基准报告器

🌐 Benchmark reporters

内置报告器可以从仅限 Scheme 的 node:bench/reporters 模块中获取：

🌐 The built-in reporters are available from the scheme-only node:bench/reporters module:

import { json, spec } from 'node:bench/reporters';const { json, spec } = require('node:bench/reporters');拷贝

Reporter 的值可以直接传递给 stream.compose()：

🌐 Reporter values can be passed directly to stream.compose():

import { bench, run } from 'node:bench';
import { spec } from 'node:bench/reporters';
import process from 'node:process';

bench('example', (b) => {
  b.start();
  doWork();
  b.end(1);
});

run().compose(spec).pipe(process.stdout); 拷贝

spec 报告器会缓冲结果，并输出一个简洁的表格，包含样本数量、平均速率、平均值的 95% 置信区间、中位速率以及警告。修改系数超过 5% 会显示为 noisy，绝对偏度超过 1 会显示为 skewed。具体的可读格式可能会有所变化。

🌐 The spec reporter buffers results and outputs a concise table containing the sample count, mean rate, 95% confidence interval for the mean, median rate, and warnings. A coefficient of variation above 5% is reported as noisy, and an absolute skewness above 1 is reported as skewed. The exact human-readable format is subject to change.

json 报告器会将每个生命周期记录作为换行分隔的 JSON 输出。BigInt 值，包括 duration_ns，会被编码为十进制字符串。错误会使用它们的 name、message、stack、code、cause 和 errors 属性表示。根据 JSON 的要求，非有限数字会被编码为 null。

🌐 The json reporter emits every lifecycle record as newline-delimited JSON. BigInt values, including duration_ns, are encoded as decimal strings. Errors are represented using their name, message, stack, code, cause, and errors properties. As required by JSON, non-finite numbers are encoded as null.

自定义报告器使用相同的组合契约。它们可以是 stream.compose() 接受的转换或函数。组合后的可读流可以传输到任意可写的目标：

🌐 Custom reporters use the same composition contract. They can be transforms or functions accepted by stream.compose(). The composed readable can be piped to any writable destination:

import { run } from 'node:bench';
import process from 'node:process';

async function* names(source) {
  for await (const { type, data } of source) {
    if (type === 'bench:complete') {
      yield `${data.name}\n`;
    }
  }
}

run().compose(names).pipe(process.stdout); 拷贝