Jasmine JavaScript Testing Framework Jasmine Matchers and Expectations 2

Question 1

Which Jasmine matcher checks that a string or value matches a regular expression?

Accepted Answer

toMatch(regex)

Answer

toMatch() accepts a RegExp or string pattern and tests the actual value against it.

Question 2

What does toBeNull() specifically check?

Accepted Answer

That the value is strictly null

Answer

toBeNull() uses === null, so it passes only for null and not for undefined or other falsy values.

Question 3

Which Jasmine matcher asserts that a number exceeds another number?

Accepted Answer

toBeGreaterThan(n)

Answer

toBeGreaterThan(n) passes when the actual value is strictly greater than n using the > operator.

Question 4

What role does jasmine.objectContaining({key: value}) play in an expectation?

Accepted Answer

Partially matches an object that has at least those key-value pairs

Answer

objectContaining is an asymmetric matcher that passes if the actual object includes the listed properties, ignoring extras.

Question 5

Which matcher verifies that a function throws an error whose message matches the given string or regex?

Accepted Answer

toThrowError(messageOrRegex)

Answer

toThrowError() can accept a string or regex to match against the thrown error's message property.

Jasmine JavaScript Testing Framework Practice Test