Do some basic backend file verification during tests

Ideally we would use different parser here to test also for errors in
parser. This way we rely on ttkit doing the right thing and test just
Weblate interactions.

See issue #334

trans/tests/views.py

@@ -229,6 +229,37 @@ class EditTest(ViewTestCase):
         )
         self.translate_url = self.translation.get_translate_url()
 
+    def assertBackend(self, expected_translated):
+        '''
+        Checks that backend has correct data.
+        '''
+        translation = self.subproject.translation_set.get(
+            language_code='cs'
+        )
+        store = translation.subproject.file_format_cls(
+            translation.get_filename(),
+            None
+        )
+        messages = set()
+        translated = 0
+
+        for unit in store.all_units():
+            if not unit.is_translatable():
+                continue
+            checksum = unit.get_checksum()
+            self.assertFalse(
+                checksum in messages,
+                'Duplicate string in in backend file!'
+            )
+            if unit.is_translated():
+                translated += 1
+
+        self.assertEqual(
+            translated,
+            expected_translated,
+            'Did not found expected number of translations.'
+        )
+
     def test_edit(self):
         response = self.edit_unit(
             'Hello, world!\n',
@@ -241,6 +272,7 @@ class EditTest(ViewTestCase):
         self.assertEqual(len(unit.checks()), 0)
         self.assertTrue(unit.translated)
         self.assertFalse(unit.fuzzy)
+        self.assertBackend(1)
 
         # Test that second edit with no change does not break anything
         response = self.edit_unit(
@@ -254,6 +286,7 @@ class EditTest(ViewTestCase):
         self.assertEqual(len(unit.checks()), 0)
         self.assertTrue(unit.translated)
         self.assertFalse(unit.fuzzy)
+        self.assertBackend(1)
 
         # Test that third edit still works
         response = self.edit_unit(
@@ -267,6 +300,7 @@ class EditTest(ViewTestCase):
         self.assertEqual(len(unit.checks()), 0)
         self.assertTrue(unit.translated)
         self.assertFalse(unit.fuzzy)
+        self.assertBackend(1)
 
     def test_suggest(self):
         # Try empty suggestion (should not be added)
@@ -303,6 +337,7 @@ class EditTest(ViewTestCase):
         )
         # Check number of suggestions
         self.assertEqual(translation.have_suggestion, 1)
+        self.assertBackend(0)
 
         # Unit should not be translated
         self.assertEqual(len(unit.checks()), 0)
@@ -325,6 +360,7 @@ class EditTest(ViewTestCase):
         )
         # Check number of suggestions
         self.assertEqual(translation.have_suggestion, 1)
+        self.assertBackend(0)
 
         # Unit should not be translated
         self.assertEqual(len(unit.checks()), 0)
@@ -345,11 +381,12 @@ class EditTest(ViewTestCase):
         # Check number of suggestions
         self.assertEqual(translation.have_suggestion, 0)
 
-        # Unit should not be translated
+        # Unit should be translated
         self.assertEqual(len(unit.checks()), 0)
         self.assertTrue(unit.translated)
         self.assertFalse(unit.fuzzy)
         self.assertEqual(unit.target, 'Ahoj svete!\n')
+        self.assertBackend(1)
 
     def test_merge(self):
         # Translate unit to have something to start with
@@ -363,6 +400,7 @@ class EditTest(ViewTestCase):
             self.translate_url,
             {'checksum': unit.checksum, 'merge': unit.id}
         )
+        self.assertBackend(1)
         # We should get to second message
         self.assertRedirectsOffset(response, self.translate_url, 1)
 
@@ -415,6 +453,7 @@ class EditTest(ViewTestCase):
             {'checksum': unit.checksum, 'revert': change.id}
         )
         self.assertContains(response, "Can not revert to different unit")
+        self.assertBackend(1)
 
     def test_edit_fixup(self):
         # Save with failing check
@@ -430,6 +469,7 @@ class EditTest(ViewTestCase):
         self.assertEqual(len(unit.checks()), 0)
         self.assertEqual(len(unit.active_checks()), 0)
         self.assertEqual(unit.translation.failing_checks, 0)
+        self.assertBackend(1)
 
     def test_edit_check(self):
         # Save with failing check
@@ -471,6 +511,7 @@ class EditTest(ViewTestCase):
         self.assertFalse(unit.has_failing_check)
         self.assertEqual(len(unit.checks()), 0)
         self.assertEqual(unit.translation.failing_checks, 0)
+        self.assertBackend(1)
 
     def test_commit_push(self):
         response = self.edit_unit(
@@ -546,6 +587,7 @@ class EditTest(ViewTestCase):
         self.assertTrue(unit.fuzzy)
         self.assertEqual(unit.target, 'Nazdar svete!\n')
         self.assertFalse(unit.has_failing_check)
+        self.assertBackend(0)
 
 
 class EditResourceTest(EditTest):