util.deprecate(fn, msg[, code])

• fn <Function> 被弃用的函数。

  ¥fn <Function> The function that is being deprecated.

• msg <string> 调用弃用的函数时显示的警告消息。

  ¥msg <string> A warning message to display when the deprecated function is invoked.

• code <string> 弃用代码。有关代码列表，请参见 弃用的 API 列表。

  ¥code <string> A deprecation code. See the list of deprecated APIs for a list of codes.

• 返回：<Function> 弃用的函数被封装以触发警告。

  ¥Returns: <Function> The deprecated function wrapped to emit a warning.

util.deprecate() 方法以标记为已弃用的方式封装 fn（可能是函数或类）。

¥The util.deprecate() method wraps fn (which may be a function or class) in such a way that it is marked as deprecated.

import { deprecate } from 'node:util';

export const obsoleteFunction = deprecate(() => {
  // Do something here.
}, 'obsoleteFunction() is deprecated. Use newShinyFunction() instead.');const { deprecate } = require('node:util');

exports.obsoleteFunction = deprecate(() => {
  // Do something here.
}, 'obsoleteFunction() is deprecated. Use newShinyFunction() instead.');拷贝

当调用时，util.deprecate() 将返回将使用 'warning' 事件触发 DeprecationWarning 的函数。第一次调用返回的函数时，警告将触发并打印到 stderr。触发警告后，将调用封装的函数而不触发警告。

¥When called, util.deprecate() will return a function that will emit a DeprecationWarning using the 'warning' event. The warning will be emitted and printed to stderr the first time the returned function is called. After the warning is emitted, the wrapped function is called without emitting a warning.

如果在多次调用 util.deprecate() 时提供了相同的可选 code，则该 code 只会触发一次警告。

¥If the same optional code is supplied in multiple calls to util.deprecate(), the warning will be emitted only once for that code.

import { deprecate } from 'node:util';

const fn1 = deprecate(
  () => 'a value',
  'deprecation message',
  'DEP0001',
);
const fn2 = deprecate(
  () => 'a  different value',
  'other dep message',
  'DEP0001',
);
fn1(); // Emits a deprecation warning with code DEP0001
fn2(); // Does not emit a deprecation warning because it has the same codeconst { deprecate } = require('node:util');

const fn1 = deprecate(
  function() {
    return 'a value';
  },
  'deprecation message',
  'DEP0001',
);
const fn2 = deprecate(
  function() {
    return 'a  different value';
  },
  'other dep message',
  'DEP0001',
);
fn1(); // Emits a deprecation warning with code DEP0001
fn2(); // Does not emit a deprecation warning because it has the same code拷贝

如果使用 --no-deprecation 或 --no-warnings 命令行标志，或者如果在第一次弃用警告之前将 process.noDeprecation 属性设置为 true，则 util.deprecate() 方法不执行任何操作。

¥If either the --no-deprecation or --no-warnings command-line flags are used, or if the process.noDeprecation property is set to true prior to the first deprecation warning, the util.deprecate() method does nothing.

如果设置了 --trace-deprecation 或 --trace-warnings 命令行标志、或者 process.traceDeprecation 属性设置为 true，则在第一次调用已弃用的函数时会向 stderr 打印警告和堆栈跟踪。

¥If the --trace-deprecation or --trace-warnings command-line flags are set, or the process.traceDeprecation property is set to true, a warning and a stack trace are printed to stderr the first time the deprecated function is called.

如果设置了 --throw-deprecation 命令行标志、或者 process.throwDeprecation 属性设置为 true，则在调用已弃用的函数时将抛出异常。

¥If the --throw-deprecation command-line flag is set, or the process.throwDeprecation property is set to true, then an exception will be thrown when the deprecated function is called.

--throw-deprecation 命令行标志和 process.throwDeprecation 属性优先于 --trace-deprecation 和 process.traceDeprecation。

¥The --throw-deprecation command-line flag and process.throwDeprecation property take precedence over --trace-deprecation and process.traceDeprecation.