refactor(eslint): update to ESLint 9

.textlintrc.js

@@ -97,7 +97,7 @@ module.exports = {
             }
         },
         "eslint": {
-            "configFile": "./config/markdown.eslintrc.cjs"
+            "configFile": "./eslint.config.mjs"
         },
         "prh": {
             "rulePaths": [

eslint.config.mjs

@@ -0,0 +1,76 @@
+export default [{
+    ignores: [
+        "**/node_modules/",
+        "**/build.js",
+        "**/build/",
+        "**/html-like-comments-example.js",
+        "**/*-invalid.js",
+        "**/invalid/**/*.js",
+    ],
+}, {
+    languageOptions: {
+        ecmaVersion: 2024,
+        sourceType: "module",
+    },
+
+    rules: {
+        // サンプルコードで概念的な関数を使うことがあるため
+        "no-undef": "off",
+        // サンプルコードで変数を宣言していないことがあるため
+        "no-unused-vars": "off",
+        // サンプルコードで console を使うことがあるため
+        "no-console": "off",
+        // 名前の分かりやすさのために制限する
+        // 詳細: https://github.com/asciidwango/js-primer/issues/804
+        "id-blacklist": ["error", "string", "number", "object", "boolean", "symbol"],
+
+        indent: ["error", 4, {
+            SwitchCase: 1,
+        }],
+
+        quotes: ["error", "double", {
+            allowTemplateLiterals: true,
+        }],
+
+        "array-bracket-spacing": ["error", "never"],
+        "brace-style": ["error", "1tbs"],
+        "block-spacing": "error",
+        "comma-spacing": "error",
+        "computed-property-spacing": "error",
+        "no-whitespace-before-property": "error",
+        "object-curly-newline": ["off", "always"],
+        "object-curly-spacing": ["error", "always"],
+        "key-spacing": "error",
+        "keyword-spacing": "error",
+        "linebreak-style": ["error", "unix"],
+        "no-multiple-empty-lines": "error",
+        "rest-spread-spacing": "error",
+        semi: ["error", "always"],
+        "semi-spacing": "error",
+        "space-before-blocks": "error",
+        "space-before-function-paren": ["error", "never"],
+        "space-in-parens": "error",
+        "space-infix-ops": "error",
+        "space-unary-ops": "error",
+
+        "spaced-comment": ["error", "always", {
+            exceptions: ["-", "=", "!"],
+
+            markers: [
+                "eslint",
+                "eslint-env",
+                "eslint-disable",
+                "eslint-enable",
+                "eslint-disable-line",
+                "eslint-disable-next-line",
+                "exported",
+                "globals",
+                "istanbul",
+                "!",
+            ],
+        }],
+
+        "prefer-const": "error",
+        "no-var": "error",
+    },
+}];