Chai quiz

Test your Chai knowledge with a free interactive quiz — 20 questions with answers and explanations. No signup needed to play.

What does `expect(obj).to.be.an.instanceof(MyClass)` check?

1. What does `expect(obj).to.be.an.instanceof(MyClass)` check?
2. What does `expect(number).to.be.above(5)` (or its alias `.gt(5)`) check?
3. What does `expect(array).to.include(value)` check?
4. What is the difference between `expect(value).to.be.null` and `expect(value).to.not.exist`?
5. What is the difference between `.deep.equal()` and `.equal()` when comparing two objects?
6. How do you negate a Chai assertion?
7. What is a key readability advantage often cited for Chai's BDD (`expect`/`should`) style over the TDD (`assert`) style?
8. What does `expect(obj).to.have.property("name", "Ada")` check?
9. What does `expect(string).to.match(/^[a-z]+$/)` check?
10. In the `assert` style, what does `assert.isTrue(value)` do differently from `assert.ok(value)`?
11. What does `expect(value).to.equal(other)` check, and how does it differ from `.to.eql(other)`?
12. What are Chai plugins (like `chai-as-promised` or `sinon-chai`) used for?

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