chore(deps-dev): migrate to ESLint v9

Author: kleinfreund

.eslintignore

@@ -31,17 +31,17 @@ type ColorRgb = {
     b: number;
     a: number;
 };
-type ColorMap = {
+interface ColorMap {
     hex: string;
     hsl: ColorHsl;
     hsv: ColorHsv;
     hwb: ColorHwb;
     rgb: ColorRgb;
-};
-type ColorChangeDetail = {
+}
+interface ColorChangeDetail {
     colors: ColorMap;
     cssColor: string;
-};
+}
 type ColorFormat = keyof ColorMap;
 type VisibleColorFormat = Exclude<ColorFormat, 'hsv'>;
 interface ColorPairHex {

.eslintrc.cjs

@@ -0,0 +1,44 @@
+import eslint from '@eslint/js'
+import stylistic from '@stylistic/eslint-plugin'
+import globals from 'globals'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+	{
+		ignores: ['coverage/', 'dist/'],
+	},
+	eslint.configs.recommended,
+	...tseslint.configs.strict,
+	...tseslint.configs.stylistic,
+	{
+		files: ['**/*.{js,ts}'],
+		languageOptions: {
+			globals: {
+				...globals.browser,
+			},
+		},
+		plugins: {
+			'@stylistic': stylistic,
+		},
+		rules: {
+			// Interferes with `get [Symbol.toStringTag]`.
+			'@typescript-eslint/class-literal-property-style': 'off',
+			// Don't care.
+			'@typescript-eslint/no-non-null-assertion': 'off',
+			// Intereferes with assigning Color* object types to `Record<string, unknown>`.
+			'@typescript-eslint/consistent-type-definitions': 'off',
+
+			'@stylistic/comma-dangle': ['error', 'always-multiline'],
+			'@stylistic/indent': ['error', 'tab'],
+			'@stylistic/semi': ['error', 'never'],
+			'@stylistic/space-before-function-paren': ['error', 'always'],
+			'@stylistic/quotes': ['error', 'single'],
+		},
+	},
+	{
+		files: ['**/*.test.{js,ts}'],
+		rules: {
+			'@typescript-eslint/ban-ts-comment': 'off',
+		},
+	},
+)