Add tests to document how dirtyfields works with FileFields

tests/django_settings.py

@@ -1,5 +1,6 @@
 # Minimum settings that are needed to run django test suite
 import os
+import tempfile
 
 SECRET_KEY = 'WE DONT CARE ABOUT IT'
 
@@ -26,3 +27,5 @@
     }
 
 INSTALLED_APPS = ('tests', )
+
+MEDIA_ROOT = tempfile.mkdtemp(prefix="django-dirtyfields-test-media-root-")

tests/files/bar.txt

@@ -0,0 +1 @@
+bar-content

tests/files/foo.txt

@@ -0,0 +1 @@
+foo-content

tests/models.py

@@ -155,3 +155,7 @@ class ModelWithM2MAndSpecifiedFieldsTest(DirtyFieldsMixin, models.Model):
 
 class BinaryModelTest(DirtyFieldsMixin, models.Model):
     bytea = models.BinaryField()
+
+
+class FileFieldModel(DirtyFieldsMixin, models.Model):
+    file1 = models.FileField(upload_to="file1/")

tests/test_core.py

@@ -1,8 +1,14 @@
 from decimal import Decimal
+from os.path import dirname, join
+
 import pytest
+from django.core.files.base import ContentFile, File
 
-from .models import (ModelTest, ModelWithForeignKeyTest, ModelWithOneToOneFieldTest,
-                     SubclassModelTest, ModelWithDecimalFieldTest)
+from .models import (ModelTest, ModelWithForeignKeyTest,
+                     ModelWithOneToOneFieldTest,
+                     SubclassModelTest, ModelWithDecimalFieldTest,
+                     FileFieldModel)
+from .utils import FakeFieldFile
 
 
 @pytest.mark.django_db
@@ -199,3 +205,47 @@ def test_refresh_from_db_no_fields():
     assert tm.boolean is False
     assert tm.characters == "new value"
     assert tm.get_dirty_fields() == {"boolean": True, "characters": "old value"}
+
+
+@pytest.mark.django_db
+def test_file_fields_content_file():
+    tm = FileFieldModel()
+    # field is dirty because model is unsaved
+    assert tm.get_dirty_fields() == {"file1": FakeFieldFile("")}
+    tm.save()
+    assert tm.get_dirty_fields() == {}
+
+    # set file makes field dirty
+    tm.file1.save("test-file-1.txt", ContentFile(b"Test file content 1"), save=False)
+    assert tm.get_dirty_fields() == {"file1": FakeFieldFile("")}
+    tm.save()
+    assert tm.get_dirty_fields() == {}
+
+    # change file makes field dirty
+    tm.file1.save("test-file-2.txt", ContentFile(b"Test file content 2"), save=False)
+    assert tm.get_dirty_fields() == {"file1": FakeFieldFile("file1/test-file-1.txt")}
+    tm.save()
+    assert tm.get_dirty_fields() == {}
+
+
+@pytest.mark.django_db
+def test_file_fields_real_file():
+    tm = FileFieldModel()
+    # field is dirty because model is unsaved
+    assert tm.get_dirty_fields() == {"file1": FakeFieldFile("")}
+    tm.save()
+    assert tm.get_dirty_fields() == {}
+
+    # set file makes field dirty
+    with open(join(dirname(__file__), "files", "foo.txt"), "rb") as f:
+        tm.file1.save("test-file-3.txt", File(f), save=False)
+    assert tm.get_dirty_fields() == {"file1": FakeFieldFile("")}
+    tm.save()
+    assert tm.get_dirty_fields() == {}
+
+    # change file makes field dirty
+    with open(join(dirname(__file__), "files", "bar.txt"), "rb") as f:
+        tm.file1.save("test-file-4.txt", File(f), save=False)
+    assert tm.get_dirty_fields() == {"file1": FakeFieldFile("file1/test-file-3.txt")}
+    tm.save()
+    assert tm.get_dirty_fields() == {}

tests/utils.py

@@ -1,4 +1,5 @@
 import re
+from collections import namedtuple
 
 from django.conf import settings
 from django.db import connection
@@ -62,3 +63,7 @@ def is_postgresql_env_with_jsonb_field():
         PG_VERSION = 0
 
     return PG_VERSION >= 90400
+
+
+# Will compare equal with a django `FieldFile` instance in tests.
+FakeFieldFile = namedtuple("FakeFieldFile", ["name"])