Tips, Tricks, and Techniques for Node.js Development 4.4: Code Coverage

The video tutorial explores the use of Istanbul for measuring code coverage. It covers the installation and execution of tests using Istanbul, generating HTML reports, and understanding the limitations of code coverage as a measure of code quality. The tutorial also demonstrates how to exclude certain files from coverage, re-run tests, and improve test coverage by writing effective tests. Additionally, it discusses refactoring code to make it more testable and concludes with a preview of browser automated testing.

What is a common misconception about code coverage?

• It guarantees high code quality.

• It measures the number of tests written.

• It ensures all bugs are fixed.

• It indicates the speed of code execution.

Which tool is used to measure code coverage in the video?

• Mocha

• Jasmine

• Istanbul

• Chrome

What command is used to run tests with coverage using NPM scripts?

• npm start

• npm install

• npm run test

• npm build

What does 100% branch coverage indicate?

• All possible paths through the code are tested.

• All lines of code are executed.

• All functions are called.

• All variables are initialized.

Why might a function not be covered in a test?

• It is written in a different language.

• It is not called in any test.

• It is not part of the main codebase.

• It is too complex to test.

What is a strategy to improve code coverage?

• Use a different programming language.

• Write more tests for uncovered code.

• Delete untested code.

• Ignore coverage reports.

What is the purpose of refactoring code in the context of testing?

• To make it run faster.

• To change its functionality.

• To make it more testable.

• To reduce its size.