Update Tests:

* don't use the project fixtures anymore but the one Django project
* update and refactor cache tests to be less brittle
* explicitly test mysql, postgresql and sqlite3 databases
* remove 'multiple_call' tests since it is not possible anymore
(with the Django singleton)
* update Travis and tox (dropping Python 3.4)

tests/functional/test_migration_linter.py

@@ -11,100 +11,97 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import os
 import unittest
 
+from django.conf import settings
+
 from django_migration_linter import MigrationLinter
 from tests import fixtures
 
 
 class BaseBackwardCompatibilityDetection(object):
-    def tearDown(self, *args, **kwargs):
-        fixtures.clear_all_git_projects()
-        super(
-            BaseBackwardCompatibilityDetection,
-            self).tearDown(*args, **kwargs)
+    def setUp(self, *args, **kwargs):
+        self.test_project_path = os.path.dirname(settings.BASE_DIR)
+        return super(BaseBackwardCompatibilityDetection, self).setUp(*args, **kwargs)
 
-    def _test_linter_finds_errors(self, path, commit_id=None):
-        linter = MigrationLinter(path, database=self.DATABASE, no_cache=True)
-        linter.lint_all_migrations(git_commit_id=commit_id)
+    def _test_linter_finds_errors(self, app=None, commit_id=None):
+        linter = self._launch_linter(app, commit_id)
         self.assertTrue(linter.has_errors)
+        self.assertNotEqual(linter.nb_valid + linter.nb_erroneous, 0)
 
-    def _test_linter_finds_no_errors(self, path, commit_id=None):
-        linter = MigrationLinter(path, database=self.DATABASE, no_cache=True)
-        linter.lint_all_migrations(git_commit_id=commit_id)
+    def _test_linter_finds_no_errors(self, app=None, commit_id=None):
+        linter = self._launch_linter(app, commit_id)
         self.assertFalse(linter.has_errors)
+        self.assertNotEqual(linter.nb_valid + linter.nb_erroneous, 0)
+
+    def _launch_linter(self, app=None, commit_id=None):
+        if app is not None:
+            app = [app]
+
+        linter = MigrationLinter(
+            self.test_project_path,
+            include_apps=app,
+            database=next(iter(self.databases)),
+            no_cache=True,
+        )
+        linter.lint_all_migrations(git_commit_id=commit_id)
+        return linter
 
     # *** Tests ***
     def test_create_table_with_not_null_column(self):
-        test_project_path = fixtures.CREATE_TABLE_WITH_NOT_NULL_COLUMN_PROJECT
-        self._test_linter_finds_no_errors(test_project_path)
+        app = fixtures.CREATE_TABLE_WITH_NOT_NULL_COLUMN
+        self._test_linter_finds_no_errors(app)
 
     def test_detect_adding_not_null_column(self):
-        test_project_path = fixtures.ADD_NOT_NULL_COLUMN_PROJECT
-        self._test_linter_finds_errors(test_project_path)
+        app = fixtures.ADD_NOT_NULL_COLUMN
+        self._test_linter_finds_errors(app)
 
     def test_detect_drop_column(self):
-        test_project_path = fixtures.DROP_COLUMN_PROJECT
-        self._test_linter_finds_errors(test_project_path)
+        app = fixtures.DROP_COLUMN
+        self._test_linter_finds_errors(app)
 
     def test_detect_rename_column(self):
-        test_project_path = fixtures.RENAME_COLUMN_PROJECT
-        self._test_linter_finds_errors(test_project_path)
+        app = fixtures.RENAME_COLUMN
+        self._test_linter_finds_errors(app)
 
     def test_detect_rename_table(self):
-        test_project_path = fixtures.RENAME_TABLE_PROJECT
-        self._test_linter_finds_errors(test_project_path)
+        app = fixtures.RENAME_TABLE
+        self._test_linter_finds_errors(app)
 
     def test_ignore_migration(self):
-        test_project_path = fixtures.IGNORE_MIGRATION_PROJECT
-        self._test_linter_finds_no_errors(test_project_path)
+        app = fixtures.IGNORE_MIGRATION
+        self._test_linter_finds_no_errors(app)
 
     def test_accept_not_null_column_followed_by_adding_default(self):
-        test_project_path = \
-            fixtures.ADD_NOT_NULL_COLUMN_FOLLOWED_BY_DEFAULT_PROJECT
-        self._test_linter_finds_no_errors(test_project_path)
+        app = fixtures.ADD_NOT_NULL_COLUMN_FOLLOWED_BY_DEFAULT
+        self._test_linter_finds_no_errors(app)
 
     def test_detect_alter_column(self):
-        test_project_path = fixtures.ALTER_COLUMN_PROJECT
-        self._test_linter_finds_errors(test_project_path)
+        app = fixtures.ALTER_COLUMN
+        self._test_linter_finds_errors(app)
 
-    def test_no_specify_git_hash(self):
-        test_project_path = fixtures.MULTI_COMMIT_PROJECT
-        fixtures.prepare_git_project(test_project_path)
-        self._test_linter_finds_errors(test_project_path, commit_id=None)
-
-    def test_specify_git_hash_by_commit_hash(self):
-        test_project_path = fixtures.MULTI_COMMIT_PROJECT
-        fixtures.prepare_git_project(test_project_path)
-        self._test_linter_finds_no_errors(
-            test_project_path,
-            commit_id='d7125d5f4f0cc9623f670a66c54f131acc50032d')
-
-    #def test_specify_git_hash_by_tag(self):
-    #    test_project_path = fixtures.MULTI_COMMIT_PROJECT
-    #    fixtures.prepare_git_project(test_project_path)
-    #    self._test_linter_finds_no_errors(test_project_path, commit_id='tag1')
+    def test_with_git_ref(self):
+        self._test_linter_finds_errors(commit_id="v0.1.4")
 
 
-class MySqlBackwardCompatibilityDetectionTest(unittest.TestCase, BaseBackwardCompatibilityDetection):
-    DATABASE = "mysql"
-
-class SqliteBackwardCompatibilityDetectionTest(unittest.TestCase, BaseBackwardCompatibilityDetection):
-    DATABASE = "sqlite"
+class SqliteBackwardCompatibilityDetectionTestCase(
+    BaseBackwardCompatibilityDetection, unittest.TestCase
+):
+    databases = ["sqlite"]
 
     def test_accept_not_null_column_followed_by_adding_default(self):
-        test_project_path = \
-            fixtures.ADD_NOT_NULL_COLUMN_FOLLOWED_BY_DEFAULT_PROJECT
-        self._test_linter_finds_errors(test_project_path)
-
-    def test_specify_git_hash_by_commit_hash(self):
-        test_project_path = fixtures.MULTI_COMMIT_PROJECT
-        fixtures.prepare_git_project(test_project_path)
-        self._test_linter_finds_errors(
-            test_project_path,
-            commit_id='d7125d5f4f0cc9623f670a66c54f131acc50032d')
+        app = fixtures.ADD_NOT_NULL_COLUMN_FOLLOWED_BY_DEFAULT
+        self._test_linter_finds_errors(app)
 
 
-class PostgresqlBackwardCompatibilityDetectionTest(unittest.TestCase, BaseBackwardCompatibilityDetection):
-    DATABASE = "postgresql"
+class MySqlBackwardCompatibilityDetectionTestCase(
+    BaseBackwardCompatibilityDetection, unittest.TestCase
+):
+    databases = ["mysql"]
+
+
+class PostgresqlBackwardCompatibilityDetectionTestCase(
+    BaseBackwardCompatibilityDetection, unittest.TestCase
+):
+    databases = ["postgresql"]