Mock dependencies in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of mocking dependencies in Flutter testing?

Mocking dependencies allows you to replace real objects with fake ones to isolate the code under test. This helps test components without relying on external services or complex setups.

beginner

Which Flutter package is commonly used for creating mock classes?

The mockito package is commonly used in Flutter to create mock classes for testing purposes.

intermediate

How do you create a mock class using Mockito in Flutter?

You create a mock class by extending <code>Mock</code> and implementing the class you want to mock. For example: <pre>class MockService extends Mock implements Service {}</pre>

beginner

Why should you mock dependencies instead of using real ones in unit tests?

Mocking dependencies makes tests faster, more reliable, and focused on the unit being tested. It avoids side effects like network calls or database access.

intermediate

What is a common method to verify that a mocked method was called in Flutter tests?

You use verify() from Mockito to check if a mocked method was called with expected arguments.

Which package helps you create mock objects in Flutter?

A mockito

B http

C provider

D flutter_test

The mockito package is designed for creating mock objects in Flutter tests.

What is the main benefit of mocking dependencies in tests?

A To make tests slower

B To add UI animations

C To isolate the unit being tested

D To increase network calls

Mocking dependencies isolates the unit under test by replacing real dependencies with fake ones.

How do you verify a mocked method was called in Flutter tests?

A using <code>verify()</code>

B using <code>expect()</code>

C using <code>mock()</code>

D using <code>run()</code>

The verify() function from Mockito checks if a mocked method was called.

Which of these is NOT a reason to mock dependencies?

A Isolate code under test

B Avoid side effects

C Speed up tests

D Test UI animations

Mocking dependencies is not used to test UI animations.

What does this code do?

class MockApi extends Mock implements Api {}

A Creates a real Api instance

B Creates a mock class for Api

C Runs the Api service

D Imports the Api package

This code defines a mock class for Api using Mockito.

Explain why mocking dependencies is important in Flutter unit testing.

Think about how tests behave when they depend on real network or database.

Describe the steps to create and use a mock class with Mockito in Flutter.

Focus on how to define the mock and check its usage.