django/tests/file_storage/tests.py

import os
import shutil
import sys
import tempfile
import threading
import time
import unittest
from datetime import datetime, timedelta
from datetime import timezone as datetime_timezone
from io import StringIO
from pathlib import Path
from urllib.request import urlopen

from django.conf import DEFAULT_STORAGE_ALIAS, STATICFILES_STORAGE_ALIAS
from django.core.cache import cache
from django.core.exceptions import SuspiciousFileOperation
from django.core.files.base import ContentFile, File
from django.core.files.storage import FileSystemStorage, InvalidStorageError
from django.core.files.storage import Storage as BaseStorage
from django.core.files.storage import StorageHandler, default_storage, storages
from django.core.files.uploadedfile import (
    InMemoryUploadedFile,
    SimpleUploadedFile,
    TemporaryUploadedFile,
)
from django.db.models import FileField
from django.db.models.fields.files import FileDescriptor
from django.test import (
    LiveServerTestCase,
    SimpleTestCase,
    TestCase,
    ignore_warnings,
    override_settings,
)
from django.test.utils import requires_tz_support
from django.urls import NoReverseMatch, reverse_lazy
from django.utils import timezone
from django.utils._os import symlinks_supported
from django.utils.deprecation import RemovedInDjango60Warning

from .models import (
    Storage,
    callable_default_storage,
    callable_storage,
    temp_storage,
    temp_storage_location,
)

FILE_SUFFIX_REGEX = "[A-Za-z0-9]{7}"


class FileSystemStorageTests(unittest.TestCase):
    def test_deconstruction(self):
        path, args, kwargs = temp_storage.deconstruct()
        self.assertEqual(path, "django.core.files.storage.FileSystemStorage")
        self.assertEqual(args, ())
        self.assertEqual(kwargs, {"location": temp_storage_location})

        kwargs_orig = {
            "location": temp_storage_location,
            "base_url": "http://myfiles.example.com/",
        }
        storage = FileSystemStorage(**kwargs_orig)
        path, args, kwargs = storage.deconstruct()
        self.assertEqual(kwargs, kwargs_orig)

    def test_lazy_base_url_init(self):
        """
        FileSystemStorage.__init__() shouldn't evaluate base_url.
        """
        storage = FileSystemStorage(base_url=reverse_lazy("app:url"))
        with self.assertRaises(NoReverseMatch):
            storage.url(storage.base_url)


class FileStorageTests(SimpleTestCase):
    storage_class = FileSystemStorage

    def setUp(self):
        self.temp_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.temp_dir)
        self.storage = self.storage_class(
            location=self.temp_dir, base_url="/test_media_url/"
        )

    def test_empty_location(self):
        """
        Makes sure an exception is raised if the location is empty
        """
        storage = self.storage_class(location="")
        self.assertEqual(storage.base_location, "")
        self.assertEqual(storage.location, os.getcwd())

    def test_file_access_options(self):
        """
        Standard file access options are available, and work as expected.
        """
        self.assertFalse(self.storage.exists("storage_test"))
        f = self.storage.open("storage_test", "w")
        f.write("storage contents")
        f.close()
        self.assertTrue(self.storage.exists("storage_test"))

        f = self.storage.open("storage_test", "r")
        self.assertEqual(f.read(), "storage contents")
        f.close()

        self.storage.delete("storage_test")
        self.assertFalse(self.storage.exists("storage_test"))

    def _test_file_time_getter(self, getter):
        # Check for correct behavior under both USE_TZ=True and USE_TZ=False.
        # The tests are similar since they both set up a situation where the
        # system time zone, Django's TIME_ZONE, and UTC are distinct.
        self._test_file_time_getter_tz_handling_on(getter)
        self._test_file_time_getter_tz_handling_off(getter)

    @override_settings(USE_TZ=True, TIME_ZONE="Africa/Algiers")
    def _test_file_time_getter_tz_handling_on(self, getter):
        # Django's TZ (and hence the system TZ) is set to Africa/Algiers which
        # is UTC+1 and has no DST change. We can set the Django TZ to something
        # else so that UTC, Django's TIME_ZONE, and the system timezone are all
        # different.
        now_in_algiers = timezone.make_aware(datetime.now())

        with timezone.override(timezone.get_fixed_timezone(-300)):
            # At this point the system TZ is +1 and the Django TZ
            # is -5. The following will be aware in UTC.
            now = timezone.now()
            self.assertFalse(self.storage.exists("test.file.tz.on"))

            f = ContentFile("custom contents")
            f_name = self.storage.save("test.file.tz.on", f)
            self.addCleanup(self.storage.delete, f_name)
            dt = getter(f_name)
            # dt should be aware, in UTC
            self.assertTrue(timezone.is_aware(dt))
            self.assertEqual(now.tzname(), dt.tzname())

            # The three timezones are indeed distinct.
            naive_now = datetime.now()
            algiers_offset = now_in_algiers.tzinfo.utcoffset(naive_now)
            django_offset = timezone.get_current_timezone().utcoffset(naive_now)
            utc_offset = datetime_timezone.utc.utcoffset(naive_now)
            self.assertGreater(algiers_offset, utc_offset)
            self.assertLess(django_offset, utc_offset)

            # dt and now should be the same effective time.
            self.assertLess(abs(dt - now), timedelta(seconds=2))

    @override_settings(USE_TZ=False, TIME_ZONE="Africa/Algiers")
    def _test_file_time_getter_tz_handling_off(self, getter):
        # Django's TZ (and hence the system TZ) is set to Africa/Algiers which
        # is UTC+1 and has no DST change. We can set the Django TZ to something
        # else so that UTC, Django's TIME_ZONE, and the system timezone are all
        # different.
        now_in_algiers = timezone.make_aware(datetime.now())

        with timezone.override(timezone.get_fixed_timezone(-300)):
            # At this point the system TZ is +1 and the Django TZ
            # is -5.
            self.assertFalse(self.storage.exists("test.file.tz.off"))

            f = ContentFile("custom contents")
            f_name = self.storage.save("test.file.tz.off", f)
            self.addCleanup(self.storage.delete, f_name)
            dt = getter(f_name)
            # dt should be naive, in system (+1) TZ
            self.assertTrue(timezone.is_naive(dt))

            # The three timezones are indeed distinct.
            naive_now = datetime.now()
            algiers_offset = now_in_algiers.tzinfo.utcoffset(naive_now)
            django_offset = timezone.get_current_timezone().utcoffset(naive_now)
            utc_offset = datetime_timezone.utc.utcoffset(naive_now)
            self.assertGreater(algiers_offset, utc_offset)
            self.assertLess(django_offset, utc_offset)

            # dt and naive_now should be the same effective time.
            self.assertLess(abs(dt - naive_now), timedelta(seconds=2))
            # If we convert dt to an aware object using the Algiers
            # timezone then it should be the same effective time to
            # now_in_algiers.
            _dt = timezone.make_aware(dt, now_in_algiers.tzinfo)
            self.assertLess(abs(_dt - now_in_algiers), timedelta(seconds=2))

    def test_file_get_accessed_time(self):
        """
        File storage returns a Datetime object for the last accessed time of
        a file.
        """
        self.assertFalse(self.storage.exists("test.file"))

        f = ContentFile("custom contents")
        f_name = self.storage.save("test.file", f)
        self.addCleanup(self.storage.delete, f_name)
        atime = self.storage.get_accessed_time(f_name)

        self.assertEqual(
            atime, datetime.fromtimestamp(os.path.getatime(self.storage.path(f_name)))
        )
        self.assertLess(
            timezone.now() - self.storage.get_accessed_time(f_name),
            timedelta(seconds=2),
        )

    @requires_tz_support
    def test_file_get_accessed_time_timezone(self):
        self._test_file_time_getter(self.storage.get_accessed_time)

    def test_file_get_created_time(self):
        """
        File storage returns a datetime for the creation time of a file.
        """
        self.assertFalse(self.storage.exists("test.file"))

        f = ContentFile("custom contents")
        f_name = self.storage.save("test.file", f)
        self.addCleanup(self.storage.delete, f_name)
        ctime = self.storage.get_created_time(f_name)

        self.assertEqual(
            ctime, datetime.fromtimestamp(os.path.getctime(self.storage.path(f_name)))
        )
        self.assertLess(
            timezone.now() - self.storage.get_created_time(f_name), timedelta(seconds=2)
        )

    @requires_tz_support
    def test_file_get_created_time_timezone(self):
        self._test_file_time_getter(self.storage.get_created_time)

    def test_file_get_modified_time(self):
        """
        File storage returns a datetime for the last modified time of a file.
        """
        self.assertFalse(self.storage.exists("test.file"))

        f = ContentFile("custom contents")
        f_name = self.storage.save("test.file", f)
        self.addCleanup(self.storage.delete, f_name)
        mtime = self.storage.get_modified_time(f_name)

        self.assertEqual(
            mtime, datetime.fromtimestamp(os.path.getmtime(self.storage.path(f_name)))
        )
        self.assertLess(
            timezone.now() - self.storage.get_modified_time(f_name),
            timedelta(seconds=2),
        )

    @requires_tz_support
    def test_file_get_modified_time_timezone(self):
        self._test_file_time_getter(self.storage.get_modified_time)

    def test_file_save_without_name(self):
        """
        File storage extracts the filename from the content object if no
        name is given explicitly.
        """
        self.assertFalse(self.storage.exists("test.file"))

        f = ContentFile("custom contents")
        f.name = "test.file"

        storage_f_name = self.storage.save(None, f)

        self.assertEqual(storage_f_name, f.name)

        self.assertTrue(os.path.exists(os.path.join(self.temp_dir, f.name)))

        self.storage.delete(storage_f_name)

    def test_file_save_with_path(self):
        """
        Saving a pathname should create intermediate directories as necessary.
        """
        self.assertFalse(self.storage.exists("path/to"))
        self.storage.save("path/to/test.file", ContentFile("file saved with path"))

        self.assertTrue(self.storage.exists("path/to"))
        with self.storage.open("path/to/test.file") as f:
            self.assertEqual(f.read(), b"file saved with path")

        self.assertTrue(
            os.path.exists(os.path.join(self.temp_dir, "path", "to", "test.file"))
        )

        self.storage.delete("path/to/test.file")

    @unittest.skipUnless(
        symlinks_supported(), "Must be able to symlink to run this test."
    )
    def test_file_save_broken_symlink(self):
        """A new path is created on save when a broken symlink is supplied."""
        nonexistent_file_path = os.path.join(self.temp_dir, "nonexistent.txt")
        broken_symlink_file_name = "symlink.txt"
        broken_symlink_path = os.path.join(self.temp_dir, broken_symlink_file_name)
        os.symlink(nonexistent_file_path, broken_symlink_path)
        f = ContentFile("some content")
        f_name = self.storage.save(broken_symlink_file_name, f)
        self.assertIs(os.path.exists(os.path.join(self.temp_dir, f_name)), True)

    def test_save_doesnt_close(self):
        with TemporaryUploadedFile("test", "text/plain", 1, "utf8") as file:
            file.write(b"1")
            file.seek(0)
            self.assertFalse(file.closed)
            self.storage.save("path/to/test.file", file)
            self.assertFalse(file.closed)
            self.assertFalse(file.file.closed)

        file = InMemoryUploadedFile(StringIO("1"), "", "test", "text/plain", 1, "utf8")
        with file:
            self.assertFalse(file.closed)
            self.storage.save("path/to/test.file", file)
            self.assertFalse(file.closed)
            self.assertFalse(file.file.closed)

    def test_file_path(self):
        """
        File storage returns the full path of a file
        """
        self.assertFalse(self.storage.exists("test.file"))

        f = ContentFile("custom contents")
        f_name = self.storage.save("test.file", f)

        self.assertEqual(self.storage.path(f_name), os.path.join(self.temp_dir, f_name))

        self.storage.delete(f_name)

    def test_file_url(self):
        """
        File storage returns a url to access a given file from the web.
        """
        self.assertEqual(
            self.storage.url("test.file"), self.storage.base_url + "test.file"
        )

        # should encode special chars except ~!*()'
        # like encodeURIComponent() JavaScript function do
        self.assertEqual(
            self.storage.url(r"~!*()'@#$%^&*abc`+ =.file"),
            "/test_media_url/~!*()'%40%23%24%25%5E%26*abc%60%2B%20%3D.file",
        )
        self.assertEqual(self.storage.url("ab\0c"), "/test_media_url/ab%00c")

        # should translate os path separator(s) to the url path separator
        self.assertEqual(
            self.storage.url("""a/b\\c.file"""), "/test_media_url/a/b/c.file"
        )

        # #25905: remove leading slashes from file names to prevent unsafe url output
        self.assertEqual(self.storage.url("/evil.com"), "/test_media_url/evil.com")
        self.assertEqual(self.storage.url(r"\evil.com"), "/test_media_url/evil.com")
        self.assertEqual(self.storage.url("///evil.com"), "/test_media_url/evil.com")
        self.assertEqual(self.storage.url(r"\\\evil.com"), "/test_media_url/evil.com")

        self.assertEqual(self.storage.url(None), "/test_media_url/")

    def test_base_url(self):
        """
        File storage returns a url even when its base_url is unset or modified.
        """
        self.storage.base_url = None
        with self.assertRaises(ValueError):
            self.storage.url("test.file")

        # #22717: missing ending slash in base_url should be auto-corrected
        storage = self.storage_class(
            location=self.temp_dir, base_url="/no_ending_slash"
        )
        self.assertEqual(
            storage.url("test.file"), "%s%s" % (storage.base_url, "test.file")
        )

    def test_listdir(self):
        """
        File storage returns a tuple containing directories and files.
        """
        self.assertFalse(self.storage.exists("storage_test_1"))
        self.assertFalse(self.storage.exists("storage_test_2"))
        self.assertFalse(self.storage.exists("storage_dir_1"))

        self.storage.save("storage_test_1", ContentFile("custom content"))
        self.storage.save("storage_test_2", ContentFile("custom content"))
        os.mkdir(os.path.join(self.temp_dir, "storage_dir_1"))

        self.addCleanup(self.storage.delete, "storage_test_1")
        self.addCleanup(self.storage.delete, "storage_test_2")

        for directory in ("", Path("")):
            with self.subTest(directory=directory):
                dirs, files = self.storage.listdir(directory)
                self.assertEqual(set(dirs), {"storage_dir_1"})
                self.assertEqual(set(files), {"storage_test_1", "storage_test_2"})

    def test_file_storage_prevents_directory_traversal(self):
        """
        File storage prevents directory traversal (files can only be accessed if
        they're below the storage location).
        """
        with self.assertRaises(SuspiciousFileOperation):
            self.storage.exists("..")
        with self.assertRaises(SuspiciousFileOperation):
            self.storage.exists("/etc/passwd")

    def test_file_storage_preserves_filename_case(self):
        """The storage backend should preserve case of filenames."""
        # Create a storage backend associated with the mixed case name
        # directory.
        temp_dir2 = tempfile.mkdtemp(suffix="aBc")
        self.addCleanup(shutil.rmtree, temp_dir2)
        other_temp_storage = self.storage_class(location=temp_dir2)
        # Ask that storage backend to store a file with a mixed case filename.
        mixed_case = "CaSe_SeNsItIvE"
        file = other_temp_storage.open(mixed_case, "w")
        file.write("storage contents")
        file.close()
        self.assertEqual(
            os.path.join(temp_dir2, mixed_case),
            other_temp_storage.path(mixed_case),
        )
        other_temp_storage.delete(mixed_case)

    def test_makedirs_race_handling(self):
        """
        File storage should be robust against directory creation race conditions.
        """
        real_makedirs = os.makedirs

        # Monkey-patch os.makedirs, to simulate a normal call, a raced call,
        # and an error.
        def fake_makedirs(path, mode=0o777, exist_ok=False):
            if path == os.path.join(self.temp_dir, "normal"):
                real_makedirs(path, mode, exist_ok)
            elif path == os.path.join(self.temp_dir, "raced"):
                real_makedirs(path, mode, exist_ok)
                if not exist_ok:
                    raise FileExistsError()
            elif path == os.path.join(self.temp_dir, "error"):
                raise PermissionError()
            else:
                self.fail("unexpected argument %r" % path)

        try:
            os.makedirs = fake_makedirs

            self.storage.save("normal/test.file", ContentFile("saved normally"))
            with self.storage.open("normal/test.file") as f:
                self.assertEqual(f.read(), b"saved normally")

            self.storage.save("raced/test.file", ContentFile("saved with race"))
            with self.storage.open("raced/test.file") as f:
                self.assertEqual(f.read(), b"saved with race")

            # Exceptions aside from FileExistsError are raised.
            with self.assertRaises(PermissionError):
                self.storage.save("error/test.file", ContentFile("not saved"))
        finally:
            os.makedirs = real_makedirs

    def test_remove_race_handling(self):
        """
        File storage should be robust against file removal race conditions.
        """
        real_remove = os.remove

        # Monkey-patch os.remove, to simulate a normal call, a raced call,
        # and an error.
        def fake_remove(path):
            if path == os.path.join(self.temp_dir, "normal.file"):
                real_remove(path)
            elif path == os.path.join(self.temp_dir, "raced.file"):
                real_remove(path)
                raise FileNotFoundError()
            elif path == os.path.join(self.temp_dir, "error.file"):
                raise PermissionError()
            else:
                self.fail("unexpected argument %r" % path)

        try:
            os.remove = fake_remove

            self.storage.save("normal.file", ContentFile("delete normally"))
            self.storage.delete("normal.file")
            self.assertFalse(self.storage.exists("normal.file"))

            self.storage.save("raced.file", ContentFile("delete with race"))
            self.storage.delete("raced.file")
            self.assertFalse(self.storage.exists("normal.file"))

            # Exceptions aside from FileNotFoundError are raised.
            self.storage.save("error.file", ContentFile("delete with error"))
            with self.assertRaises(PermissionError):
                self.storage.delete("error.file")
        finally:
            os.remove = real_remove

    def test_file_chunks_error(self):
        """
        Test behavior when file.chunks() is raising an error
        """
        f1 = ContentFile("chunks fails")

        def failing_chunks():
            raise OSError

        f1.chunks = failing_chunks
        with self.assertRaises(OSError):
            self.storage.save("error.file", f1)

    def test_delete_no_name(self):
        """
        Calling delete with an empty name should not try to remove the base
        storage directory, but fail loudly (#20660).
        """
        msg = "The name must be given to delete()."
        with self.assertRaisesMessage(ValueError, msg):
            self.storage.delete(None)
        with self.assertRaisesMessage(ValueError, msg):
            self.storage.delete("")

    def test_delete_deletes_directories(self):
        tmp_dir = tempfile.mkdtemp(dir=self.storage.location)
        self.storage.delete(tmp_dir)
        self.assertFalse(os.path.exists(tmp_dir))

    @override_settings(
        MEDIA_ROOT="media_root",
        MEDIA_URL="media_url/",
        FILE_UPLOAD_PERMISSIONS=0o777,
        FILE_UPLOAD_DIRECTORY_PERMISSIONS=0o777,
    )
    def test_setting_changed(self):
        """
        Properties using settings values as defaults should be updated on
        referenced settings change while specified values should be unchanged.
        """
        storage = self.storage_class(
            location="explicit_location",
            base_url="explicit_base_url/",
            file_permissions_mode=0o666,
            directory_permissions_mode=0o666,
        )
        defaults_storage = self.storage_class()
        settings = {
            "MEDIA_ROOT": "overridden_media_root",
            "MEDIA_URL": "/overridden_media_url/",
            "FILE_UPLOAD_PERMISSIONS": 0o333,
            "FILE_UPLOAD_DIRECTORY_PERMISSIONS": 0o333,
        }
        with self.settings(**settings):
            self.assertEqual(storage.base_location, "explicit_location")
            self.assertIn("explicit_location", storage.location)
            self.assertEqual(storage.base_url, "explicit_base_url/")
            self.assertEqual(storage.file_permissions_mode, 0o666)
            self.assertEqual(storage.directory_permissions_mode, 0o666)
            self.assertEqual(defaults_storage.base_location, settings["MEDIA_ROOT"])
            self.assertIn(settings["MEDIA_ROOT"], defaults_storage.location)
            self.assertEqual(defaults_storage.base_url, settings["MEDIA_URL"])
            self.assertEqual(
                defaults_storage.file_permissions_mode,
                settings["FILE_UPLOAD_PERMISSIONS"],
            )
            self.assertEqual(
                defaults_storage.directory_permissions_mode,
                settings["FILE_UPLOAD_DIRECTORY_PERMISSIONS"],
            )

    def test_file_methods_pathlib_path(self):
        p = Path("test.file")
        self.assertFalse(self.storage.exists(p))
        f = ContentFile("custom contents")
        f_name = self.storage.save(p, f)
        # Storage basic methods.
        self.assertEqual(self.storage.path(p), os.path.join(self.temp_dir, p))
        self.assertEqual(self.storage.size(p), 15)
        self.assertEqual(self.storage.url(p), self.storage.base_url + f_name)
        with self.storage.open(p) as f:
            self.assertEqual(f.read(), b"custom contents")
        self.addCleanup(self.storage.delete, p)


class CustomStorage(FileSystemStorage):
    def get_available_name(self, name, max_length=None):
        """
        Append numbers to duplicate files rather than underscores, like Trac.
        """
        basename, *ext = os.path.splitext(name)
        number = 2
        while self.exists(name):
            name = "".join([basename, ".", str(number)] + ext)
            number += 1

        return name


class CustomStorageTests(FileStorageTests):
    storage_class = CustomStorage

    def test_custom_get_available_name(self):
        first = self.storage.save("custom_storage", ContentFile("custom contents"))
        self.assertEqual(first, "custom_storage")
        second = self.storage.save("custom_storage", ContentFile("more contents"))
        self.assertEqual(second, "custom_storage.2")
        self.storage.delete(first)
        self.storage.delete(second)


# RemovedInDjango60Warning: Remove this class.
class OverwritingStorage(FileSystemStorage):
    """
    Overwrite existing files instead of appending a suffix to generate an
    unused name.
    """

    # Mask out O_EXCL so os.open() doesn't raise OSError if the file exists.
    OS_OPEN_FLAGS = FileSystemStorage.OS_OPEN_FLAGS & ~os.O_EXCL

    def get_available_name(self, name, max_length=None):
        """Override the effort to find an used name."""
        return name


# RemovedInDjango60Warning: Remove this test class.
class OverwritingStorageOSOpenFlagsWarningTests(SimpleTestCase):
    storage_class = OverwritingStorage

    def setUp(self):
        self.temp_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.temp_dir)

    def test_os_open_flags_deprecation_warning(self):
        msg = "Overriding OS_OPEN_FLAGS is deprecated. Use the allow_overwrite "
        msg += "parameter instead."
        with self.assertWarnsMessage(RemovedInDjango60Warning, msg):
            self.storage = self.storage_class(
                location=self.temp_dir, base_url="/test_media_url/"
            )


# RemovedInDjango60Warning: Remove this test class.
@ignore_warnings(category=RemovedInDjango60Warning)
class OverwritingStorageOSOpenFlagsTests(FileStorageTests):
    storage_class = OverwritingStorage

    def test_save_overwrite_behavior(self):
        """Saving to same file name twice overwrites the first file."""
        name = "test.file"
        self.assertFalse(self.storage.exists(name))
        content_1 = b"content one"
        content_2 = b"second content"
        f_1 = ContentFile(content_1)
        f_2 = ContentFile(content_2)
        stored_name_1 = self.storage.save(name, f_1)
        try:
            self.assertEqual(stored_name_1, name)
            self.assertTrue(self.storage.exists(name))
            self.assertTrue(os.path.exists(os.path.join(self.temp_dir, name)))
            with self.storage.open(name) as fp:
                self.assertEqual(fp.read(), content_1)
            stored_name_2 = self.storage.save(name, f_2)
            self.assertEqual(stored_name_2, name)
            self.assertTrue(self.storage.exists(name))
            self.assertTrue(os.path.exists(os.path.join(self.temp_dir, name)))
            with self.storage.open(name) as fp:
                self.assertEqual(fp.read(), content_2)
        finally:
            self.storage.delete(name)


class OverwritingStorageTests(FileStorageTests):
    storage_class = FileSystemStorage

    def setUp(self):
        self.temp_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.temp_dir)
        self.storage = self.storage_class(
            location=self.temp_dir, base_url="/test_media_url/", allow_overwrite=True
        )

    def test_save_overwrite_behavior(self):
        """Saving to same file name twice overwrites the first file."""
        name = "test.file"
        self.assertFalse(self.storage.exists(name))
        content_1 = b"content one"
        content_2 = b"second content"
        f_1 = ContentFile(content_1)
        f_2 = ContentFile(content_2)
        stored_name_1 = self.storage.save(name, f_1)
        try:
            self.assertEqual(stored_name_1, name)
            self.assertTrue(self.storage.exists(name))
            with self.storage.open(name) as fp:
                self.assertEqual(fp.read(), content_1)
            stored_name_2 = self.storage.save(name, f_2)
            self.assertEqual(stored_name_2, name)
            self.assertTrue(self.storage.exists(name))
            with self.storage.open(name) as fp:
                self.assertEqual(fp.read(), content_2)
        finally:
            self.storage.delete(name)

    def test_save_overwrite_behavior_temp_file(self):
        """Saving to same file name twice overwrites the first file."""
        name = "test.file"
        self.assertFalse(self.storage.exists(name))
        content_1 = b"content one"
        content_2 = b"second content"
        f_1 = TemporaryUploadedFile("tmp1", "text/plain", 11, "utf8")
        f_1.write(content_1)
        f_1.seek(0)
        f_2 = TemporaryUploadedFile("tmp2", "text/plain", 14, "utf8")
        f_2.write(content_2)
        f_2.seek(0)
        stored_name_1 = self.storage.save(name, f_1)
        try:
            self.assertEqual(stored_name_1, name)
            self.assertTrue(os.path.exists(os.path.join(self.temp_dir, name)))
            with self.storage.open(name) as fp:
                self.assertEqual(fp.read(), content_1)
            stored_name_2 = self.storage.save(name, f_2)
            self.assertEqual(stored_name_2, name)
            self.assertTrue(os.path.exists(os.path.join(self.temp_dir, name)))
            with self.storage.open(name) as fp:
                self.assertEqual(fp.read(), content_2)
        finally:
            self.storage.delete(name)

    def test_file_name_truncation(self):
        name = "test_long_file_name.txt"
        file = ContentFile(b"content")
        stored_name = self.storage.save(name, file, max_length=10)
        self.addCleanup(self.storage.delete, stored_name)
        self.assertEqual(stored_name, "test_l.txt")
        self.assertEqual(len(stored_name), 10)

    def test_file_name_truncation_extension_too_long(self):
        name = "file_name.longext"
        file = ContentFile(b"content")
        with self.assertRaisesMessage(
            SuspiciousFileOperation, "Storage can not find an available filename"
        ):
            self.storage.save(name, file, max_length=5)


class DiscardingFalseContentStorage(FileSystemStorage):
    def _save(self, name, content):
        if content:
            return super()._save(name, content)
        return ""


class DiscardingFalseContentStorageTests(FileStorageTests):
    storage_class = DiscardingFalseContentStorage

    def test_custom_storage_discarding_empty_content(self):
        """
        When Storage.save() wraps a file-like object in File, it should include
        the name argument so that bool(file) evaluates to True (#26495).
        """
        output = StringIO("content")
        self.storage.save("tests/stringio", output)
        self.assertTrue(self.storage.exists("tests/stringio"))

        with self.storage.open("tests/stringio") as f:
            self.assertEqual(f.read(), b"content")


class FileFieldStorageTests(TestCase):
    def tearDown(self):
        shutil.rmtree(temp_storage_location)

    def _storage_max_filename_length(self, storage):
        """
        Query filesystem for maximum filename length (e.g. AUFS has 242).
        """
        dir_to_test = storage.location
        while not os.path.exists(dir_to_test):
            dir_to_test = os.path.dirname(dir_to_test)
        try:
            return os.pathconf(dir_to_test, "PC_NAME_MAX")
        except Exception:
            return 255  # Should be safe on most backends

    def test_files(self):
        self.assertIsInstance(Storage.normal, FileDescriptor)

        # An object without a file has limited functionality.
        obj1 = Storage()
        self.assertEqual(obj1.normal.name, "")
        with self.assertRaises(ValueError):
            obj1.normal.size

        # Saving a file enables full functionality.
        obj1.normal.save("django_test.txt", ContentFile("content"))
        self.assertEqual(obj1.normal.name, "tests/django_test.txt")
        self.assertEqual(obj1.normal.size, 7)
        self.assertEqual(obj1.normal.read(), b"content")
        obj1.normal.close()

        # File objects can be assigned to FileField attributes, but shouldn't
        # get committed until the model it's attached to is saved.
        obj1.normal = SimpleUploadedFile("assignment.txt", b"content")
        dirs, files = temp_storage.listdir("tests")
        self.assertEqual(dirs, [])
        self.assertNotIn("assignment.txt", files)

        obj1.save()
        dirs, files = temp_storage.listdir("tests")
        self.assertEqual(sorted(files), ["assignment.txt", "django_test.txt"])

        # Save another file with the same name.
        obj2 = Storage()
        obj2.normal.save("django_test.txt", ContentFile("more content"))
        obj2_name = obj2.normal.name
        self.assertRegex(obj2_name, "tests/django_test_%s.txt" % FILE_SUFFIX_REGEX)
        self.assertEqual(obj2.normal.size, 12)
        obj2.normal.close()

        # Deleting an object does not delete the file it uses.
        obj2.delete()
        obj2.normal.save("django_test.txt", ContentFile("more content"))
        self.assertNotEqual(obj2_name, obj2.normal.name)
        self.assertRegex(
            obj2.normal.name, "tests/django_test_%s.txt" % FILE_SUFFIX_REGEX
        )
        obj2.normal.close()

    def test_filefield_read(self):
        # Files can be read in a little at a time, if necessary.
        obj = Storage.objects.create(
            normal=SimpleUploadedFile("assignment.txt", b"content")
        )
        obj.normal.open()
        self.assertEqual(obj.normal.read(3), b"con")
        self.assertEqual(obj.normal.read(), b"tent")
        self.assertEqual(
            list(obj.normal.chunks(chunk_size=2)), [b"co", b"nt", b"en", b"t"]
        )
        obj.normal.close()

    def test_filefield_write(self):
        # Files can be written to.
        obj = Storage.objects.create(
            normal=SimpleUploadedFile("rewritten.txt", b"content")
        )
        with obj.normal as normal:
            normal.open("wb")
            normal.write(b"updated")
        obj.refresh_from_db()
        self.assertEqual(obj.normal.read(), b"updated")
        obj.normal.close()

    def test_filefield_reopen(self):
        obj = Storage.objects.create(
            normal=SimpleUploadedFile("reopen.txt", b"content")
        )
        with obj.normal as normal:
            normal.open()
        obj.normal.open()
        obj.normal.file.seek(0)
        obj.normal.close()

    def test_duplicate_filename(self):
        # Multiple files with the same name get _(7 random chars) appended to them.
        tests = [
            ("multiple_files", "txt"),
            ("multiple_files_many_extensions", "tar.gz"),
        ]
        for filename, extension in tests:
            with self.subTest(filename=filename):
                objs = [Storage() for i in range(2)]
                for o in objs:
                    o.normal.save(f"{filename}.{extension}", ContentFile("Content"))
                try:
                    names = [o.normal.name for o in objs]
                    self.assertEqual(names[0], f"tests/{filename}.{extension}")
                    self.assertRegex(
                        names[1], f"tests/{filename}_{FILE_SUFFIX_REGEX}.{extension}"
                    )
                finally:
                    for o in objs:
                        o.delete()

    def test_file_truncation(self):
        # Given the max_length is limited, when multiple files get uploaded
        # under the same name, then the filename get truncated in order to fit
        # in _(7 random chars). When most of the max_length is taken by
        # dirname + extension and there are not enough  characters in the
        # filename to truncate, an exception should be raised.
        objs = [Storage() for i in range(2)]
        filename = "filename.ext"

        for o in objs:
            o.limited_length.save(filename, ContentFile("Same Content"))
        try:
            # Testing truncation.
            names = [o.limited_length.name for o in objs]
            self.assertEqual(names[0], "tests/%s" % filename)
            self.assertRegex(names[1], "tests/fi_%s.ext" % FILE_SUFFIX_REGEX)

            # Testing exception is raised when filename is too short to truncate.
            filename = "short.longext"
            objs[0].limited_length.save(filename, ContentFile("Same Content"))
            with self.assertRaisesMessage(
                SuspiciousFileOperation, "Storage can not find an available filename"
            ):
                objs[1].limited_length.save(*(filename, ContentFile("Same Content")))
        finally:
            for o in objs:
                o.delete()

    @unittest.skipIf(
        sys.platform == "win32",
        "Windows supports at most 260 characters in a path.",
    )
    def test_extended_length_storage(self):
        # Testing FileField with max_length > 255. Most systems have filename
        # length limitation of 255. Path takes extra chars.
        filename = (
            self._storage_max_filename_length(temp_storage) - 4
        ) * "a"  # 4 chars for extension.
        obj = Storage()
        obj.extended_length.save("%s.txt" % filename, ContentFile("Same Content"))
        self.assertEqual(obj.extended_length.name, "tests/%s.txt" % filename)
        self.assertEqual(obj.extended_length.read(), b"Same Content")
        obj.extended_length.close()

    def test_filefield_default(self):
        # Default values allow an object to access a single file.
        temp_storage.save("tests/default.txt", ContentFile("default content"))
        obj = Storage.objects.create()
        self.assertEqual(obj.default.name, "tests/default.txt")
        self.assertEqual(obj.default.read(), b"default content")
        obj.default.close()

        # But it shouldn't be deleted, even if there are no more objects using
        # it.
        obj.delete()
        obj = Storage()
        self.assertEqual(obj.default.read(), b"default content")
        obj.default.close()

    def test_empty_upload_to(self):
        # upload_to can be empty, meaning it does not use subdirectory.
        obj = Storage()
        obj.empty.save("django_test.txt", ContentFile("more content"))
        self.assertEqual(obj.empty.name, "django_test.txt")
        self.assertEqual(obj.empty.read(), b"more content")
        obj.empty.close()

    def test_pathlib_upload_to(self):
        obj = Storage()
        obj.pathlib_callable.save("some_file1.txt", ContentFile("some content"))
        self.assertEqual(obj.pathlib_callable.name, "bar/some_file1.txt")
        obj.pathlib_direct.save("some_file2.txt", ContentFile("some content"))
        self.assertEqual(obj.pathlib_direct.name, "bar/some_file2.txt")
        obj.random.close()

    def test_random_upload_to(self):
        # Verify the fix for #5655, making sure the directory is only
        # determined once.
        obj = Storage()
        obj.random.save("random_file", ContentFile("random content"))
        self.assertTrue(obj.random.name.endswith("/random_file"))
        obj.random.close()

    def test_custom_valid_name_callable_upload_to(self):
        """
        Storage.get_valid_name() should be called when upload_to is a callable.
        """
        obj = Storage()
        obj.custom_valid_name.save("random_file", ContentFile("random content"))
        # CustomValidNameStorage.get_valid_name() appends '_valid' to the name
        self.assertTrue(obj.custom_valid_name.name.endswith("/random_file_valid"))
        obj.custom_valid_name.close()

    def test_filefield_pickling(self):
        # Push an object into the cache to make sure it pickles properly
        obj = Storage()
        obj.normal.save("django_test.txt", ContentFile("more content"))
        obj.normal.close()
        cache.set("obj", obj)
        self.assertEqual(cache.get("obj").normal.name, "tests/django_test.txt")

    def test_file_object(self):
        # Create sample file
        temp_storage.save("tests/example.txt", ContentFile("some content"))

        # Load it as Python file object
        with open(temp_storage.path("tests/example.txt")) as file_obj:
            # Save it using storage and read its content
            temp_storage.save("tests/file_obj", file_obj)
        self.assertTrue(temp_storage.exists("tests/file_obj"))
        with temp_storage.open("tests/file_obj") as f:
            self.assertEqual(f.read(), b"some content")

    def test_stringio(self):
        # Test passing StringIO instance as content argument to save
        output = StringIO()
        output.write("content")
        output.seek(0)

        # Save it and read written file
        temp_storage.save("tests/stringio", output)
        self.assertTrue(temp_storage.exists("tests/stringio"))
        with temp_storage.open("tests/stringio") as f:
            self.assertEqual(f.read(), b"content")


class FieldCallableFileStorageTests(SimpleTestCase):
    def setUp(self):
        self.temp_storage_location = tempfile.mkdtemp(
            suffix="filefield_callable_storage"
        )
        self.addCleanup(shutil.rmtree, self.temp_storage_location)

    def test_callable_base_class_error_raises(self):
        class NotStorage:
            pass

        msg = (
            "FileField.storage must be a subclass/instance of "
            "django.core.files.storage.base.Storage"
        )
        for invalid_type in (NotStorage, str, list, set, tuple):
            with self.subTest(invalid_type=invalid_type):
                with self.assertRaisesMessage(TypeError, msg):
                    FileField(storage=invalid_type)

    def test_file_field_storage_none_uses_default_storage(self):
        self.assertEqual(FileField().storage, default_storage)

    def test_callable_function_storage_file_field(self):
        storage = FileSystemStorage(location=self.temp_storage_location)

        def get_storage():
            return storage

        obj = FileField(storage=get_storage)
        self.assertEqual(obj.storage, storage)
        self.assertEqual(obj.storage.location, storage.location)

    def test_callable_class_storage_file_field(self):
        class GetStorage(FileSystemStorage):
            pass

        obj = FileField(storage=GetStorage)
        self.assertIsInstance(obj.storage, BaseStorage)

    def test_callable_storage_file_field_in_model(self):
        obj = Storage()
        self.assertEqual(obj.storage_callable.storage, temp_storage)
        self.assertEqual(obj.storage_callable.storage.location, temp_storage_location)
        self.assertIsInstance(obj.storage_callable_class.storage, BaseStorage)

    def test_deconstruction(self):
        """
        Deconstructing gives the original callable, not the evaluated value.
        """
        obj = Storage()
        *_, kwargs = obj._meta.get_field("storage_callable").deconstruct()
        storage = kwargs["storage"]
        self.assertIs(storage, callable_storage)

    def test_deconstruction_storage_callable_default(self):
        """
        A callable that returns default_storage is not omitted when
        deconstructing.
        """
        obj = Storage()
        *_, kwargs = obj._meta.get_field("storage_callable_default").deconstruct()
        self.assertIs(kwargs["storage"], callable_default_storage)


# Tests for a race condition on file saving (#4948).
# This is written in such a way that it'll always pass on platforms
# without threading.


class SlowFile(ContentFile):
    def chunks(self):
        time.sleep(1)
        return super().chunks()


class FileSaveRaceConditionTest(SimpleTestCase):
    def setUp(self):
        self.storage_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.storage_dir)
        self.storage = FileSystemStorage(self.storage_dir)
        self.thread = threading.Thread(target=self.save_file, args=["conflict"])

    def save_file(self, name):
        name = self.storage.save(name, SlowFile(b"Data"))

    def test_race_condition(self):
        self.thread.start()
        self.save_file("conflict")
        self.thread.join()
        files = sorted(os.listdir(self.storage_dir))
        self.assertEqual(files[0], "conflict")
        self.assertRegex(files[1], "conflict_%s" % FILE_SUFFIX_REGEX)


@unittest.skipIf(
    sys.platform == "win32", "Windows only partially supports umasks and chmod."
)
class FileStoragePermissions(unittest.TestCase):
    def setUp(self):
        self.umask = 0o027
        old_umask = os.umask(self.umask)
        self.addCleanup(os.umask, old_umask)
        self.storage_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.storage_dir)

    @override_settings(FILE_UPLOAD_PERMISSIONS=0o654)
    def test_file_upload_permissions(self):
        self.storage = FileSystemStorage(self.storage_dir)
        name = self.storage.save("the_file", ContentFile("data"))
        actual_mode = os.stat(self.storage.path(name))[0] & 0o777
        self.assertEqual(actual_mode, 0o654)

    @override_settings(FILE_UPLOAD_PERMISSIONS=None)
    def test_file_upload_default_permissions(self):
        self.storage = FileSystemStorage(self.storage_dir)
        fname = self.storage.save("some_file", ContentFile("data"))
        mode = os.stat(self.storage.path(fname))[0] & 0o777
        self.assertEqual(mode, 0o666 & ~self.umask)

    @override_settings(FILE_UPLOAD_DIRECTORY_PERMISSIONS=0o765)
    def test_file_upload_directory_permissions(self):
        self.storage = FileSystemStorage(self.storage_dir)
        name = self.storage.save("the_directory/subdir/the_file", ContentFile("data"))
        file_path = Path(self.storage.path(name))
        self.assertEqual(file_path.parent.stat().st_mode & 0o777, 0o765)
        self.assertEqual(file_path.parent.parent.stat().st_mode & 0o777, 0o765)

    @override_settings(FILE_UPLOAD_DIRECTORY_PERMISSIONS=None)
    def test_file_upload_directory_default_permissions(self):
        self.storage = FileSystemStorage(self.storage_dir)
        name = self.storage.save("the_directory/subdir/the_file", ContentFile("data"))
        file_path = Path(self.storage.path(name))
        expected_mode = 0o777 & ~self.umask
        self.assertEqual(file_path.parent.stat().st_mode & 0o777, expected_mode)
        self.assertEqual(file_path.parent.parent.stat().st_mode & 0o777, expected_mode)


class FileStoragePathParsing(SimpleTestCase):
    def setUp(self):
        self.storage_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.storage_dir)
        self.storage = FileSystemStorage(self.storage_dir)

    def test_directory_with_dot(self):
        """Regression test for #9610.

        If the directory name contains a dot and the file name doesn't, make
        sure we still mangle the file name instead of the directory name.
        """

        self.storage.save("dotted.path/test", ContentFile("1"))
        self.storage.save("dotted.path/test", ContentFile("2"))

        files = sorted(os.listdir(os.path.join(self.storage_dir, "dotted.path")))
        self.assertFalse(os.path.exists(os.path.join(self.storage_dir, "dotted_.path")))
        self.assertEqual(files[0], "test")
        self.assertRegex(files[1], "test_%s" % FILE_SUFFIX_REGEX)

    def test_first_character_dot(self):
        """
        File names with a dot as their first character don't have an extension,
        and the underscore should get added to the end.
        """
        self.storage.save("dotted.path/.test", ContentFile("1"))
        self.storage.save("dotted.path/.test", ContentFile("2"))

        files = sorted(os.listdir(os.path.join(self.storage_dir, "dotted.path")))
        self.assertFalse(os.path.exists(os.path.join(self.storage_dir, "dotted_.path")))
        self.assertEqual(files[0], ".test")
        self.assertRegex(files[1], ".test_%s" % FILE_SUFFIX_REGEX)


class ContentFileStorageTestCase(unittest.TestCase):
    def setUp(self):
        storage_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, storage_dir)
        self.storage = FileSystemStorage(storage_dir)

    def test_content_saving(self):
        """
        ContentFile can be saved correctly with the filesystem storage,
        if it was initialized with either bytes or unicode content.
        """
        self.storage.save("bytes.txt", ContentFile(b"content"))
        self.storage.save("unicode.txt", ContentFile("español"))


@override_settings(ROOT_URLCONF="file_storage.urls")
class FileLikeObjectTestCase(LiveServerTestCase):
    """
    Test file-like objects (#15644).
    """

    available_apps = []

    def setUp(self):
        self.temp_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.temp_dir)
        self.storage = FileSystemStorage(location=self.temp_dir)

    def test_urllib_request_urlopen(self):
        """
        Test the File storage API with a file-like object coming from
        urllib.request.urlopen().
        """
        file_like_object = urlopen(self.live_server_url + "/")
        f = File(file_like_object)
        stored_filename = self.storage.save("remote_file.html", f)

        remote_file = urlopen(self.live_server_url + "/")
        with self.storage.open(stored_filename) as stored_file:
            self.assertEqual(stored_file.read(), remote_file.read())


class StorageHandlerTests(SimpleTestCase):
    @override_settings(
        STORAGES={
            "custom_storage": {
                "BACKEND": "django.core.files.storage.FileSystemStorage",
            },
        }
    )
    def test_same_instance(self):
        cache1 = storages["custom_storage"]
        cache2 = storages["custom_storage"]
        self.assertIs(cache1, cache2)

    def test_defaults(self):
        storages = StorageHandler()
        self.assertEqual(
            storages.backends,
            {
                DEFAULT_STORAGE_ALIAS: {
                    "BACKEND": "django.core.files.storage.FileSystemStorage",
                },
                STATICFILES_STORAGE_ALIAS: {
                    "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage",
                },
            },
        )

    def test_nonexistent_alias(self):
        msg = "Could not find config for 'nonexistent' in settings.STORAGES."
        storages = StorageHandler()
        with self.assertRaisesMessage(InvalidStorageError, msg):
            storages["nonexistent"]

    def test_nonexistent_backend(self):
        test_storages = StorageHandler(
            {
                "invalid_backend": {
                    "BACKEND": "django.nonexistent.NonexistentBackend",
                },
            }
        )
        msg = (
            "Could not find backend 'django.nonexistent.NonexistentBackend': "
            "No module named 'django.nonexistent'"
        )
        with self.assertRaisesMessage(InvalidStorageError, msg):
            test_storages["invalid_backend"]