// Mark that a method should not be used.

// Returns a modified function which warns once by default.

// If --no-deprecation is set, then it is a no-op.

function deprecate(fn, msg, code, useEmitSync) {

function deprecate(fn, msg, code, useEmitSync, modifyPrototype = true) {

// Lazy-load to avoid a circular dependency.

if (validateString === undefined)

({ validateString } = require('internal/validators'));

return ReflectApply(fn, this, args);

}

// The wrapper will keep the same prototype as fn to maintain prototype chain

ObjectSetPrototypeOf(deprecated, fn);

if (fn.prototype) {

// Setting this (rather than using Object.setPrototype, as above) ensures

// that calling the unwrapped constructor gives an instanceof the wrapped

// constructor.

deprecated.prototype = fn.prototype;

}

if (modifyPrototype) {

// The wrapper will keep the same prototype as fn to maintain prototype chain

// Modifying the prototype does alter the object chains, and as observed in

// most cases, it slows the code.

ObjectSetPrototypeOf(deprecated, fn);

if (fn.prototype) {

// Setting this (rather than using Object.setPrototype, as above) ensures

// that calling the unwrapped constructor gives an instanceof the wrapped

// constructor.

deprecated.prototype = fn.prototype;

}

ObjectDefineProperty(deprecated, 'length', {

__proto__: null,

...ObjectGetOwnPropertyDescriptor(fn, 'length'),

});

ObjectDefineProperty(deprecated, 'length', {

__proto__: null,

...ObjectGetOwnPropertyDescriptor(fn, 'length'),

});

}

return deprecated;

}