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RafaelGSSaduh95
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lib: flag to conditionally modify proto on deprecate
Refs: #58218 Signed-off-by: RafaelGSS <rafael.nunu@hotmail.com> PR-URL: #58928 Reviewed-By: Juan JosΓ© Arboleda <soyjuanarbol@gmail.com> Reviewed-By: Ulises GascΓ³n <ulisesgascongonzalez@gmail.com>
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+53
-13
lines changed

2 files changed

+53
-13
lines changed

β€Žbenchmark/util/deprecate.js

Lines changed: 36 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,36 @@
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'use strict';
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const common = require('../common');
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const assert = require('assert');
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const bench = common.createBenchmark(main, {
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n: [1e5],
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modifyPrototype: [1, 0],
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emitWarningSync: [1, 0],
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}, {
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flags: ['--expose-internals'],
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});
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function simpleFunction(x) {
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return x * 2 + (new Array(1000)).fill(0).map((_, i) => i).reduce((a, b) => a + b, 0);
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}
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function main({ n, modifyPrototype, emitWarningSync }) {
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const { deprecate } = require('internal/util');
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const fn = deprecate(
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simpleFunction,
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'This function is deprecated',
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'DEP0000',
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emitWarningSync,
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!!modifyPrototype,
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);
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let sum = 0;
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bench.start();
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for (let i = 0; i < n; ++i) {
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sum += fn(i);
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}
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bench.end(n);
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assert.ok(sum);
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}

β€Žlib/internal/util.js

Lines changed: 17 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -158,7 +158,7 @@ function pendingDeprecate(fn, msg, code) {
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// Mark that a method should not be used.
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// Returns a modified function which warns once by default.
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// If --no-deprecation is set, then it is a no-op.
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function deprecate(fn, msg, code, useEmitSync) {
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function deprecate(fn, msg, code, useEmitSync, modifyPrototype = true) {
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// Lazy-load to avoid a circular dependency.
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if (validateString === undefined)
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({ validateString } = require('internal/validators'));
@@ -181,19 +181,23 @@ function deprecate(fn, msg, code, useEmitSync) {
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return ReflectApply(fn, this, args);
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}
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// The wrapper will keep the same prototype as fn to maintain prototype chain
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ObjectSetPrototypeOf(deprecated, fn);
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if (fn.prototype) {
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// Setting this (rather than using Object.setPrototype, as above) ensures
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// that calling the unwrapped constructor gives an instanceof the wrapped
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// constructor.
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deprecated.prototype = fn.prototype;
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}
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if (modifyPrototype) {
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// The wrapper will keep the same prototype as fn to maintain prototype chain
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// Modifying the prototype does alter the object chains, and as observed in
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// most cases, it slows the code.
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ObjectSetPrototypeOf(deprecated, fn);
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if (fn.prototype) {
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// Setting this (rather than using Object.setPrototype, as above) ensures
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// that calling the unwrapped constructor gives an instanceof the wrapped
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// constructor.
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deprecated.prototype = fn.prototype;
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}
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ObjectDefineProperty(deprecated, 'length', {
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__proto__: null,
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...ObjectGetOwnPropertyDescriptor(fn, 'length'),
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});
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ObjectDefineProperty(deprecated, 'length', {
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__proto__: null,
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...ObjectGetOwnPropertyDescriptor(fn, 'length'),
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});
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}
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return deprecated;
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}

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