example.js

// https://github.com/nodejs/node/blob/b476b1b91ef8715f096f815db5a0c8722b613678/doc/api/test.md

"use strict";

const assert = require("assert");
const test = require(".");

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"));
  });
});