review eslint core rules: enable some rules for parameters

Author: zloirock

packages/core-js-compat/compat.js

@@ -25,7 +25,7 @@ function getModules(filter) {
 
 function normalizeModules(option) {
   // TODO: use `.flatMap` in core-js@4
-  return new Set(Array.isArray(option) ? [].concat.apply([], option.map(getModules)) : getModules(option));
+  return new Set(Array.isArray(option) ? [].concat(...option.map(getModules)) : getModules(option));
 }
 
 function checkModule(name, targets) {

tests/eslint/eslint.config.js

@@ -124,6 +124,8 @@ const base = {
   camelcase: [ERROR, { properties: NEVER }],
   // enforce default clauses in switch statements to be last
   'default-case-last': ERROR,
+  // enforce default parameters to be last
+  'default-param-last': ERROR,
   // encourages use of dot notation whenever possible
   'dot-notation': [ERROR, { allowKeywords: true }],
   // require the use of === and !==
@@ -262,6 +264,10 @@ const base = {
   'prefer-exponentiation-operator': ERROR,
   // prefer `Object.hasOwn`
   'prefer-object-has-own': ERROR,
+  // require rest parameters instead of `arguments`
+  'prefer-rest-params': ERROR,
+  // require spread operators instead of `.apply()`
+  'prefer-spread': ERROR,
   // require template literals instead of string concatenation
   'prefer-template': ERROR,
   // require or disallow use of quotes around object literal property names
@@ -767,6 +773,10 @@ const es3 = {
   'prefer-exponentiation-operator': OFF,
   // prefer `Object.hasOwn`
   'prefer-object-has-own': OFF,
+  // require rest parameters instead of `arguments`
+  'prefer-rest-params': OFF,
+  // require spread operators instead of `.apply()`
+  'prefer-spread': OFF,
   // require template literals instead of string concatenation
   'prefer-template': OFF,
   // require or disallow use of quotes around object literal property names

tests/helpers/helpers.js

@@ -139,8 +139,8 @@ export function patchRegExp$exec(run) {
   return assert => {
     const originalExec = RegExp.prototype.exec;
     // eslint-disable-next-line no-extend-native -- required for testing
-    RegExp.prototype.exec = function () {
-      return originalExec.apply(this, arguments);
+    RegExp.prototype.exec = function (...args) {
+      return originalExec.apply(this, args);
     };
     try {
       return run(assert);

tests/helpers/qunit-helpers.js

@@ -33,7 +33,7 @@ assign(QUnit.assert, {
         : 'Enumerability is not applicable',
     });
   },
-  epsilon(a, b, EPSILON = 1e-11, message) {
+  epsilon(a, b, EPSILON = 1e-11, message = null) {
     const result = Math.abs(a - b) <= EPSILON;
     this.pushResult({
       result,

tests/unit-global/es.array.from.js

@@ -1,3 +1,4 @@
+/* eslint-disable prefer-rest-params -- required for testing */
 import { DESCRIPTORS, GLOBAL } from '../helpers/constants';
 import { createIterable } from '../helpers/helpers';
 

tests/unit-global/es.array.is-array.js

@@ -7,6 +7,7 @@ QUnit.test('Array.isArray', assert => {
   assert.nonEnumerable(Array, 'isArray');
   assert.false(isArray({}));
   assert.false(isArray(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.true(isArray([]));

tests/unit-global/es.object.to-string.js

@@ -20,6 +20,7 @@ QUnit.test('Object#toString', assert => {
   assert.same(toString.call(/./), '[object RegExp]', 'regexp -> `RegExp`');
   assert.same(toString.call(new TypeError()), '[object Error]', 'new TypeError -> `Error`');
   assert.same(toString.call(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()), '[object Arguments]', 'arguments -> `Arguments`');
   const constructors = [

tests/unit-global/es.regexp.test.js

@@ -1,8 +1,8 @@
 
 QUnit.test('RegExp#test delegates to exec', assert => {
-  const exec = function () {
+  const exec = function (...args) {
     execCalled = true;
-    return /./.exec.apply(this, arguments);
+    return /./.exec.apply(this, args);
   };
 
   let execCalled = false;

tests/unit-global/es.string.from-code-point.js

@@ -1,3 +1,4 @@
+/* eslint-disable prefer-spread -- required for testing */
 QUnit.test('String.fromCodePoint', assert => {
   const { fromCodePoint } = String;
   assert.isFunction(fromCodePoint);

tests/unit-global/es.string.match.js

@@ -228,9 +228,9 @@ QUnit.test('String#match delegates to @@match', assert => {
 });
 
 QUnit.test('RegExp#@@match delegates to exec', assert => {
-  const exec = function () {
+  const exec = function (...args) {
     execCalled = true;
-    return /./.exec.apply(this, arguments);
+    return /./.exec.apply(this, args);
   };
 
   let execCalled = false;

tests/unit-global/es.string.replace.js

@@ -170,9 +170,9 @@ QUnit.test('String.replace delegates to @@replace', assert => {
 });
 
 QUnit.test('RegExp#@@replace delegates to exec', assert => {
-  const exec = function () {
+  const exec = function (...args) {
     execCalled = true;
-    return /./.exec.apply(this, arguments);
+    return /./.exec.apply(this, args);
   };
 
   let execCalled = false;

tests/unit-global/es.string.search.js

@@ -112,9 +112,9 @@ QUnit.test('RegExp#@@search delegates to exec', assert => {
   let execCalled = false;
   let re = /b/;
   re.lastIndex = 7;
-  re.exec = function () {
+  re.exec = function (...args) {
     execCalled = true;
-    return /./.exec.apply(this, arguments);
+    return /./.exec.apply(this, args);
   };
   assert.deepEqual(re[Symbol.search]('abc'), 1);
   assert.true(execCalled);

tests/unit-global/es.string.split.js

@@ -735,18 +735,19 @@ QUnit.test('RegExp#@@split delegates to exec', assert => {
   let speciesCalled = false;
   let execSpeciesCalled = false;
   const re = /[24]/;
-  re.exec = function () {
+  re.exec = function (...args) {
     execCalled = true;
-    return /./.exec.apply(this, arguments);
+    return /./.exec.apply(this, args);
   };
   re.constructor = {
     // eslint-disable-next-line object-shorthand -- constructor
-    [Symbol.species]: function (source, flags) {
+    [Symbol.species]: function (...args) {
+      const [source, flags] = args;
       const re2 = new RegExp(source, flags);
       speciesCalled = true;
       re2.exec = function () {
         execSpeciesCalled = true;
-        return /./.exec.apply(this, arguments);
+        return /./.exec.apply(this, args);
       };
       return re2;
     },

tests/unit-global/esnext.array.is-template-object.js

@@ -12,6 +12,7 @@ QUnit.test('Array.isTemplateObject', assert => {
   assert.false(isTemplateObject(null));
   assert.false(isTemplateObject({}));
   assert.false(isTemplateObject(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.false(isTemplateObject([]));

tests/unit-global/esnext.function.is-callable.js

@@ -9,6 +9,7 @@ QUnit.test('Function.isCallable', assert => {
   assert.nonEnumerable(Function, 'isCallable');
   assert.false(isCallable({}), 'object');
   assert.false(isCallable(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()), 'arguments');
   assert.false(isCallable([]), 'array');

tests/unit-global/esnext.function.is-constructor.js

@@ -9,6 +9,7 @@ QUnit.test('Function.isConstructor', assert => {
   assert.nonEnumerable(Function, 'isConstructor');
   assert.false(isConstructor({}), 'object');
   assert.false(isConstructor(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()), 'arguments');
   assert.false(isConstructor([]), 'array');

tests/unit-pure/es.array.from.js

@@ -1,3 +1,4 @@
+/* eslint-disable prefer-rest-params -- required for testing */
 import { DESCRIPTORS } from '../helpers/constants';
 import { createIterable } from '../helpers/helpers';
 

tests/unit-pure/es.array.is-array.js

@@ -4,6 +4,7 @@ QUnit.test('Array.isArray', assert => {
   assert.isFunction(isArray);
   assert.false(isArray({}));
   assert.false(isArray(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.true(isArray([]));

tests/unit-pure/es.string.from-code-point.js

@@ -1,3 +1,4 @@
+/* eslint-disable prefer-spread -- required for testing */
 import fromCodePoint from 'core-js-pure/es/string/from-code-point';
 
 QUnit.test('String.fromCodePoint', assert => {

tests/unit-pure/esnext.array.is-template-object.js

@@ -10,6 +10,7 @@ QUnit.test('Array.isTemplateObject', assert => {
   assert.false(isTemplateObject(null));
   assert.false(isTemplateObject({}));
   assert.false(isTemplateObject(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.false(isTemplateObject([]));

tests/unit-pure/esnext.function.is-callable.js

@@ -7,6 +7,7 @@ QUnit.test('Function.isCallable', assert => {
   assert.name(isCallable, 'isCallable');
   assert.false(isCallable({}), 'object');
   assert.false(isCallable(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()), 'arguments');
   assert.false(isCallable([]), 'array');

tests/unit-pure/esnext.function.is-constructor.js

@@ -7,6 +7,7 @@ QUnit.test('Function.isConstructor', assert => {
   assert.name(isConstructor, 'isConstructor');
   assert.false(isConstructor({}), 'object');
   assert.false(isConstructor(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()), 'arguments');
   assert.false(isConstructor([]), 'array');

tests/unit-pure/helpers.get-iterator-method.js

@@ -10,6 +10,7 @@ QUnit.test('getIteratorMethod helper', assert => {
   assert.isIterator(iterFn.call(iterable));
   assert.isFunction(getIteratorMethod([]));
   assert.isFunction(getIteratorMethod(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.isFunction(getIteratorMethod(Array.prototype));

tests/unit-pure/helpers.get-iterator.js

@@ -6,6 +6,7 @@ QUnit.test('getIterator helper', assert => {
   assert.isFunction(getIterator);
   assert.isIterator(getIterator([]));
   assert.isIterator(getIterator(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.isIterator(getIterator(createIterable([])));

tests/unit-pure/helpers.is-iterable.js

@@ -7,6 +7,7 @@ QUnit.test('isIterable helper', assert => {
   assert.true(isIterable(createIterable([])));
   assert.true(isIterable([]));
   assert.true(isIterable(function () {
+    // eslint-disable-next-line prefer-rest-params -- required for testing
     return arguments;
   }()));
   assert.true(isIterable(Array.prototype));