Learn Java Unit Testing with JUnit 5 in 20 Steps - Step 15 - Tip - Unit Testing for Performance

The video tutorial explains how to conduct performance tests on specific methods using JUnit. It highlights the importance of performance testing, especially when methods need to run within certain time constraints. The tutorial covers the use of assertTimeout in JUnit 5, demonstrating how to set a duration for method execution and use lambda expressions to encapsulate the code. An example is provided where a method is tested to run within 5 seconds, but it fails, taking 12 seconds. The video concludes by emphasizing the value of integrating performance tests into unit testing to ensure critical methods remain efficient.

Why might you want to test the performance of a method?

• To confirm it is written in a functional style

• To check if it produces the correct output

• To ensure it runs within a specific time limit

• To verify it uses minimal memory

What is the main difference between JUnit 4 and JUnit 5 regarding performance testing?

• JUnit 5 only supports UI-based performance tests

• JUnit 5 requires a separate library for performance tests

• JUnit 5 does not support performance testing

• JUnit 5 uses assertTimeout instead of annotations

What is the purpose of using a lambda expression in assertTimeout?

• To define the code block to be tested

• To specify the timeout duration

• To handle exceptions during the test

• To log the test results

How can you specify the duration for assertTimeout?

• By using a command-line argument

• Through a configuration file

• By setting a global timeout in the test configuration

• Using Duration.of with various time units

In the provided example, what caused the test to fail?

• The loop ran longer than the specified timeout

• The code had a syntax error

• The method did not return the expected result

• The test was not executed properly

What was the actual execution time of the test in the example?

• 12.5 seconds

• 5 seconds

• 7.7 seconds

• 10 seconds

What is the benefit of including performance tests in unit tests?

• To eliminate the need for manual testing

• To simplify the code structure

• To reduce the number of test cases

• To ensure critical methods perform efficiently