test 测试

源代码: lib/test.js

node:test 模块有助于创建以 TAP 格式报告结果的 JavaScript 测试。 要访问它：

import test from 'node:test';const test = require('node:test');

此模块仅在 node: 协议下可用。 以下将不起作用：

import test from 'test';const test = require('test');

通过 test 模块创建的测试由单个函数组成，该函数以三种方式之一进行处理：

1. 同步的函数，如果抛出异常则认为失败，否则认为通过。
2. 返回 Promise 的函数，如果 Promise 拒绝，则认为该函数失败，如果 Promise 解决，则认为该函数通过。
3. 接收回调函数的函数。 如果回调接收到任何真值作为其第一个参数，则认为测试失败。 如果非真值作为第一个参数传给回调，则认为测试通过。 如果测试函数接收到回调函数并且还返回 Promise，则测试将失败。

以下示例说明了如何使用 test 模块编写测试。

test('synchronous passing test', (t) => {
  // 此测试通过了，因为它没有抛出异常。
  assert.strictEqual(1, 1);
});

test('synchronous failing test', (t) => {
  // 此测试失败，因为它抛出了异常。
  assert.strictEqual(1, 2);
});

test('asynchronous passing test', async (t) => {
  // 此测试通过了，
  // 因为异步函数返回的 Promise 没有被拒绝。
  assert.strictEqual(1, 1);
});

test('asynchronous failing test', async (t) => {
  // 此测试失败，
  // 因为异步函数返回的 Promise 被拒绝。
  assert.strictEqual(1, 2);
});

test('failing test using Promises', (t) => {
  // Promise 也可以直接使用。
  return new Promise((resolve, reject) => {
    setImmediate(() => {
      reject(new Error('this will cause the test to fail'));
    });
  });
});

test('callback passing test', (t, done) => {
  // done() 是回调函数。
  // 当 setImmediate() 运行时，它调用 done() 不带参数。
  setImmediate(done);
});

test('callback failing test', (t, done) => {
  // 当 setImmediate() 运行时，
  // 使用 Error 对象调用 done() 并且测试失败。
  setImmediate(() => {
    done(new Error('callback failure'));
  });
});

当测试文件执行时，TAP 被写入 Node.js 进程的标准输出。 此输出可以被任何理解 TAP 格式的测试工具解释。 如果任何测试失败，则进程退出代码设置为 1。

Source Code: lib/test.js

The node:test module facilitates the creation of JavaScript tests that report results in TAP format. To access it:

import test from 'node:test';const test = require('node:test');

This module is only available under the node: scheme. The following will not work:

import test from 'test';const test = require('test');

Tests created via the test module consist of a single function that is processed in one of three ways:

1. A synchronous function that is considered failing if it throws an exception, and is considered passing otherwise.
2. A function that returns a Promise that is considered failing if the Promise rejects, and is considered passing if the Promise resolves.
3. A function that receives a callback function. If the callback receives any truthy value as its first argument, the test is considered failing. If a falsy value is passed as the first argument to the callback, the test is considered passing. If the test function receives a callback function and also returns a Promise, the test will fail.

The following example illustrates how tests are written using the test module.

test('synchronous passing test', (t) => {
  // This test passes because it does not throw an exception.
  assert.strictEqual(1, 1);
});

test('synchronous failing test', (t) => {
  // This test fails because it throws an exception.
  assert.strictEqual(1, 2);
});

test('asynchronous passing test', async (t) => {
  // This test passes because the Promise returned by the async
  // function is not rejected.
  assert.strictEqual(1, 1);
});

test('asynchronous failing test', async (t) => {
  // This test fails because the Promise returned by the async
  // function is rejected.
  assert.strictEqual(1, 2);
});

test('failing test using Promises', (t) => {
  // Promises can be used directly as well.
  return new Promise((resolve, reject) => {
    setImmediate(() => {
      reject(new Error('this will cause the test to fail'));
    });
  });
});

test('callback passing test', (t, done) => {
  // done() is the callback function. When the setImmediate() runs, it invokes
  // done() with no arguments.
  setImmediate(done);
});

test('callback failing test', (t, done) => {
  // When the setImmediate() runs, done() is invoked with an Error object and
  // the test fails.
  setImmediate(() => {
    done(new Error('callback failure'));
  });
});

As a test file executes, TAP is written to the standard output of the Node.js process. This output can be interpreted by any test harness that understands the TAP format. If any tests fail, the process exit code is set to 1.