avoid instanceof where it's possible since .prototype and `@@hasI…

…nstance` can be replaced

.eslintrc.js

@@ -225,7 +225,7 @@ const base = {
   'linebreak-style': [ERROR, 'unix'],
   // specify the maximum length of a line in your program
   'max-len': [ERROR, {
-    code: 120,
+    code: 140,
     tabWidth: 2,
     ignoreRegExpLiterals: true,
     ignoreTemplateLiterals: true,

packages/core-js-pure/override/internals/collection.js

@@ -34,19 +34,21 @@ module.exports = function (CONSTRUCTOR_NAME, wrapper, common) {
     InternalMetadataModule.enable();
   } else {
     Constructor = wrapper(function (target, iterable) {
-      setInternalState(anInstance(target, Constructor, CONSTRUCTOR_NAME), {
+      setInternalState(anInstance(target, Prototype), {
         type: CONSTRUCTOR_NAME,
         collection: new NativeConstructor()
       });
       if (iterable != undefined) iterate(iterable, target[ADDER], { that: target, AS_ENTRIES: IS_MAP });
     });
 
+    var Prototype = Constructor.prototype;
+
     var getInternalState = internalStateGetterFor(CONSTRUCTOR_NAME);
 
     forEach(['add', 'clear', 'delete', 'forEach', 'get', 'has', 'set', 'keys', 'values', 'entries'], function (KEY) {
       var IS_ADDER = KEY == 'add' || KEY == 'set';
       if (KEY in NativePrototype && !(IS_WEAK && KEY == 'clear')) {
-        createNonEnumerableProperty(Constructor.prototype, KEY, function (a, b) {
+        createNonEnumerableProperty(Prototype, KEY, function (a, b) {
           var collection = getInternalState(this).collection;
           if (!IS_ADDER && IS_WEAK && !isObject(a)) return KEY == 'get' ? undefined : false;
           var result = collection[KEY](a === 0 ? 0 : a, b);
@@ -55,7 +57,7 @@ module.exports = function (CONSTRUCTOR_NAME, wrapper, common) {
       }
     });
 
-    IS_WEAK || defineProperty(Constructor.prototype, 'size', {
+    IS_WEAK || defineProperty(Prototype, 'size', {
       configurable: true,
       get: function () {
         return getInternalState(this).collection.size;

packages/core-js-pure/override/internals/export.js

@@ -12,7 +12,7 @@ var hasOwn = require('../internals/has-own-property');
 
 var wrapConstructor = function (NativeConstructor) {
   var Wrapper = function (a, b, c) {
-    if (this instanceof NativeConstructor) {
+    if (this instanceof Wrapper) {
       switch (arguments.length) {
         case 0: return new NativeConstructor();
         case 1: return new NativeConstructor(a);

packages/core-js/es/instance/at.js

@@ -1,13 +1,14 @@
-var arrayAt = require('../array/virtual/at');
-var stringAt = require('../string/virtual/at');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var arrayMethod = require('../array/virtual/at');
+var stringMethod = require('../string/virtual/at');
 
 var ArrayPrototype = Array.prototype;
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.at;
-  if (it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.at)) return arrayAt;
-  if (typeof it == 'string' || it === StringPrototype || (it instanceof String && own === StringPrototype.at)) {
-    return stringAt;
+  if (it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.at)) return arrayMethod;
+  if (typeof it == 'string' || it === StringPrototype || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.at)) {
+    return stringMethod;
   } return own;
 };

packages/core-js/es/instance/bind.js

@@ -1,8 +1,9 @@
-var bind = require('../function/virtual/bind');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../function/virtual/bind');
 
 var FunctionPrototype = Function.prototype;
 
 module.exports = function (it) {
   var own = it.bind;
-  return it === FunctionPrototype || (it instanceof Function && own === FunctionPrototype.bind) ? bind : own;
+  return it === FunctionPrototype || (isPrototypeOf(FunctionPrototype, it) && own === FunctionPrototype.bind) ? method : own;
 };

packages/core-js/es/instance/code-point-at.js

@@ -1,9 +1,10 @@
-var codePointAt = require('../string/virtual/code-point-at');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../string/virtual/code-point-at');
 
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.codePointAt;
   return typeof it == 'string' || it === StringPrototype
-    || (it instanceof String && own === StringPrototype.codePointAt) ? codePointAt : own;
+    || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.codePointAt) ? method : own;
 };

packages/core-js/es/instance/concat.js

@@ -1,8 +1,9 @@
-var concat = require('../array/virtual/concat');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/concat');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.concat;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.concat) ? concat : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.concat) ? method : own;
 };

packages/core-js/es/instance/copy-within.js

@@ -1,8 +1,9 @@
-var copyWithin = require('../array/virtual/copy-within');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/copy-within');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.copyWithin;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.copyWithin) ? copyWithin : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.copyWithin) ? method : own;
 };

packages/core-js/es/instance/ends-with.js

@@ -1,9 +1,10 @@
-var endsWith = require('../string/virtual/ends-with');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../string/virtual/ends-with');
 
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.endsWith;
   return typeof it == 'string' || it === StringPrototype
-    || (it instanceof String && own === StringPrototype.endsWith) ? endsWith : own;
+    || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.endsWith) ? method : own;
 };

packages/core-js/es/instance/entries.js

@@ -1,8 +1,9 @@
-var entries = require('../array/virtual/entries');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/entries');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.entries;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.entries) ? entries : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.entries) ? method : own;
 };

packages/core-js/es/instance/every.js

@@ -1,8 +1,9 @@
-var every = require('../array/virtual/every');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/every');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.every;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.every) ? every : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.every) ? method : own;
 };

packages/core-js/es/instance/fill.js

@@ -1,8 +1,9 @@
-var fill = require('../array/virtual/fill');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/fill');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.fill;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.fill) ? fill : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.fill) ? method : own;
 };

packages/core-js/es/instance/filter.js

@@ -1,8 +1,9 @@
-var filter = require('../array/virtual/filter');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/filter');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.filter;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.filter) ? filter : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.filter) ? method : own;
 };

packages/core-js/es/instance/find-index.js

@@ -1,8 +1,9 @@
-var findIndex = require('../array/virtual/find-index');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/find-index');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.findIndex;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.findIndex) ? findIndex : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.findIndex) ? method : own;
 };

packages/core-js/es/instance/find.js

@@ -1,8 +1,9 @@
-var find = require('../array/virtual/find');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/find');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.find;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.find) ? find : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.find) ? method : own;
 };

packages/core-js/es/instance/flags.js

@@ -1,7 +1,8 @@
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
 var flags = require('../regexp/flags');
 
 var RegExpPrototype = RegExp.prototype;
 
 module.exports = function (it) {
-  return (it === RegExpPrototype || it instanceof RegExp) && !('flags' in it) ? flags(it) : it.flags;
+  return (it === RegExpPrototype || isPrototypeOf(RegExpPrototype, it)) ? flags(it) : it.flags;
 };

packages/core-js/es/instance/flat-map.js

@@ -1,8 +1,9 @@
-var flatMap = require('../array/virtual/flat-map');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/flat-map');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.flatMap;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.flatMap) ? flatMap : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.flatMap) ? method : own;
 };

packages/core-js/es/instance/flat.js

@@ -1,8 +1,9 @@
-var flat = require('../array/virtual/flat');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/flat');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.flat;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.flat) ? flat : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.flat) ? method : own;
 };

packages/core-js/es/instance/for-each.js

@@ -1,8 +1,9 @@
-var forEach = require('../array/virtual/for-each');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/for-each');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.forEach;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.forEach) ? forEach : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.forEach) ? method : own;
 };

packages/core-js/es/instance/includes.js

@@ -1,13 +1,14 @@
-var arrayIncludes = require('../array/virtual/includes');
-var stringIncludes = require('../string/virtual/includes');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var arrayMethod = require('../array/virtual/includes');
+var stringMethod = require('../string/virtual/includes');
 
 var ArrayPrototype = Array.prototype;
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.includes;
-  if (it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.includes)) return arrayIncludes;
-  if (typeof it == 'string' || it === StringPrototype || (it instanceof String && own === StringPrototype.includes)) {
-    return stringIncludes;
+  if (it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.includes)) return arrayMethod;
+  if (typeof it == 'string' || it === StringPrototype || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.includes)) {
+    return stringMethod;
   } return own;
 };

packages/core-js/es/instance/index-of.js

@@ -1,8 +1,9 @@
-var indexOf = require('../array/virtual/index-of');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/index-of');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.indexOf;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.indexOf) ? indexOf : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.indexOf) ? method : own;
 };

packages/core-js/es/instance/keys.js

@@ -1,8 +1,9 @@
-var keys = require('../array/virtual/keys');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/keys');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.keys;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.keys) ? keys : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.keys) ? method : own;
 };

packages/core-js/es/instance/last-index-of.js

@@ -1,8 +1,9 @@
-var lastIndexOf = require('../array/virtual/last-index-of');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/last-index-of');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.lastIndexOf;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.lastIndexOf) ? lastIndexOf : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.lastIndexOf) ? method : own;
 };

packages/core-js/es/instance/map.js

@@ -1,8 +1,9 @@
-var map = require('../array/virtual/map');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/map');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.map;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.map) ? map : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.map) ? method : own;
 };

packages/core-js/es/instance/match-all.js

@@ -1,9 +1,10 @@
-var matchAll = require('../string/virtual/match-all');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../string/virtual/match-all');
 
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.matchAll;
   return typeof it == 'string' || it === StringPrototype
-    || (it instanceof String && own === StringPrototype.matchAll) ? matchAll : own;
+    || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.matchAll) ? method : own;
 };

packages/core-js/es/instance/pad-end.js

@@ -1,9 +1,10 @@
-var padEnd = require('../string/virtual/pad-end');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../string/virtual/pad-end');
 
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.padEnd;
   return typeof it == 'string' || it === StringPrototype
-    || (it instanceof String && own === StringPrototype.padEnd) ? padEnd : own;
+    || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.padEnd) ? method : own;
 };

packages/core-js/es/instance/pad-start.js

@@ -1,9 +1,10 @@
-var padStart = require('../string/virtual/pad-start');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../string/virtual/pad-start');
 
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.padStart;
   return typeof it == 'string' || it === StringPrototype
-    || (it instanceof String && own === StringPrototype.padStart) ? padStart : own;
+    || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.padStart) ? method : own;
 };

packages/core-js/es/instance/reduce-right.js

@@ -1,8 +1,9 @@
-var reduceRight = require('../array/virtual/reduce-right');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/reduce-right');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.reduceRight;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.reduceRight) ? reduceRight : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.reduceRight) ? method : own;
 };

packages/core-js/es/instance/reduce.js

@@ -1,8 +1,9 @@
-var reduce = require('../array/virtual/reduce');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../array/virtual/reduce');
 
 var ArrayPrototype = Array.prototype;
 
 module.exports = function (it) {
   var own = it.reduce;
-  return it === ArrayPrototype || (it instanceof Array && own === ArrayPrototype.reduce) ? reduce : own;
+  return it === ArrayPrototype || (isPrototypeOf(ArrayPrototype, it) && own === ArrayPrototype.reduce) ? method : own;
 };

packages/core-js/es/instance/repeat.js

@@ -1,9 +1,10 @@
-var repeat = require('../string/virtual/repeat');
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var method = require('../string/virtual/repeat');
 
 var StringPrototype = String.prototype;
 
 module.exports = function (it) {
   var own = it.repeat;
   return typeof it == 'string' || it === StringPrototype
-    || (it instanceof String && own === StringPrototype.repeat) ? repeat : own;
+    || (isPrototypeOf(StringPrototype, it) && own === StringPrototype.repeat) ? method : own;
 };