text: from __future__ import absolute_import
  
  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)
  