node/test/parallel/test-assert-checktag.js

'use strict';
const { hasCrypto } = require('../common');
const { test } = require('node:test');
const assert = require('assert');

// Turn off no-restricted-properties because we are testing deepEqual!
/* eslint-disable no-restricted-properties */

// Disable colored output to prevent color codes from breaking assertion
// message comparisons. This should only be an issue when process.stdout
// is a TTY.
if (process.stdout.isTTY)
  process.env.NODE_DISABLE_COLORS = '1';

test('', { skip: !hasCrypto }, () => {
  // See https://github.com/nodejs/node/issues/10258
  {
    const date = new Date('2016');
    function FakeDate() {}
    FakeDate.prototype = Date.prototype;
    const fake = new FakeDate();

    assert.notDeepEqual(date, fake);
    assert.notDeepEqual(fake, date);

    // For deepStrictEqual we check the runtime type,
    // then reveal the fakeness of the fake date
    assert.throws(
      () => assert.deepStrictEqual(date, fake),
      {
        message: 'Expected values to be strictly deep-equal:\n' +
        '+ actual - expected\n' +
        '\n' +
        '+ 2016-01-01T00:00:00.000Z\n' +
        '- Date {}\n'
      }
    );
    assert.throws(
      () => assert.deepStrictEqual(fake, date),
      {
        message: 'Expected values to be strictly deep-equal:\n' +
        '+ actual - expected\n' +
        '\n' +
        '+ Date {}\n' +
        '- 2016-01-01T00:00:00.000Z\n'
      }
    );
  }

  {  // At the moment global has its own type tag
    const fakeGlobal = {};
    Object.setPrototypeOf(fakeGlobal, Object.getPrototypeOf(global));
    for (const prop of Object.keys(global)) {
      fakeGlobal[prop] = global[prop];
    }
    assert.notDeepEqual(fakeGlobal, global);
    // Message will be truncated anyway, don't validate
    assert.throws(() => assert.deepStrictEqual(fakeGlobal, global),
                  assert.AssertionError);
  }

  { // At the moment process has its own type tag
    const fakeProcess = {};
    Object.setPrototypeOf(fakeProcess, Object.getPrototypeOf(process));
    for (const prop of Object.keys(process)) {
      fakeProcess[prop] = process[prop];
    }
    assert.notDeepEqual(fakeProcess, process);
    // Message will be truncated anyway, don't validate
    assert.throws(() => assert.deepStrictEqual(fakeProcess, process),
                  assert.AssertionError);
  }
});
/* eslint-enable */