Jasmine JavaScript Testing Framework Jasmine Custom Matchers and Extensions

Question 1

Which Jasmine method is used to register custom matchers so they are available in specs?

Accepted Answer

jasmine.addMatchers()

Answer

jasmine.addMatchers() accepts an object map of matcher names to factory functions and makes them available inside describe/it blocks.

Question 2

Where should jasmine.addMatchers() typically be called to ensure custom matchers are available for every spec in a suite?

Accepted Answer

Inside a beforeEach block

Answer

Calling jasmine.addMatchers() inside a beforeEach block ensures the custom matchers are registered before each spec runs within that suite.

Question 3

What does jasmine.objectContaining({ name: 'Alice' }) do when used in an expectation?

Accepted Answer

Passes if the actual object has at least a name property equal to 'Alice'

Answer

jasmine.objectContaining() is an asymmetric matcher that passes as long as the specified key-value pairs are present, ignoring any additional properties.

Question 4

What must a custom matcher factory function return?

Accepted Answer

An object with a compare function

Answer

A custom matcher factory returns an object that must include a compare function, which Jasmine calls with the actual and expected values.

Question 5

What does the compare function inside a custom matcher need to return?

Accepted Answer

An object with a pass property (boolean) and optionally a message

Answer

The compare function must return an object with at least { pass: boolean }, and can include a message property for failure descriptions.

Jasmine JavaScript Testing Framework Practice Test

Jasmine JavaScript Testing Framework Practice Test

Jasmine JavaScript Testing Framework Jasmine Custom Matchers and Extensions