Add +x to scripts; type check tests; add toml

pyproject.toml

@@ -44,7 +44,7 @@ full = [
 dev = [
     "black",
     "build",
-    "coverage",
+    "coverage[toml]",
     "flake8",
     "mkdocs-material",
     "mkdocstrings[python]",
@@ -65,7 +65,10 @@ version = {attr = "PACKAGE_NAME_PLACEHOLDER.__version__"}
 # Mypy: #
 
 [tool.mypy]
-files = "src/"
+files = [
+    "src/",
+    "tests/",
+]
 warn_unused_configs = true
 strict = true
 show_error_codes = true

requirements/dev.txt

@@ -1,7 +1,7 @@
 -r common.txt
 black
 build
-coverage
+coverage[toml]
 flake8
 mkdocs-material
 mkdocstrings[python]