var uncurryThis = require('../internals/function-uncurry-this');
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var fails = require('../internals/fails');
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var isCallable = require('../internals/is-callable');
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var classof = require('../internals/classof');
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var getBuiltIn = require('../internals/get-built-in');
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var inspectSource = require('../internals/inspect-source');
|
|
var noop = function () { /* empty */ };
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var empty = [];
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var construct = getBuiltIn('Reflect', 'construct');
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var constructorRegExp = /^\s*(?:class|function)\b/;
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var exec = uncurryThis(constructorRegExp.exec);
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var INCORRECT_TO_STRING = !constructorRegExp.exec(noop);
|
|
var isConstructorModern = function isConstructor(argument) {
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if (!isCallable(argument)) return false;
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try {
|
construct(noop, empty, argument);
|
return true;
|
} catch (error) {
|
return false;
|
}
|
};
|
|
var isConstructorLegacy = function isConstructor(argument) {
|
if (!isCallable(argument)) return false;
|
switch (classof(argument)) {
|
case 'AsyncFunction':
|
case 'GeneratorFunction':
|
case 'AsyncGeneratorFunction': return false;
|
}
|
try {
|
// we can't check .prototype since constructors produced by .bind haven't it
|
// `Function#toString` throws on some built-it function in some legacy engines
|
// (for example, `DOMQuad` and similar in FF41-)
|
return INCORRECT_TO_STRING || !!exec(constructorRegExp, inspectSource(argument));
|
} catch (error) {
|
return true;
|
}
|
};
|
|
isConstructorLegacy.sham = true;
|
|
// `IsConstructor` abstract operation
|
// https://tc39.es/ecma262/#sec-isconstructor
|
module.exports = !construct || fails(function () {
|
var called;
|
return isConstructorModern(isConstructorModern.call)
|
|| !isConstructorModern(Object)
|
|| !isConstructorModern(function () { called = true; })
|
|| called;
|
}) ? isConstructorLegacy : isConstructorModern;
|
