strict return types (#1320)

Author: romainmenke

.eslintrc.json

@@ -37,7 +37,8 @@
 			"rules": {
 				"no-shadow": "off",
 				"@typescript-eslint/no-shadow": "error",
-				"@typescript-eslint/array-type": ["error", { "default": "generic" }]
+				"@typescript-eslint/array-type": ["error", { "default": "generic" }],
+				"@typescript-eslint/explicit-function-return-type": "error"
 			}
 		}
 	]

cli/csstools-cli/src/cli.ts

@@ -48,7 +48,7 @@ import postcssTrigonometricFunctions from './plugins/postcss-trigonometric-funct
 import postcssUnsetValue from './plugins/postcss-unset-value';
 
 main();
-function main() {
+function main(): void {
 	switch (process.argv[2] ?? false) {
 		case 'css-blank-pseudo':
 			cssBlankPseudo();