feat: support flat config (and thus ESLint 9)

Also:
- chore: use flat config internally
- chore: update devDeps.
- chore: prettify files

.ncurc.js

@@ -2,5 +2,5 @@ module.exports = {
   // Whitelist all for checking besides `peer` which indicates
   //   somewhat older versions of `eslint` we still support even
   //   while our devDeps point to a more recent version
-  "dep": "prod,dev,optional,bundle"
+  dep: 'prod,dev,optional,bundle',
 };

eslint.config.mjs

@@ -0,0 +1,27 @@
+// import standard from "eslint-config-standard"
+import eslintPluginPrettierRecommended from 'eslint-plugin-prettier/recommended';
+import globals from 'globals';
+
+export default [
+  {
+    languageOptions: {
+      globals: {
+        ...globals.browser,
+        ...globals.node,
+        ...globals.es2015,
+      },
+    },
+    rules: {
+      'no-var': [2],
+      'prefer-destructuring': [2],
+      'object-shorthand': [2],
+    },
+  },
+  {
+    files: ['tests/lib/utils/**'],
+    languageOptions: {
+      globals: globals.mocha,
+    },
+  },
+  eslintPluginPrettierRecommended,
+];

lib/index.js

@@ -19,42 +19,52 @@ const requireIndex = require('requireindex');
 // import all rules in lib/rules
 module.exports = {
   rules: requireIndex(path.resolve(__dirname, './rules')),
-  configs: {
-    recommended: {
-      plugins: ['mocha-cleanup'],
-      rules: {
-        'mocha-cleanup/asserts-limit': 2,
-        'mocha-cleanup/disallow-stub-spy-restore-in-it': 2,
-        'mocha-cleanup/no-empty-title': 2,
-        'mocha-cleanup/no-same-titles': 2,
-        'mocha-cleanup/no-nested-it': 2,
-        'mocha-cleanup/no-assertions-outside-it': 2,
-        'mocha-cleanup/complexity-it': 2,
-        'mocha-cleanup/no-eql-primitives': 2,
-        'mocha-cleanup/no-assertions-in-loop': 2,
-        'mocha-cleanup/no-empty-body': 2,
-        'mocha-cleanup/invalid-assertions': 2,
-        'mocha-cleanup/no-expressions-in-assertions': 2,
-        'mocha-cleanup/no-outside-declaration': 2,
-      },
+  configs: {},
+};
+
+for (const prefix of ['flat/', '']) {
+  module.exports.configs[prefix + 'recommended'] = {
+    rules: {
+      'mocha-cleanup/asserts-limit': 2,
+      'mocha-cleanup/disallow-stub-spy-restore-in-it': 2,
+      'mocha-cleanup/no-empty-title': 2,
+      'mocha-cleanup/no-same-titles': 2,
+      'mocha-cleanup/no-nested-it': 2,
+      'mocha-cleanup/no-assertions-outside-it': 2,
+      'mocha-cleanup/complexity-it': 2,
+      'mocha-cleanup/no-eql-primitives': 2,
+      'mocha-cleanup/no-assertions-in-loop': 2,
+      'mocha-cleanup/no-empty-body': 2,
+      'mocha-cleanup/invalid-assertions': 2,
+      'mocha-cleanup/no-expressions-in-assertions': 2,
+      'mocha-cleanup/no-outside-declaration': 2,
     },
-    'recommended-no-limits': {
-      plugins: ['mocha-cleanup'],
-      rules: {
-        // "mocha-cleanup/asserts-limit": 0,
-        'mocha-cleanup/disallow-stub-spy-restore-in-it': 2,
-        'mocha-cleanup/no-empty-title': 2,
-        'mocha-cleanup/no-same-titles': 2,
-        'mocha-cleanup/no-nested-it': 2,
-        'mocha-cleanup/no-assertions-outside-it': 2,
-        // "mocha-cleanup/complexity-it": 0,
-        'mocha-cleanup/no-eql-primitives': 2,
-        'mocha-cleanup/no-assertions-in-loop': 2,
-        'mocha-cleanup/no-empty-body': 2,
-        'mocha-cleanup/invalid-assertions': 2,
-        'mocha-cleanup/no-expressions-in-assertions': 2,
-        'mocha-cleanup/no-outside-declaration': 2,
-      },
+  };
+
+  module.exports.configs[prefix + 'recommended-no-limits'] = {
+    rules: {
+      // "mocha-cleanup/asserts-limit": 0,
+      'mocha-cleanup/disallow-stub-spy-restore-in-it': 2,
+      'mocha-cleanup/no-empty-title': 2,
+      'mocha-cleanup/no-same-titles': 2,
+      'mocha-cleanup/no-nested-it': 2,
+      'mocha-cleanup/no-assertions-outside-it': 2,
+      // "mocha-cleanup/complexity-it": 0,
+      'mocha-cleanup/no-eql-primitives': 2,
+      'mocha-cleanup/no-assertions-in-loop': 2,
+      'mocha-cleanup/no-empty-body': 2,
+      'mocha-cleanup/invalid-assertions': 2,
+      'mocha-cleanup/no-expressions-in-assertions': 2,
+      'mocha-cleanup/no-outside-declaration': 2,
     },
-  },
+  };
+}
+
+module.exports.configs.recommended.plugins = ['mocha-cleanup'];
+module.exports.configs['recommended-no-limits'].plugins = ['mocha-cleanup'];
+module.exports.configs['flat/recommended'].plugins = {
+  'mocha-cleanup': module.exports,
+};
+module.exports.configs['flat/recommended-no-limits'].plugins = {
+  'mocha-cleanup': module.exports,
 };

lib/rules/asserts-limit.js

@@ -48,7 +48,7 @@ module.exports = {
     const skipSkipped = isSkipSkipped(options, context);
     const ignoreZeroAssertionsIfDoneExists = hasOwnProperty.call(
       options,
-      'ignoreZeroAssertionsIfDoneExists'
+      'ignoreZeroAssertionsIfDoneExists',
     )
       ? options.ignoreZeroAssertionsIfDoneExists
       : true;
@@ -83,7 +83,7 @@ module.exports = {
             {
               max: assertsLimit,
               num: assertsCounter,
-            }
+            },
           );
         }
         if (
@@ -93,7 +93,7 @@ module.exports = {
         ) {
           context.report(
             node.parent,
-            'Test without assertions is not allowed.'
+            'Test without assertions is not allowed.',
           );
         }
         insideIt = false;

lib/rules/complexity-it.js

@@ -43,7 +43,7 @@ module.exports = {
     const options = context.options[0] || {};
     const maxAllowedComplexity = hasOwnProperty.call(
       options,
-      'maxAllowedComplexity'
+      'maxAllowedComplexity',
     )
       ? options.maxAllowedComplexity
       : 40;
@@ -79,7 +79,7 @@ module.exports = {
               max: maxAllowedComplexity,
               num: currentComplexityCount,
               name: n.getCaller(node.parent),
-            }
+            },
           );
         }
         insideIt = false;

lib/rules/disallow-stub-spy-restore-in-it.js

@@ -71,7 +71,7 @@ module.exports = {
           context.report(
             node,
             '`{{name}}` is not allowed to use inside `{{caller}}`.',
-            { name: _c, caller }
+            { name: _c, caller },
           );
         }
       },

lib/rules/no-assertions-in-loop.js

@@ -51,7 +51,7 @@ module.exports = {
     const skipSkipped = isSkipSkipped(options, context);
     const extraMemberExpression = hasOwnProperty.call(
       options,
-      'extraMemberExpression'
+      'extraMemberExpression',
     )
       ? options.extraMemberExpression
       : [];

lib/rules/no-eql-primitives.js

@@ -77,7 +77,7 @@ module.exports = {
                 context.report(
                   node,
                   '`{{caller}}` should not be used with primitives.',
-                  { caller }
+                  { caller },
                 );
               }
             }
@@ -103,7 +103,7 @@ module.exports = {
                 context.report(
                   node,
                   '`{{caller}}` should not be used with primitives.',
-                  { caller: _caller }
+                  { caller: _caller },
                 );
               }
             }

lib/rules/no-nested-it.js

@@ -41,7 +41,7 @@ module.exports = {
         if (insideIt && !(skipSkipped && n.tryDetectSkipInParent(node))) {
           context.report(
             node.parent,
-            'Nested tests are not allowed. Only nested suites are allowed.'
+            'Nested tests are not allowed. Only nested suites are allowed.',
           );
         } else {
           insideIt = true;

lib/rules/top-level-assertions.js

@@ -77,7 +77,7 @@ module.exports = {
         const nodeSourceCode = context.getSourceCode().getText(node);
         if (assertionsCheckExpression) {
           assertionsCheckExists = RegExp(assertionsCheckExpression, 'gm').test(
-            nodeSourceCode
+            nodeSourceCode,
           );
         }
         insideIt = true;

lib/utils/node.js

@@ -176,7 +176,7 @@ function isBlockBody(node, type) {
   if (parentType === 'MemberExpression') {
     return (
       types.includes(
-        parent.callee.object.name + '.' + parent.callee.property.name
+        parent.callee.object.name + '.' + parent.callee.property.name,
       ) && obj.get(parent, 'arguments.1') === node
     );
   }