add Error.isError

packages/core-js-compat/src/data.mjs

@@ -2241,6 +2241,8 @@ export const data = {
     // reverted in https://issues.chromium.org/issues/42203506#comment25
     // chrome: '133',
   },
+  'esnext.error.is-error': {
+  },
   'esnext.function.demethodize': {
   },
   'esnext.function.is-callable': {

packages/core-js-compat/src/modules-by-versions.mjs

@@ -274,4 +274,7 @@ export default {
     'esnext.weak-map.get-or-insert',
     'esnext.weak-map.get-or-insert-computed',
   ],
+  '3.40': [
+    'esnext.error.is-error',
+  ],
 };

packages/core-js/actual/error/index.js

@@ -1,4 +1,6 @@
 'use strict';
 var parent = require('../../stable/error');
+require('../../modules/es.object.create');
+require('../../modules/esnext.error.is-error');
 
 module.exports = parent;

packages/core-js/actual/error/is-error.js

@@ -0,0 +1,6 @@
+'use strict';
+require('../../modules/es.object.create');
+require('../../modules/esnext.error.is-error');
+var path = require('../../internals/path');
+
+module.exports = path.Error.isError;

packages/core-js/full/error/is-error.js

@@ -0,0 +1,4 @@
+'use strict';
+var parent = require('../../actual/error/is-error');
+
+module.exports = parent;

packages/core-js/modules/esnext.error.is-error.js

@@ -0,0 +1,36 @@
+'use strict';
+var $ = require('../internals/export');
+var getBuiltIn = require('../internals/get-built-in');
+var isObject = require('../internals/is-object');
+var classof = require('../internals/classof');
+var fails = require('../internals/fails');
+
+var ERROR = 'Error';
+var DOM_EXCEPTION = 'DOMException';
+// eslint-disable-next-line es/no-object-setprototypeof, no-proto -- safe
+var PROTOTYPE_SETTING_AVAILABLE = Object.setPrototypeOf || ({}).__proto__;
+
+var DOMException = getBuiltIn(DOM_EXCEPTION);
+var $Error = Error;
+var $isError = $Error.isError;
+
+var FORCED = !$isError || !PROTOTYPE_SETTING_AVAILABLE || fails(function () {
+  // Bun, isNativeError-based implementations, some buggy structuredClone-based implementations, etc.
+  // https://github.com/oven-sh/bun/issues/15821
+  return (DOMException && !$isError(new DOMException(DOM_EXCEPTION))) ||
+    // structuredClone-based implementations
+    // eslint-disable-next-line es/no-error-cause -- detection
+    !$isError(new $Error(ERROR, { cause: function () { /* empty */ } })) ||
+    // instanceof-based and FF Error#stack-based implementations
+    $isError(getBuiltIn('Object', 'create')($Error.prototype));
+});
+
+// `Error.isError` method
+// https://github.com/tc39/proposal-is-error
+$({ target: 'Error', stat: true, sham: true, forced: FORCED }, {
+  isError: function isError(arg) {
+    if (!isObject(arg)) return false;
+    var tag = classof(arg);
+    return tag === ERROR || tag === DOM_EXCEPTION;
+  }
+});

packages/core-js/proposals/is-error.js

@@ -0,0 +1,3 @@
+'use strict';
+// https://github.com/tc39/proposal-is-error
+require('../modules/esnext.error.is-error');

packages/core-js/stage/3.js

@@ -6,6 +6,7 @@ require('../proposals/array-from-async-stage-2');
 require('../proposals/decorator-metadata-v2');
 require('../proposals/explicit-resource-management');
 require('../proposals/float16');
+require('../proposals/is-error');
 require('../proposals/json-parse-with-source');
 require('../proposals/math-sum');
 require('../proposals/regexp-escaping');