19 lines
736 B
JavaScript
19 lines
736 B
JavaScript
var isCallable = require('../internals/is-callable');
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var isObject = require('../internals/is-object');
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var setPrototypeOf = require('../internals/object-set-prototype-of');
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// makes subclassing work correct for wrapped built-ins
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module.exports = function ($this, dummy, Wrapper) {
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var NewTarget, NewTargetPrototype;
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if (
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// it can work only with native `setPrototypeOf`
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setPrototypeOf &&
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// we haven't completely correct pre-ES6 way for getting `new.target`, so use this
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isCallable(NewTarget = dummy.constructor) &&
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NewTarget !== Wrapper &&
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isObject(NewTargetPrototype = NewTarget.prototype) &&
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NewTargetPrototype !== Wrapper.prototype
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) setPrototypeOf($this, NewTargetPrototype);
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return $this;
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};
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