Type annotations (#460)

* round 1: clean, but lots of ignore

* round 2: ignore less

* ruff check

* ruff format

* update and tighten mypy configuration

* pipeline fixes

Author: dimbleby

poetry.lock

@@ -28,7 +28,7 @@ pytest = "^7.2.0"
 pytest-cov = "^4.0.0"
 PyYAML = "^6.0"
 pre-commit = "^2.20.0"
-mypy = "^0.990"
+mypy = "1.19.1"
 Sphinx = "^4.3.2"
 furo = "^2022.9.29"
 
@@ -54,6 +54,15 @@ force-single-line = true
 lines-after-imports = 2
 lines-between-types = 1
 
+[tool.mypy]
+files = "tomlkit, tests"
+strict = true
+enable_error_code = [
+    "ignore-without-code",
+    "redundant-expr",
+    "truthy-bool",
+]
+
 [build-system]
 requires = ["poetry-core>=1.0.0a9"]
 build-backend = "poetry.core.masonry.api"

pyproject.toml

@@ -1,11 +1,13 @@
 import os
 
+from collections.abc import Callable
+
 import pytest
 
 
 @pytest.fixture
-def example():
-    def _example(name):
+def example() -> Callable[[str], str]:
+    def _example(name: str) -> str:
         with open(
             os.path.join(os.path.dirname(__file__), "examples", name + ".toml"),
             encoding="utf-8",
@@ -16,8 +18,8 @@ def _example(name):
 
 
 @pytest.fixture
-def json_example():
-    def _example(name):
+def json_example() -> Callable[[str], str]:
+    def _example(name: str) -> str:
         with open(
             os.path.join(os.path.dirname(__file__), "examples", "json", name + ".json"),
             encoding="utf-8",
@@ -28,8 +30,8 @@ def _example(name):
 
 
 @pytest.fixture
-def invalid_example():
-    def _example(name):
+def invalid_example() -> Callable[[str], str]:
+    def _example(name: str) -> str:
         with open(
             os.path.join(
                 os.path.dirname(__file__), "examples", "invalid", name + ".toml"