Jasmine JavaScript Testing Framework Jasmine Matchers and Expectations 3

Question 1

What does jasmine.arrayContaining([3, 5]) verify about the actual array?

Accepted Answer

The actual array contains at least 3 and 5 (possibly more)

Answer

arrayContaining is an asymmetric matcher that passes when all listed elements appear in the actual array in any order.

Question 2

Which Jasmine matcher checks that a number is less than or equal to another?

Accepted Answer

toBeLessThanOrEqualTo(n)

Answer

toBeLessThanOrEqualTo(n) uses <= and is the counterpart to toBeGreaterThanOrEqualTo(n).

Question 3

What does toBeInstanceOf(ClassName) verify?

Accepted Answer

That the actual value was created with the given constructor

Answer

toBeInstanceOf() uses the instanceof operator to verify the actual value was constructed by the given class.

Question 4

How do you add a custom matcher available in all specs of a suite?

Accepted Answer

jasmine.addMatchers({matcherName: factory})

Answer

addMatchers() in beforeEach() registers custom matchers whose factory returns compare and negativeCompare methods.

Question 5

What does jasmine.stringMatching(regex) do when used as an asymmetric matcher?

Accepted Answer

Matches any string that satisfies the regex or contains the substring

Answer

stringMatching is an asymmetric matcher that passes when the actual string matches the given regex or contains the given substring.

Jasmine JavaScript Testing Framework Practice Test