Assert module for assertions in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Node.js assert module?

The assert module is used to write tests that check if values meet expected conditions. It helps catch errors by throwing exceptions when assertions fail.

beginner

How do you import the <code>assert</code> module in Node.js?

Use <code>const assert = require('assert');</code> to import the module and use its assertion functions.

beginner

What does assert.strictEqual(actual, expected) do?

It checks if actual and expected are strictly equal (using ===). If not, it throws an error.

beginner

What happens if an assertion fails in Node.js assert module?

An AssertionError is thrown, stopping the program unless caught. This signals a test failure or unexpected condition.

intermediate

Name two assertion methods from the Node.js assert module besides strictEqual.

Examples include assert.ok(value) which checks if value is truthy, and assert.deepStrictEqual(actual, expected) which checks deep equality of objects or arrays.

Which Node.js module is used for simple assertion testing?

A http

B assert

C fs

D events

The assert module provides assertion functions for testing conditions.

What does assert.ok(value) check?

A If value is strictly equal to true

B If value is falsy

C If value is undefined

D If value is truthy

assert.ok(value) passes if value is truthy (not false, 0, '', null, undefined, or NaN).

What error type does the assert module throw on failure?

A AssertionError

B ReferenceError

C TypeError

D SyntaxError

Failed assertions throw an AssertionError.

Which method checks deep equality of objects in assert?

A assert.equal()

B assert.ok()

C assert.deepStrictEqual()

D assert.strictEqual()

assert.deepStrictEqual() compares objects or arrays deeply.

How do you import the assert module in Node.js?

A const assert = require('assert');

B import assert from 'assert';

C require('assert');

D import { assert } from 'node';

The common way is const assert = require('assert'); in Node.js.

Explain how to use the Node.js assert module to check if two values are strictly equal.

Think about how to compare values exactly and catch errors.

Describe what happens when an assertion fails using the Node.js assert module.

Consider what the module does to alert you about wrong conditions.