Unit Testing & Testability

Question 1

What is unit testing?

Answer 1

Ensuring the functionality of each component works in isolation

Question 2

Unit testing is not about how well things ________ with each other

Answer 2

interact

Question 3

Describe the automated testing pyramid

Answer 3

It’s a 3 level pyramid. The bottom row is unit testing, the middle row is API/integration/component testing, and the top row is System & UI testing

Question 4

In the automated testing pyramid, lower levels are __________ and quick to test, while upper levels are __________ and slower to test

Answer 4

isolated, integrated

Question 5

In practice, there is a debate between how _______ a unit test should be and ____ and _______ testing methodologies

Answer 5

isolated, big, small

Question 6

Another view of unit tests is that they specify the expected ________ of individual components

Answer 6

behavior

Question 7

What is test driven development?

Answer 7

Building unit tests first, then using them to guide development

Question 8

In practice, ______ _________ development has fallen out of favour due to the nature of agile development methods, which includes ever changing requirements

Answer 8

test driven

Question 9

What are 3 guiding principles on writing unit tests?

Answer 9

• Focus on one component in isolation
• Be simple to set up and run
• Be easy to understand

Question 10

In GoogleTest, what is the difference between ASSERT and EXPECT oracles?

Answer 10

ASSERT oracles terminate the program when the fail, which EXPECT oracles allow the program to continue running

Question 11

If you have many tests the require a common set up and tear down routine, consider grouping them in a ______. What do they do?

Answer 11

fixture. Fixtures enable using the same configuration for multiple tests

Question 12

What are the 3 steps usually occurring in a unit test? This is also known as AAA, which stands for what?

Answer 12

1. Set up a scenario
2. Run the scenario
3. Check the outcome
   AAA stands for Arrange, Act, and Assert

Question 13

Two test cases modifying the same DB violates _______ because why?

Answer 13

isolation. The order of the test can affect the results

Question 14

__________ __________ allows the use of mocks and stubs as necessary

Answer 14

Dependency injections

Question 15

When checking pre and post conditions, you check the ________ state as well as the final state

Answer 15

initial

Question 16

What are you checking when using a relative effects pattern of unit testing?

Answer 16

The final state relative to the initial state

Question 17

You can use ______ to check interactions and behaviors

Answer 17

mocks

Question 18

What are some factors that make writing tests hard? (5)

Answer 18

• Connections between classes
• Singletons
• Nondeterminism
• Static Binding
• Mixing construction and application logic

Question 19

What can mocks and stubs offer us in relation to the components we are testing?

Answer 19

They can offer us isolation

Question 20

Using dependency injections with mocks/stubs can lead to a lot of ___________ code

Answer 20

boilerplate code

Question 21

To mitigate boilerplate code when testing, we can use ________ ________

Answer 21

testing frameworks

Question 22

To remove boilerplate code from mocking, what frameworks exist?

Answer 22

GoogleMock, Mockito, etc

Question 23

To remove boilerplate code from dependency injections, what frameworks exist?

Answer 23

Google Guice, Pico Container

Question 24

_____ are more useful when your testing your own component

Answer 24

mocks

Question 25

_____ are more useful when testing external components outside of your control

Answer 25

stub

Question 26

Testing small components raises confidence in the system by raising confidence in it’s ________

Answer 26

constituents