Update to ESLint v9

eslint.config.mjs

@@ -0,0 +1,52 @@
+import configurations from '@plugjs/eslint-plugin'
+
+export default [
+  ...configurations,
+
+  // ===== DEFINE THE LOCATION OF OUR TSCONFIG.JSON FILES ======================
+  {
+    languageOptions: {
+      parserOptions: {
+        createDefaultProgram: false,
+        project: [
+          './tsconfig.json',
+          './test/tsconfig.json',
+        ],
+      },
+    },
+  },
+
+  // ===== ENSURE THAT OUR MAIN FILES DEPEND ONLY ON PROPER DEPENDENCIES =======
+  {
+    files: [ 'src/**' ],
+    rules: {
+      // Turn _ON_ dependencies checks only for sources
+      'import-x/no-extraneous-dependencies': [ 'error', {
+        'devDependencies': true,
+        'peerDependencies': true,
+        'optionalDependencies': true,
+        'bundledDependencies': false,
+      } ],
+    },
+  },
+
+  // ===== PROJECT LOCAL RULES =================================================
+  // Add any extra rule not tied to a specific "files" pattern here, e.g.:
+  // {
+  //   rules: {
+  //     'camelcase': 'off',
+  //   },
+  // },
+
+  // ===== IGNORED FILES =======================================================
+  // REMEMBER! Ignores *must* be in its own configuration, they can not coexist
+  // with "rules", "languageOptions", "files", ... or anything else, otherwise
+  // ESLint will blaantly ignore the ignore files!
+  {
+    ignores: [
+      'coverage/',
+      'dist/',
+      'node_modules/',
+    ],
+  },
+]