refactor(db_engine_specs): Removing top-level import of app (#14366)

Co-authored-by: John Bodley <john.bodley@airbnb.com>

tests/db_engine_specs/base_engine_spec_tests.py

@@ -167,25 +167,6 @@ class TestDbEngineSpecs(TestDbEngineSpec):
             "SELECT * FROM table", "SELECT * FROM table", DummyEngineSpec
         )
 
-    def test_time_grain_denylist(self):
-        with app.app_context():
-            app.config["TIME_GRAIN_DENYLIST"] = ["PT1M"]
-            time_grain_functions = SqliteEngineSpec.get_time_grain_expressions()
-            self.assertNotIn("PT1M", time_grain_functions)
-
-    def test_time_grain_addons(self):
-        with app.app_context():
-            app.config["TIME_GRAIN_ADDONS"] = {"PTXM": "x seconds"}
-            app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {
-                "sqlite": {"PTXM": "ABC({col})"}
-            }
-            time_grains = SqliteEngineSpec.get_time_grains()
-            time_grain_addon = time_grains[-1]
-            self.assertEqual("PTXM", time_grain_addon.duration)
-            self.assertEqual("x seconds", time_grain_addon.label)
-            app.config["TIME_GRAIN_ADDONS"] = {}
-            app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {}
-
     def test_engine_time_grain_validity(self):
         time_grains = set(builtin_time_grains.keys())
         # loop over all subclasses of BaseEngineSpec
@@ -198,43 +179,6 @@ class TestDbEngineSpecs(TestDbEngineSpec):
                 intersection = time_grains.intersection(defined_grains)
                 self.assertSetEqual(defined_grains, intersection, engine)
 
-    def test_get_time_grain_with_config(self):
-        """ Should concatenate from configs and then sort in the proper order """
-        app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {
-            "mysql": {
-                "PT2H": "foo",
-                "PT4H": "foo",
-                "PT6H": "foo",
-                "PT8H": "foo",
-                "PT10H": "foo",
-                "PT12H": "foo",
-                "PT1S": "foo",
-            }
-        }
-        time_grains = MySQLEngineSpec.get_time_grain_expressions()
-        self.assertEqual(
-            list(time_grains.keys()),
-            [
-                None,
-                "PT1S",
-                "PT1M",
-                "PT1H",
-                "PT2H",
-                "PT4H",
-                "PT6H",
-                "PT8H",
-                "PT10H",
-                "PT12H",
-                "P1D",
-                "P1W",
-                "P1M",
-                "P0.25Y",
-                "P1Y",
-                "1969-12-29T00:00:00Z/P1W",
-            ],
-        )
-        app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {}
-
     def test_get_time_grain_expressions(self):
         time_grains = MySQLEngineSpec.get_time_grain_expressions()
         self.assertEqual(
@@ -253,18 +197,6 @@ class TestDbEngineSpecs(TestDbEngineSpec):
             ],
         )
 
-    def test_get_time_grain_with_unkown_values(self):
-        """Should concatenate from configs and then sort in the proper order
-        putting unknown patterns at the end"""
-        app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {
-            "mysql": {"PT2H": "foo", "weird": "foo", "PT12H": "foo",}
-        }
-        time_grains = MySQLEngineSpec.get_time_grain_expressions()
-        self.assertEqual(
-            list(time_grains)[-1], "weird",
-        )
-        app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {}
-
     def test_get_table_names(self):
         inspector = mock.Mock()
         inspector.get_table_names = mock.Mock(return_value=["schema.table", "table_2"])
@@ -339,3 +271,84 @@ def test_is_readonly():
     assert is_readonly("WITH (SELECT 1) bla SELECT * from bla")
     assert is_readonly("SHOW CATALOGS")
     assert is_readonly("SHOW TABLES")
+
+
+def test_time_grain_denylist():
+    config = app.config.copy()
+    app.config["TIME_GRAIN_DENYLIST"] = ["PT1M"]
+
+    with app.app_context():
+        time_grain_functions = SqliteEngineSpec.get_time_grain_expressions()
+        assert not "PT1M" in time_grain_functions
+
+    app.config = config
+
+
+def test_time_grain_addons():
+    config = app.config.copy()
+    app.config["TIME_GRAIN_ADDONS"] = {"PTXM": "x seconds"}
+    app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {"sqlite": {"PTXM": "ABC({col})"}}
+
+    with app.app_context():
+        time_grains = SqliteEngineSpec.get_time_grains()
+        time_grain_addon = time_grains[-1]
+        assert "PTXM" == time_grain_addon.duration
+        assert "x seconds" == time_grain_addon.label
+
+    app.config = config
+
+
+def test_get_time_grain_with_config():
+    """ Should concatenate from configs and then sort in the proper order """
+    config = app.config.copy()
+
+    app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {
+        "mysql": {
+            "PT2H": "foo",
+            "PT4H": "foo",
+            "PT6H": "foo",
+            "PT8H": "foo",
+            "PT10H": "foo",
+            "PT12H": "foo",
+            "PT1S": "foo",
+        }
+    }
+
+    with app.app_context():
+        time_grains = MySQLEngineSpec.get_time_grain_expressions()
+        assert set(time_grains.keys()) == {
+            None,
+            "PT1S",
+            "PT1M",
+            "PT1H",
+            "PT2H",
+            "PT4H",
+            "PT6H",
+            "PT8H",
+            "PT10H",
+            "PT12H",
+            "P1D",
+            "P1W",
+            "P1M",
+            "P0.25Y",
+            "P1Y",
+            "1969-12-29T00:00:00Z/P1W",
+        }
+
+    app.config = config
+
+
+def test_get_time_grain_with_unkown_values():
+    """Should concatenate from configs and then sort in the proper order
+    putting unknown patterns at the end"""
+    config = app.config.copy()
+
+    app.config["TIME_GRAIN_ADDON_EXPRESSIONS"] = {
+        "mysql": {"PT2H": "foo", "weird": "foo", "PT12H": "foo",}
+    }
+
+    with app.app_context():
+        time_grains = MySQLEngineSpec.get_time_grain_expressions()
+        assert list(time_grains)[-1] == "weird"
+
+    app.config = config