Jasmine JavaScript Testing Framework Jasmine Custom Matchers and Extensions 3

Question 1

What is the key difference between jasmine.arrayContaining() and jasmine.arrayWithExactContents()?

Accepted Answer

arrayContaining allows extra elements; arrayWithExactContents requires all elements to match exactly

Answer

arrayContaining checks order; arrayWithExactContents ignores order

Answer

arrayContaining is for objects; arrayWithExactContents is for primitives

Answer

They are identical in behavior

Question 2

How do you define an asymmetric equality tester (custom asymmetric matcher class) in Jasmine?

Accepted Answer

Create a class or object with an asymmetricMatch method

Answer

Call jasmine.addAsymmetricMatcher() with a function

Answer

Extend the JasmineMatcher base class

Answer

Use jasmine.createSpy() with a custom comparator

Question 3

When jasmine.addMatchers() is called and a custom matcher shares a name with a built-in Jasmine matcher, what happens?

Accepted Answer

The custom matcher overrides the built-in matcher for that scope

Answer

Jasmine throws an error and stops execution

Answer

The built-in matcher takes precedence

Answer

Both matchers run and results are ANDed together

Question 4

What does jasmine.addAsyncMatchers() enable compared to jasmine.addMatchers()?

Accepted Answer

Registers matchers whose compare function returns a Promise

Answer

Registers matchers for use in async/await specs only

Answer

Registers matchers that auto-retry on failure

Answer

Registers matchers that can be chained

Question 5

What is the role of the customTesters array that can be passed to matchersUtil.equals()?

Accepted Answer

Allows you to inject custom equality functions that override default object comparison

Answer

Provides a list of matchers to disable

Answer

Specifies which properties to ignore during comparison

Answer

Lists the spies to include in equality checks

Question 6

How should the message property be structured in a custom matcher result object to provide context-sensitive failure output?

Accepted Answer

As a function that returns a string, so Jasmine evaluates it only when needed

Answer

As a static string set at matcher registration time

Answer

As an array of possible messages

Answer

As a template literal with embedded expressions

Question 7

Which Jasmine method would you use to verify that a value satisfies a custom asymmetric matcher when it is used as an expected argument inside toHaveBeenCalledWith()?

Accepted Answer

Pass the asymmetric matcher instance directly as the expected argument to toHaveBeenCalledWith()

Answer

Wrap it with jasmine.matcherFor()

Answer

Call jasmine.expect() with the asymmetric matcher

Answer

Register the matcher with jasmine.addSpyMatcher()