Node.js Quality Control & Assurance 2

Question 1

Which Node.js built-in module provides the `assert.deepStrictEqual()` method for comparing objects in tests?

Accepted Answer

assert

Answer

The `assert` module provides `deepStrictEqual()` which recursively checks that objects have the same properties and values using strict equality.

Question 2

In Jest, what does the `--coverage` flag generate?

Accepted Answer

A code coverage report showing tested and untested lines

Answer

`--coverage` instruments the code and generates an HTML/text report showing line, branch, function, and statement coverage percentages.

Question 3

What is the purpose of `nock` in Node.js testing?

Accepted Answer

To intercept and mock HTTP requests made by the application

Answer

`nock` intercepts outgoing HTTP requests and returns predefined responses, allowing tests to run without hitting real external services.

Question 4

Which command runs only tests whose names match a pattern in Jest?

Accepted Answer

jest --testNamePattern="pattern"

Answer

`--testNamePattern` (or `-t`) filters tests by matching the pattern against each test's full name including describe blocks.

Question 5

In Mocha, what is the role of the `done` callback passed to an asynchronous test function?

Accepted Answer

It signals Mocha that the async test has completed or failed

Answer

Calling `done()` with no argument signals success; calling `done(err)` with an error fails the test and reports the error.

Node.js Practice Test