], case_insensitive=True,
            matches=["abc/foo/hi.py", r"ABC\boo/hi.py"],
            nomatches=[
                "abc/zoo/hi.py", "abc/hi.py", "abc/hi.pyc", "abc/foo/bar/hi.py",
                r"abc\foo/bar/hi.py",
            ],
        ),
        globs_to_regex_params(
            ["abc/[a-f]/hi.py"], case_insensitive=True,
            matches=["abc/f/hi.py", r"ABC\b/hi.py"],
            nomatches=[
                "abc/foo/hi.py", "abc/zoo/hi.py", "abc/hi.py", "abc/hi.pyc", "abc/foo/bar/hi.py",
                r"abc\foo/bar/hi.py",
            ],
        ),
        globs_to_regex_params(
            ["abc/"], case_insensitive=True, partial=True,
            matches=["abc/foo/hi.py", "ABC/foo/bar/hi.py", r"ABC\foo/bar/hi.py"],
            nomatches=["abcd/foo.py", "xabc/hi.py"],
        ),
        globs_to_regex_params(
            ["*/foo"], case_insensitive=False, partial=True,
            matches=["abc/foo/hi.py", "foo/hi.py"],
            nomatches=["abc/xfoo/hi.py"],
        ),
        globs_to_regex_params(
            ["**/foo"],
            matches=["foo", "hello/foo", "hi/there/foo"],
            nomatches=["foob", "hello/foob", "hello/Foo"],
        ),
        globs_to_regex_params(
            ["a+b/foo*", "x{y}z/foo*"],
            matches=["a+b/foo", "a+b/foobar", "x{y}z/foobar"],
            nomatches=["aab/foo", "ab/foo", "xyz/foo"],
        ),
    ]))
)
def test_globs_to_regex(patterns, case_insensitive, partial, text, result):
    regex = globs_to_regex(patterns, case_insensitive=case_insensitive, partial=partial)
    print(patterns)
    print(regex)
    print(text)
    assert bool(regex.match(text)) == result


@pytest.mark.parametrize("pattern, bad_word", [
    ("***/foo.py", "***"),
    ("bar/***/foo.py", "***"),
    ("*****/foo.py", "*****"),
    ("Hello]there", "]"),
    ("Hello[there", "["),
    ("x/a**/b.py", "a**"),
    ("x/abcd**/b.py", "abcd**"),
    ("x/**a/b.py", "**a"),
    ("x/**/**/b.py", "**/**"),
])
def test_invalid_globs(pattern, bad_word):
    msg = f"File pattern can't include {bad_word!r}"
    with pytest.raises(ConfigError, match=re.escape(msg)):
        globs_to_regex([pattern])


class MatcherTest(CoverageTest):
    """Tests of file matchers."""

    def setUp(self):
        super().setUp()
        files.set_relative_directory()

    def assertMatches(self, matcher, filepath, matches):
        """The `matcher` should agree with `matches` about `filepath`."""
        canonical = files.canonical_filename(filepath)
        msg = f"File {filepath} should have matched as {matches}"
        assert matches == matcher.match(canonical), msg

    def test_tree_matcher(self):
        case_folding = env.WINDOWS
        matches_to_try = [
            (self.make_file("sub/file1.py"), True),
            (self.make_file("sub/file2.c"), True),
            (self.make_file("sub2/file3.h"), False),
            (self.make_file("sub3/file4.py"), True),
            (self.make_file("sub3/file5.c"), False),
            (self.make_file("sub4/File5.py"), case_folding),
            (self.make_file("sub5/file6.py"), case_folding),
        ]
        trees = [
            files.canonical_filename("sub"),
            files.canonical_filename("sub3/file4.py"),
            files.canonical_filename("sub4/file5.py"),
            files.canonical_filename("SUB5/file6.py"),
        ]
        tm = TreeMatcher(trees)
        assert tm.info() == sorted(trees)
        for filepath, matches in matches_to_try:
            self.assertMatches(tm, filepath, matches)

    def test_module_matcher(self):
        matches_to_try = [
            ('test', True),
            ('trash', False),
            ('testing', False),
            ('test.x', True),
            ('test.x.y.z', True),
            ('py', False),
            ('py.t', False),
            ('py.test', True),
            ('py.testing', False),
            ('py.test.buz', True),
            ('py.test.buz.baz', True),
            ('__main__', False),
            ('mymain', True),
            ('yourmain', False),
        ]
        modules = ['test', 'py.test', 'mymain']
        mm = ModuleMatcher(modules)
        assert mm.info() == modules
        for modulename, matches in matches_to_try:
            assert mm.match(modulename) == matches, modulename

    def test_glob_matcher(self):
        matches_to_try = [
            (self.make_file("sub/file1.py"), True),
            (self.make_file("sub/file2.c"), False),
            (self.make_file("sub2/file3.h"), True),
            (self.make_file("sub3/file4.py"), True),
            (self.make_file("sub3/file5.c"), False),
        ]
        fnm = GlobMatcher(["*.py", "*/sub2/*"])
        assert fnm.info() == ["*.py", "*/sub2/*"]
        for filepath, matches in matches_to_try:
            self.assertMatches(fnm, filepath, matches)

    def test_glob_matcher_overload(self):
        fnm = GlobMatcher(["*x%03d*.txt" % i for i in range(500)])
        self.assertMatches(fnm, "x007foo.txt", True)
        self.assertMatches(fnm, "x123foo.txt", True)
        self.assertMatches(fnm, "x798bar.txt", False)
        self.assertMatches(fnm, "x499.txt", True)
        self.assertMatches(fnm, "x500.txt", False)

    def test_glob_windows_paths(self):
        # We should be able to match Windows paths even if we are running on
        # a non-Windows OS.
        fnm = GlobMatcher(["*/foo.py"])
        self.assertMatches(fnm, r"dir\foo.py", True)
        fnm = GlobMatcher([r"*\foo.py"])
        self.assertMatches(fnm, r"dir\foo.py", True)


@pytest.fixture(params=[False, True], name="rel_yn")
def relative_setting(request):
    """Parameterized fixture to choose whether PathAliases is relative or not."""
    return request.param


class PathAliasesTest(CoverageTest):
    """Tests for coverage/files.py:PathAliases"""

    run_in_temp_dir = False

    def assert_mapped(self, aliases, inp, out):
        """Assert that `inp` mapped through `aliases` produces `out`.

        If the aliases are not relative, then `out` is canonicalized first,
        since aliases produce canonicalized paths by default.

        """
        mapped = aliases.map(inp, exists=lambda p: True)
        if aliases.relative:
            expected = out
        else:
            expected = files.canonical_filename(out)
        assert mapped == expected

    def assert_unchanged(self, aliases, inp, exists=True):
        """Assert that `inp` mapped through `aliases` is unchanged."""
        assert aliases.map(inp, exists=lambda p: exists) == inp

    def test_noop(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        self.assert_unchanged(aliases, '/ned/home/a.py')

    def test_nomatch(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('/home/*/src', './mysrc')
        self.assert_unchanged(aliases, '/home/foo/a.py')

    def test_wildcard(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('/ned/home/*/src', './mysrc')
        self.assert_mapped(aliases, '/ned/home/foo/src/a.py', './mysrc/a.py')

        aliases = PathAliases(relative=rel_yn)
        aliases.add('/ned/home/*/src/', './mysrc')
        self.assert_mapped(aliases, '/ned/home/foo/src/a.py', './mysrc/a.py')

    def test_no_accidental_match(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('/home/*/src', './mysrc')
        self.assert_unchanged(aliases, '/home/foo/srcetc')

    def test_no_map_if_not_exist(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('/ned/home/*/src', './mysrc')
        self.assert_unchanged(aliases, '/ned/home/foo/src/a.py', exists=False)
        self.assert_unchanged(aliases, 'foo/src/a.py', exists=False)

    def test_no_dotslash(self, rel_yn):
        # The result shouldn't start with "./" if the map result didn't.
        aliases = PathAliases(relative=rel_yn)
        aliases.add('*/project', '.')
        self.assert_mapped(aliases, '/ned/home/project/src/a.py', os_sep('src/a.py'))

    def test_relative_pattern(self):
        aliases = PathAliases(relative=True)
        aliases.add(".tox/*/site-packages", "src")
        self.assert_mapped(
            aliases,
            ".tox/py314/site-packages/proj/a.py",
            os_sep("src/proj/a.py"),
        )

    def test_multiple_patterns(self, rel_yn):
        # also test the debugfn...
        msgs = []
        aliases = PathAliases(debugfn=msgs.append, relative=rel_yn)
        aliases.add('/home/*/src', './mysrc')
        aliases.add('/lib/*/libsrc', './mylib')
        self.assert_mapped(aliases, '/home/foo/src/a.py', './mysrc/a.py')
        self.assert_mapped(aliases, '/lib/foo/libsrc/a.py', './mylib/a.py')
        if rel_yn:
            assert msgs == [
                "Aliases (relative=True):",
                " Rule: '/home/*/src' -> './mysrc/' using regex " +
                    "'[/\\\\\\\\]home[/\\\\\\\\][^/\\\\\\\\]*[/\\\\\\\\]src[/\\\\\\\\]'",
                " Rule: '/lib/*/libsrc' -> './mylib/' using regex " +
                    "'[/\\\\\\\\]lib[/\\\\\\\\][^/\\\\\\\\]*[/\\\\\\\\]libsrc[/\\\\\\\\]'",
                "Matched path '/home/foo/src/a.py' to rule '/home/*/src' -> './mysrc/', " +
                    "producing './mysrc/a.py'",
                "Matched path '/lib/foo/libsrc/a.py' to rule '/lib/*/libsrc' -> './mylib/', " +
                    "producing './mylib/a.py'",
            ]
        else:
            assert msgs == [
                "Aliases (relative=False):",
                " Rule: '/home/*/src' -> './mysrc/' using regex " +
                    "'[/\\\\\\\\]home[/\\\\\\\\][^/\\\\\\\\]*[/\\\\\\\\]src[/\\\\\\\\]'",
                " Rule: '/lib/*/libsrc' -> './mylib/' using regex " +
                    "'[/\\\\\\\\]lib[/\\\\\\\\][^/\\\\\\\\]*[/\\\\\\\\]libsrc[/\\\\\\\\]'",
                "Matched path '/home/foo/src/a.py' to rule '/home/*/src' -> './mysrc/', " +
                    f"producing {files.canonical_filename('./mysrc/a.py')!r}",
                "Matched path '/lib/foo/libsrc/a.py' to rule '/lib/*/libsrc' -> './mylib/', " +
                    f"producing {files.canonical_filename('./mylib/a.py')!r}",
            ]

    @pytest.mark.parametrize("badpat", [
        "/ned/home/*",
        "/ned/home/*/",
        "/ned/home/*/*/",
    ])
    def test_cant_have_wildcard_at_end(self, badpat):
        aliases = PathAliases()
        msg = "Pattern must not end with wildcards."
        with pytest.raises(ConfigError, match=msg):
            aliases.add(badpat, "fooey")

    def test_no_accidental_munging(self):
        aliases = PathAliases()
        aliases.add(r'c:\Zoo\boo', 'src/')
        aliases.add('/home/ned$', 'src/')
        self.assert_mapped(aliases, r'c:\Zoo\boo\foo.py', 'src/foo.py')
        self.assert_mapped(aliases, r'/home/ned$/foo.py', 'src/foo.py')

    def test_paths_are_os_corrected(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('/home/ned/*/src', './mysrc')
        aliases.add(r'c:\ned\src', './mysrc')
        self.assert_mapped(aliases, r'C:\Ned\src\sub\a.py', './mysrc/sub/a.py')

        aliases = PathAliases(relative=rel_yn)
        aliases.add('/home/ned/*/src', r'.\mysrc')
        aliases.add(r'c:\ned\src', r'.\mysrc')
        self.assert_mapped(
            aliases,
            r'/home/ned/foo/src/sub/a.py',
            r'.\mysrc\sub\a.py',
        )

    # Try the paths in both orders.
    lin = "*/project/module/"
    win = "*\\project\\module\\"
    lin_win_paths = [[lin, win], [win, lin]]

    @pytest.mark.parametrize("paths", lin_win_paths)
    def test_windows_on_linux(self, paths, rel_yn):
        # https://github.com/nedbat/coveragepy/issues/618
        aliases = PathAliases(relative=rel_yn)
        for path in paths:
            aliases.add(path, "project/module")
        self.assert_mapped(
            aliases,
            "C:\\a\\path\\somewhere\\coveragepy_test\\project\\module\\tests\\file.py",
            "project/module/tests/file.py",
        )

    @pytest.mark.parametrize("paths", lin_win_paths)
    def test_linux_on_windows(self, paths, rel_yn):
        # https://github.com/nedbat/coveragepy/issues/618
        aliases = PathAliases(relative=rel_yn)
        for path in paths:
            aliases.add(path, "project\\module")
        self.assert_mapped(
            aliases,
            "C:/a/path/somewhere/coveragepy_test/project/module/tests/file.py",
            "project\\module\\tests\\file.py",
        )

    @pytest.mark.parametrize("paths", lin_win_paths)
    def test_relative_windows_on_linux(self, paths):
        # https://github.com/nedbat/coveragepy/issues/991
        aliases = PathAliases(relative=True)
        for path in paths:
            aliases.add(path, "project/module")
        self.assert_mapped(
            aliases,
            r"project\module\tests\file.py",
            r"project/module/tests/file.py",
        )

    @pytest.mark.parametrize("paths", lin_win_paths)
    def test_relative_linux_on_windows(self, paths):
        # https://github.com/nedbat/coveragepy/issues/991
        aliases = PathAliases(relative=True)
        for path in paths:
            aliases.add(path, r"project\module")
        self.assert_mapped(
            aliases,
            r"project/module/tests/file.py",
            r"project\module\tests\file.py",
        )

    @pytest.mark.skipif(env.WINDOWS, reason="This test assumes Unix file system")
    def test_implicit_relative_windows_on_linux(self):
        # https://github.com/nedbat/coveragepy/issues/991
        aliases = PathAliases(relative=True)
        self.assert_mapped(
            aliases,
            r"project\module\tests\file.py",
            r"project/module/tests/file.py",
        )

    @pytest.mark.skipif(not env.WINDOWS, reason="This test assumes Windows file system")
    def test_implicit_relative_linux_on_windows(self):
        # https://github.com/nedbat/coveragepy/issues/991
        aliases = PathAliases(relative=True)
        self.assert_mapped(
            aliases,
            r"project/module/tests/file.py",
            r"project\module\tests\file.py",
        )

    def test_multiple_wildcard(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('/home/jenkins/*/a/*/b/*/django', './django')
        self.assert_mapped(
            aliases,
            '/home/jenkins/xx/a/yy/b/zz/django/foo/bar.py',
            './django/foo/bar.py',
        )

    def test_windows_root_paths(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('X:\\', '/tmp/src')
        self.assert_mapped(
            aliases,
            "X:\\a\\file.py",
            "/tmp/src/a/file.py",
        )
        self.assert_mapped(
            aliases,
            "X:\\file.py",
            "/tmp/src/file.py",
        )

    def test_leading_wildcard(self, rel_yn):
        aliases = PathAliases(relative=rel_yn)
        aliases.add('*/d1', './mysrc1')
        aliases.add('*/d2', './mysrc2')
        self.assert_mapped(aliases, '/foo/bar/d1/x.py', './mysrc1/x.py')
        self.assert_mapped(aliases, '/foo/bar/d2/y.py', './mysrc2/y.py')

    @pytest.mark.parametrize("dirname", [".", "..", "../other", "/"])
    def test_dot(self, dirname):
        if env.WINDOWS and dirname == "/":
            # The root test case was added for the manylinux Docker images,
            # and I'm not sure how it should work on Windows, so skip it.
            pytest.skip("Don't know how to handle root on Windows")
        aliases = PathAliases()
        aliases.add(dirname, '/the/source')
        the_file = os.path.join(dirname, 'a.py')
        the_file = os.path.expanduser(the_file)
        the_file = os.path.abspath(os.path.realpath(the_file))

        assert '~' not in the_file  # to be sure the test is pure.
        self.assert_mapped(aliases, the_file, '/the/source/a.py')


class PathAliasesRealFilesTest(CoverageTest):
    """Tests for coverage/files.py:PathAliases using real files."""

    def test_aliasing_zip_files(self):
        self.make_file("src/zipfiles/code.zip", "fake zip, doesn't matter")
        aliases = PathAliases()
        aliases.add("*/d1", "./src")
        aliases.add("*/d2", "./src")

        expected = files.canonical_filename("src/zipfiles/code.zip/p1.py")
        assert aliases.map("tox/d1/zipfiles/code.zip/p1.py") == expected


class FindPythonFilesTest(CoverageTest):
    """Tests of `find_python_files`."""

    def test_find_python_files(self):
        self.make_file("sub/a.py")
        self.make_file("sub/b.py")
        self.make_file("sub/x.c")                   # nope: not .py
        self.make_file("sub/ssub/__init__.py")
        self.make_file("sub/ssub/s.py")
        self.make_file("sub/ssub/~s.py")            # nope: editor effluvia
        self.make_file("sub/lab/exp.py")            # nope: no __init__.py
        self.make_file("sub/windows.pyw")
        py_files = set(find_python_files("sub", include_namespace_packages=False))
        self.assert_same_files(py_files, [
            "sub/a.py", "sub/b.py",
            "sub/ssub/__init__.py", "sub/ssub/s.py",
            "sub/windows.pyw",
        ])

    def test_find_python_files_include_namespace_packages(self):
        self.make_file("sub/a.py")
        self.make_file("sub/b.py")
        self.make_file("sub/x.c")                   # nope: not .py
        self.make_file("sub/ssub/__init__.py")
        self.make_file("sub/ssub/s.py")
        self.make_file("sub/ssub/~s.py")            # nope: editor effluvia
        self.make_file("sub/lab/exp.py")
        self.make_file("sub/windows.pyw")
        py_files = set(find_python_files("sub", include_namespace_packages=True))
        self.assert_same_files(py_files, [
            "sub/a.py", "sub/b.py",
            "sub/ssub/__init__.py", "sub/ssub/s.py",
            "sub/lab/exp.py",
            "sub/windows.pyw",
        ])


@pytest.mark.skipif(not env.WINDOWS, reason="Only need to run Windows tests on Windows.")
class WindowsFileTest(CoverageTest):
    """Windows-specific tests of file name handling."""

    run_in_temp_dir = False

    def test_actual_path(self):
        assert actual_path(r'c:\Windows') == actual_path(r'C:\wINDOWS')