style: adopt ruff (format + lint) at 88, replacing black/isort/flake8

Format-only: Python files are AST-identical apart from import order.
pre-commit end-of-file/trailing-whitespace fixes applied repo-wide.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/README.md

@@ -15,4 +15,3 @@ Run test by keyword:
 Run test by directory:
 
     pytest <dirname>
-  

tests/cfg/sample_config.ini

@@ -2,4 +2,3 @@ root_option = root_option_val
 
 [app]
     sub_option = sub_option_val
-

tests/cfg/sample_config.spec

@@ -2,4 +2,3 @@ root_option = string(max=255, default='def_string')
 
 [app]
     sub_option = string(max=255, default='def_sub')
-

tests/cfg/sample_config_full.ini

@@ -2,4 +2,3 @@ root_option = root_option_val
 
 [app]
     sub_option = sub_option_val
-

tests/cfg/sample_config_full.spec

@@ -3,4 +3,3 @@ int_option = integer(min=0, max=100)
 
 [app]
     sub_option = string(max=255, default='def_sub')
-

tests/cfg/sample_config_invalid.spec

@@ -1,2 +1 @@
 root_option = invalid(max=255, default='def_string')
-

tests/cfg/test_cfg.py

@@ -32,18 +32,18 @@ def sample_invalid_configspec_filepath():
 class TestConfig_e2e:
     def test_allows_reading_ini_and_no_spec(self, sample_configini_filepath):
         cfg = Config(configini_filepath=sample_configini_filepath)
-        assert (
-            cfg["root_option"] == "root_option_val"
-        ), "expecting default from config.spec (didnt get)"
-        assert (
-            cfg["app"]["sub_option"] == "sub_option_val"
-        ), "expecting default for sub option"
+        assert cfg["root_option"] == "root_option_val", (
+            "expecting default from config.spec (didnt get)"
+        )
+        assert cfg["app"]["sub_option"] == "sub_option_val", (
+            "expecting default for sub option"
+        )
 
     def test_allows_reading_spec_and_no_ini(self, sample_configspec_filepath):
         cfg = Config(configspec_filepath=sample_configspec_filepath)
-        assert (
-            cfg["root_option"] == "def_string"
-        ), "expecting default from config.spec (didnt get)"
+        assert cfg["root_option"] == "def_string", (
+            "expecting default from config.spec (didnt get)"
+        )
 
     # NOTE(MG) Changed the functionality to not do it this way.
     # def test_constructor_fails_with_invalid_spec(
@@ -71,9 +71,9 @@ class TestConfig_e2e:
         assert cfg["root_option"] == "newval"
 
         cfg["app"]["sub_option"] = "another_new_val"
-        assert (
-            cfg["app"]["sub_option"] == "another_new_val"
-        ), "expecting default for sub option"
+        assert cfg["app"]["sub_option"] == "another_new_val", (
+            "expecting default for sub option"
+        )
 
     def test_can_set_option_without_config(self):
         cfg = Config()
@@ -86,7 +86,7 @@ class TestConfig_e2e:
 
     def test_uses_spec_as_defaults(self, sample_configspec_filepath):
         cfg = Config(configspec_filepath=sample_configspec_filepath)
-        assert (
-            cfg["root_option"] == "def_string"
-        ), "expecting default from config.spec (didnt get)"
+        assert cfg["root_option"] == "def_string", (
+            "expecting default from config.spec (didnt get)"
+        )
         assert cfg["app"]["sub_option"] == "def_sub", "expecting default for sub option"

tests/pytest.ini

@@ -1,4 +1,3 @@
 [pytest]
 filterwarnings =
     ignore::DeprecationWarning
-