process.emitWarning(warning[, type[, code]][, ctor])

• warning <string> | <Error> 要触发的警告。

  ¥warning <string> | <Error> The warning to emit.

• type <string> 当 warning 是 String 时，type 是用于触发的警告类型的名称。默认值：'Warning'。

  ¥type <string> When warning is a String, type is the name to use for the type of warning being emitted. Default: 'Warning'.

• code <string> 触发的警告实例的唯一标识符。

  ¥code <string> A unique identifier for the warning instance being emitted.

• ctor <Function> 当 warning 为 String 时，ctor 是可选函数，用于限制生成的堆栈跟踪。默认值：process.emitWarning。

  ¥ctor <Function> When warning is a String, ctor is an optional function used to limit the generated stack trace. Default: process.emitWarning.

process.emitWarning() 方法可用于触发自定义或特定于应用的进程警告。这些可以通过向 'warning' 事件添加句柄来监听。

¥The process.emitWarning() method can be used to emit custom or application specific process warnings. These can be listened for by adding a handler to the 'warning' event.

import { emitWarning } from 'node:process';

// Emit a warning using a string.
emitWarning('Something happened!');
// Emits: (node: 56338) Warning: Something happened!const { emitWarning } = require('node:process');

// Emit a warning using a string.
emitWarning('Something happened!');
// Emits: (node: 56338) Warning: Something happened!拷贝

import { emitWarning } from 'node:process';

// Emit a warning using a string and a type.
emitWarning('Something Happened!', 'CustomWarning');
// Emits: (node:56338) CustomWarning: Something Happened!const { emitWarning } = require('node:process');

// Emit a warning using a string and a type.
emitWarning('Something Happened!', 'CustomWarning');
// Emits: (node:56338) CustomWarning: Something Happened!拷贝

import { emitWarning } from 'node:process';

emitWarning('Something happened!', 'CustomWarning', 'WARN001');
// Emits: (node:56338) [WARN001] CustomWarning: Something happened!const { emitWarning } = require('node:process');

process.emitWarning('Something happened!', 'CustomWarning', 'WARN001');
// Emits: (node:56338) [WARN001] CustomWarning: Something happened!拷贝

在前面的每个示例中，Error 对象由 process.emitWarning() 在内部生成并传给 'warning' 句柄。

¥In each of the previous examples, an Error object is generated internally by process.emitWarning() and passed through to the 'warning' handler.

import process from 'node:process';

process.on('warning', (warning) => {
  console.warn(warning.name);
  console.warn(warning.message);
  console.warn(warning.code);
  console.warn(warning.stack);
});const process = require('node:process');

process.on('warning', (warning) => {
  console.warn(warning.name);
  console.warn(warning.message);
  console.warn(warning.code);
  console.warn(warning.stack);
});拷贝

如果 warning 作为 Error 对象传入，则它将被不加修改地传给 'warning' 事件句柄（并且可选的 type、code 和 ctor 参数将被忽略）：

¥If warning is passed as an Error object, it will be passed through to the 'warning' event handler unmodified (and the optional type, code and ctor arguments will be ignored):

import { emitWarning } from 'node:process';

// Emit a warning using an Error object.
const myWarning = new Error('Something happened!');
// Use the Error name property to specify the type name
myWarning.name = 'CustomWarning';
myWarning.code = 'WARN001';

emitWarning(myWarning);
// Emits: (node:56338) [WARN001] CustomWarning: Something happened!const { emitWarning } = require('node:process');

// Emit a warning using an Error object.
const myWarning = new Error('Something happened!');
// Use the Error name property to specify the type name
myWarning.name = 'CustomWarning';
myWarning.code = 'WARN001';

emitWarning(myWarning);
// Emits: (node:56338) [WARN001] CustomWarning: Something happened!拷贝

如果 warning 不是字符串或 Error 对象，则抛出 TypeError。

¥A TypeError is thrown if warning is anything other than a string or Error object.

虽然进程警告使用 Error 对象，但进程警告机制并不能替代正常的错误处理机制。

¥While process warnings use Error objects, the process warning mechanism is not a replacement for normal error handling mechanisms.

如果警告 type 为 'DeprecationWarning'，则执行以下额外处理：

¥The following additional handling is implemented if the warning type is 'DeprecationWarning':

• 如果使用 --throw-deprecation 命令行标志，则弃用警告将作为异常抛出，而不是作为事件触发。

  ¥If the --throw-deprecation command-line flag is used, the deprecation warning is thrown as an exception rather than being emitted as an event.

• 如果使用 --no-deprecation 命令行标志，则会取消弃用警告。

  ¥If the --no-deprecation command-line flag is used, the deprecation warning is suppressed.

• 如果使用 --trace-deprecation 命令行标志，则弃用警告将与完整堆栈跟踪一起打印到 stderr。

  ¥If the --trace-deprecation command-line flag is used, the deprecation warning is printed to stderr along with the full stack trace.