django/tests/modeltests/files/tests.py

from __future__ import with_statement

import shutil
import tempfile

from django.core.cache import cache
from django.core.files import File
from django.core.files.base import ContentFile
from django.core.files.uploadedfile import SimpleUploadedFile
from django.test import TestCase

from models import Storage, temp_storage, temp_storage_location


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

    def test_files(self):
        temp_storage.save('tests/default.txt', ContentFile('default content'))
        # Attempting to access a FileField from the class raises a descriptive
        # error
        self.assertRaises(AttributeError, lambda: Storage.normal)

        # An object without a file has limited functionality.
        obj1 = Storage()
        self.assertEqual(obj1.normal.name, "")
        self.assertRaises(ValueError, lambda: 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(), "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", "content")
        dirs, files = temp_storage.listdir("tests")
        self.assertEqual(dirs, [])
        self.assertEqual(sorted(files), ["default.txt", "django_test.txt"])

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

        # Files can be read in a little at a time, if necessary.
        obj1.normal.open()
        self.assertEqual(obj1.normal.read(3), "con")
        self.assertEqual(obj1.normal.read(), "tent")
        self.assertEqual(list(obj1.normal.chunks(chunk_size=2)), ["co", "nt", "en", "t"])
        obj1.normal.close()

        # Save another file with the same name.
        obj2 = Storage()
        obj2.normal.save("django_test.txt", ContentFile("more content"))
        self.assertEqual(obj2.normal.name, "tests/django_test_1.txt")
        self.assertEqual(obj2.normal.size, 12)

        # Push the objects into the cache to make sure they pickle properly
        cache.set("obj1", obj1)
        cache.set("obj2", obj2)
        self.assertEqual(cache.get("obj2").normal.name, "tests/django_test_1.txt")

        # Deleting an object does not delete the file it uses.
        obj2.delete()
        obj2.normal.save("django_test.txt", ContentFile("more content"))
        self.assertEqual(obj2.normal.name, "tests/django_test_2.txt")

        # Multiple files with the same name get _N appended to them.
        objs = [Storage() for i in range(3)]
        for o in objs:
            o.normal.save("multiple_files.txt", ContentFile("Same Content"))
        self.assertEqual(
            [o.normal.name for o in objs],
            ["tests/multiple_files.txt", "tests/multiple_files_1.txt", "tests/multiple_files_2.txt"]
        )
        for o in objs:
            o.delete()

        # Default values allow an object to access a single file.
        obj3 = Storage.objects.create()
        self.assertEqual(obj3.default.name, "tests/default.txt")
        self.assertEqual(obj3.default.read(), "default content")
        obj3.default.close()

        # But it shouldn't be deleted, even if there are no more objects using
        # it.
        obj3.delete()
        obj3 = Storage()
        self.assertEqual(obj3.default.read(), "default content")
        obj3.default.close()

        # Verify the fix for #5655, making sure the directory is only
        # determined once.
        obj4 = Storage()
        obj4.random.save("random_file", ContentFile("random content"))
        self.assertTrue(obj4.random.name.endswith("/random_file"))

        # Clean up the temporary files and dir.
        obj1.normal.delete()
        obj2.normal.delete()
        obj3.default.delete()
        obj4.random.delete()

    def test_context_manager(self):
        orig_file = tempfile.TemporaryFile()
        base_file = File(orig_file)
        with base_file as f:
            self.assertIs(base_file, f)
            self.assertFalse(f.closed)
        self.assertTrue(f.closed)
        self.assertTrue(orig_file.closed)