Switch to @eslint/json (#1749)

Replaces `eslint-plugin-jsonc` by `@eslint/json`.

Following [1] this replaces `eslint-plugin-jsonc` by `@eslint/json`
for linting JSON(C) in this project. The motivation for this change is
supported by the FAQ of the new package.

The reduction in rules is further motivated by ESLint's general move
away from formatting-like rules to lint-like rules, which I believe
makes sense for the present project given the use of Prettier.

--
1. https://eslint.org/blog/2024/10/eslint-json-markdown-support/

config/eslint.js

@@ -2,7 +2,7 @@
 
 import ava from "eslint-plugin-ava";
 import jsdoc from "eslint-plugin-jsdoc";
-import jsonc from "eslint-plugin-jsonc";
+import json from "@eslint/json";
 import regexp from "eslint-plugin-regexp";
 import top from "@ericcornelissen/eslint-plugin-top";
 import yml from "eslint-plugin-yml";
@@ -622,81 +622,27 @@ export default [
   },
   {
     name: "JSON",
-    files: [
-      "config/**/*.json",
-      "config/**/*.jsonc",
-      ".licensee.json",
-      "package-lock.json",
-      "package.json",
-    ],
-    plugins: { jsonc },
+    files: ["config/**/*.json", ".licensee.json", "package.json"],
+    plugins: { json },
+    language: "json/json",
     rules: {
-      "no-irregular-whitespace": ["off"],
-
-      // https://ota-meshi.github.io/eslint-plugin-jsonc/rules/
-      "jsonc/array-bracket-newline": ["off"],
-      "jsonc/array-bracket-spacing": ["off"],
-      "jsonc/array-element-newline": ["off"],
-      "jsonc/comma-dangle": ["off"],
-      "jsonc/comma-style": ["error", "last"],
-      "jsonc/indent": ["error", 2],
-      "jsonc/key-name-casing": ["off"],
-      "jsonc/key-spacing": [
-        "error",
-        {
-          afterColon: true,
-          beforeColon: false,
-          mode: "strict",
-        },
-      ],
-      "jsonc/no-bigint-literals": ["error"],
-      "jsonc/no-binary-expression": ["error"],
-      "jsonc/no-binary-numeric-literals": ["error"],
-      "jsonc/no-comments": ["off"],
-      "jsonc/no-dupe-keys": ["error"],
-      "jsonc/no-escape-sequence-in-identifier": ["error"],
-      "jsonc/no-floating-decimal": ["error"],
-      "jsonc/no-hexadecimal-numeric-literals": ["error"],
-      "jsonc/no-infinity": ["error"],
-      "jsonc/no-irregular-whitespace": [
-        "error",
-        {
-          skipStrings: true,
-          skipComments: false,
-          skipRegExps: false,
-          skipTemplates: false,
-        },
-      ],
-      "jsonc/no-multi-str": ["error"],
-      "jsonc/no-nan": ["error"],
-      "jsonc/no-number-props": ["error"],
-      "jsonc/no-numeric-separators": ["error"],
-      "jsonc/no-octal": ["error"],
-      "jsonc/no-octal-escape": ["error"],
-      "jsonc/no-octal-numeric-literals": ["error"],
-      "jsonc/no-parenthesized": ["error"],
-      "jsonc/no-plus-sign": ["error"],
-      "jsonc/no-regexp-literals": ["error"],
-      "jsonc/no-sparse-arrays": ["error"],
-      "jsonc/no-template-literals": ["error"],
-      "jsonc/no-undefined-value": ["error"],
-      "jsonc/no-unicode-codepoint-escapes": ["error"],
-      "jsonc/no-useless-escape": ["error"],
-      "jsonc/object-curly-newline": ["off"],
-      "jsonc/object-curly-spacing": ["off"],
-      "jsonc/object-property-newline": ["off"],
-      "jsonc/quote-props": ["error", "always"],
-      "jsonc/quotes": [
-        "error",
-        "double",
-        {
-          avoidEscape: false,
-        },
-      ],
-      "jsonc/sort-array-values": ["off"],
-      "jsonc/sort-keys": ["off"],
-      "jsonc/space-unary-ops": ["error"],
-      "jsonc/valid-json-number": ["error"],
+      // https://github.com/eslint/json/blob/main/README.md#rules
+      "json/no-duplicate-keys": ["error"],
+      "json/no-empty-keys": ["error"],
+    },
+  },
+  {
+    name: "JSONC",
+    files: ["config/**/*.jsonc"],
+    plugins: { json },
+    language: "json/jsonc",
+    languageOptions: {
+      allowTrailingCommas: true,
+    },
+    rules: {
+      // https://github.com/eslint/json/blob/main/README.md#rules
+      "json/no-duplicate-keys": ["error"],
+      "json/no-empty-keys": ["error"],
     },
   },
   {
@@ -775,6 +721,5 @@ export default [
     ],
   },
 
-  ...jsonc.configs["flat/base"],
   ...yml.configs["flat/base"],
 ];

package.json

@@ -64,6 +64,7 @@
   "devDependencies": {
     "@arethetypeswrong/cli": "0.16.4",
     "@ericcornelissen/eslint-plugin-top": "3.4.0",
+    "@eslint/json": "0.6.0",
     "@fast-check/ava": "2.0.1",
     "@stryker-mutator/core": "8.6.0",
     "@stryker-mutator/tap-runner": "8.6.0",
@@ -74,7 +75,6 @@
     "eslint": "9.13.0",
     "eslint-plugin-ava": "15.0.0",
     "eslint-plugin-jsdoc": "50.4.1",
-    "eslint-plugin-jsonc": "2.15.1",
     "eslint-plugin-regexp": "2.6.0",
     "eslint-plugin-yml": "1.14.0",
     "fast-check": "3.22.0",