fix & test a migration

src/documents/migrations/1003_mime_types.py

@@ -11,6 +11,7 @@ from paperless.db import GnuPG
 STORAGE_TYPE_UNENCRYPTED = "unencrypted"
 STORAGE_TYPE_GPG = "gpg"
 
+
 def source_path(self):
     if self.filename:
         fname = str(self.filename)

src/documents/tests/test_migrations.py

@@ -0,0 +1,129 @@
+import os
+import shutil
+from pathlib import Path
+
+from django.apps import apps
+from django.conf import settings
+from django.db import connection
+from django.db.migrations.executor import MigrationExecutor
+from django.test import TestCase, TransactionTestCase, override_settings
+
+from documents.models import Document
+from documents.parsers import get_default_file_extension
+from documents.tests.utils import DirectoriesMixin
+
+
+class TestMigrations(TransactionTestCase):
+
+    @property
+    def app(self):
+        return apps.get_containing_app_config(type(self).__module__).name
+
+    migrate_from = None
+    migrate_to = None
+
+    def setUp(self):
+        super(TestMigrations, self).setUp()
+
+        assert self.migrate_from and self.migrate_to, \
+            "TestCase '{}' must define migrate_from and migrate_to     properties".format(type(self).__name__)
+        self.migrate_from = [(self.app, self.migrate_from)]
+        self.migrate_to = [(self.app, self.migrate_to)]
+        executor = MigrationExecutor(connection)
+        old_apps = executor.loader.project_state(self.migrate_from).apps
+
+        # Reverse to the original migration
+        executor.migrate(self.migrate_from)
+
+        self.setUpBeforeMigration(old_apps)
+
+        # Run the migration to test
+        executor = MigrationExecutor(connection)
+        executor.loader.build_graph()  # reload.
+        executor.migrate(self.migrate_to)
+
+        self.apps = executor.loader.project_state(self.migrate_to).apps
+
+    def setUpBeforeMigration(self, apps):
+        pass
+
+
+STORAGE_TYPE_UNENCRYPTED = "unencrypted"
+STORAGE_TYPE_GPG = "gpg"
+
+
+def source_path_before(self):
+    if self.filename:
+        fname = str(self.filename)
+    else:
+        fname = "{:07}.{}".format(self.pk, self.file_type)
+        if self.storage_type == STORAGE_TYPE_GPG:
+            fname += ".gpg"
+
+    return os.path.join(
+        settings.ORIGINALS_DIR,
+        fname
+    )
+
+
+def file_type_after(self):
+    return get_default_file_extension(self.mime_type)
+
+
+def source_path_after(doc):
+    if doc.filename:
+        fname = str(doc.filename)
+    else:
+        fname = "{:07}{}".format(doc.pk, file_type_after(doc))
+        if doc.storage_type == STORAGE_TYPE_GPG:
+            fname += ".gpg"  # pragma: no cover
+
+    return os.path.join(
+        settings.ORIGINALS_DIR,
+        fname
+    )
+
+
+@override_settings(PASSPHRASE="test")
+class TestMigrateMimeType(DirectoriesMixin, TestMigrations):
+
+    migrate_from = '1002_auto_20201111_1105'
+    migrate_to = '1003_mime_types'
+
+    def setUpBeforeMigration(self, apps):
+        Document = apps.get_model("documents", "Document")
+        doc = Document.objects.create(title="test", file_type="pdf", filename="file1.pdf")
+        self.doc_id = doc.id
+        shutil.copy(os.path.join(os.path.dirname(__file__), "samples", "simple.pdf"), source_path_before(doc))
+
+        doc2 = Document.objects.create(checksum="B", file_type="pdf", storage_type=STORAGE_TYPE_GPG)
+        self.doc2_id = doc2.id
+        shutil.copy(os.path.join(os.path.dirname(__file__), "samples", "documents", "originals", "0000002.pdf.gpg"), source_path_before(doc2))
+
+    def testMimeTypesMigrated(self):
+        Document = self.apps.get_model('documents', 'Document')
+
+        doc = Document.objects.get(id=self.doc_id)
+        self.assertEqual(doc.mime_type, "application/pdf")
+
+        doc2 = Document.objects.get(id=self.doc2_id)
+        self.assertEqual(doc2.mime_type, "application/pdf")
+
+
+@override_settings(PASSPHRASE="test")
+class TestMigrateMimeTypeBackwards(DirectoriesMixin, TestMigrations):
+
+    migrate_from = '1003_mime_types'
+    migrate_to = '1002_auto_20201111_1105'
+
+    def setUpBeforeMigration(self, apps):
+        Document = apps.get_model("documents", "Document")
+        doc = Document.objects.create(title="test", mime_type="application/pdf", filename="file1.pdf")
+        self.doc_id = doc.id
+        shutil.copy(os.path.join(os.path.dirname(__file__), "samples", "simple.pdf"), source_path_after(doc))
+
+    def testMimeTypesReverted(self):
+        Document = self.apps.get_model('documents', 'Document')
+
+        doc = Document.objects.get(id=self.doc_id)
+        self.assertEqual(doc.file_type, "pdf")