vazlucas / courses-notes

A repository to store notes of some courses

Notes ✍

Here I will share and save some notes I'd take during some classes.

It can be from online or college courses

Learning to test Spring Boot

What is it for?

• Learn Important Concepts behind Test Driven Development
• Understand different types of testing - Unit, Integration, Functional
• Master the JUnit 5 Testing API
• Easily integrate Mockito with JUnit 5 Tests
• Migrate JUnit 4 tests to JUnit 5
• Test Spring Framework Applications with JUnit 5 and Mockito
• Write Unit Tests with Spring MVC Test
• Learn to use testing features of Spring Boot

Where is the course?

• Udemy

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Section 1 - Introduction

About

• Completed

• How to work with GitHub and compare my code with the instructor's code

• What IDE to use

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Section 2 - Introduction to testing software

About

• Completed

Why testing is great?

1. No more fix this and break that
2. Best practice in the industry
3. Proves that your code is running correctly

Types of tests

1. Unit test (the majority of tests)
    Should be fast, specific and light
2. Integration test
    Larger scope than unit test's, tests the overall behavior of the system
3. Funcional test
    Application is tipically live, tests specific functional points

TDD (test) x BDD (behavior)

1. TDD => write tests firt, code to fix tests, refactor code 
2. BDD => when something happens then this happens 
Use both!!!

Common testing frameworks for Java

1. JUnit
2. TestNG
3. Spock
4. Cucumber
5. Mockito
6. Spring MVC Test
7. REST Assured
8. Selenium

Continuous Integration

A development practice that requires developers to integrate code into a shared repository verified by an automated build detecting problems early for each contribution
1. Jenkins
2. Bamboo
3. TravisCI

Continuous Deployment

Should happen after every commit automatically deploying build artifacts after CI tests

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Section 3 - TDD by example

About

• Completed

Some quotes of Kent Beck, one of the Agile Manifesto signers and one of the JUnit developers, also author of Extreme Programming Explained and Test-Driven Development by Example

"I am not a great programmer, I am a good programmer with great habits"

"If there are forms of testing, like stress and load testing, that finds defect after development is completed, bring them into the development cycle. Run them continuously and automatically"

First approach to tests - TDD

1. Create the test class
2. Create a MVP for your code
3. Make a test run with the MVP
4. Gradually update the code to get the expected results
or
1. Write a test (how the code should work)
2. Write the code and make it run
3. Update the code

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Section 4 - Getting Started with JUnit

About

• Completed

JUnit Modules

JUnit Platform - The foundation for launching tests
JUnit Jupiter - Programmimg model for writing tests
JUnit Vintage - Test engine

JUnit dependecies in Maven

<properties>
  <junit-platform.version>5.3.1</junit-platform.version>
</properties>

<dependencies>
  <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <version>${junit-platform.version}</version>
      <scope>test</scope>
  </dependency>
  <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-engine</artifactId>
      <version>${junit-platform.version}</version>
      <scope>test</scope>
  </dependency>
</dependencies>

<build>
  <plugins>
      <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
      </plugin>
      <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.0</version>
          <configuration>
              <argLine>
                  --illegal-access=permit
              </argLine>
          </configuration>
      </plugin>
      <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-failsafe-plugin</artifactId>
          <version>2.22.0</version>
          <configuration>
              <argLine>
                  --illegal-access=permit
              </argLine>
          </configuration>
      </plugin>
  </plugins>
</build>

Annotations	What it is for
@Test	Determine a method as a test method
@BeforeEach	Run a method before each test
@AfterEach	Run a method after each test
@BeforeAll	Run a method before the tests
@AfterAll	Run a method after the tests
@RepeatedTes(times)	Run a test x times

Running test from command line with maven

1. Open the cmd
2. Move to your directory
3. Select the mvnw.cmd with two commands: clean and test

  mvnw.cmd clean test

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Section 5 - Testing Java with JUnit 5

About

• Completed

Example of assertion:

assertEquals(value: 2, value: 2, failure message: "Values do not match")

In JUnit documentation there are others

• You can use lambda expressions as an if statement when the assertion results in false
  • assertEquals (2, 2, () -> "Values do not match")
• You can use nested assertions with multiples assertAll

  assertAll ("message",
  
     ( ) -> assertAll ("message",
            ( ) -> assertEquals (value, value, "message"),
            ( ) -> assertEquals (value, value, "message"))
     ( ) -> assertAll ("message",
            ( ) -> assertEquals (value, value, "message"),
            ( ) -> assertEquals (value, value, "message"))
  
    ));
  

• You can also use some libraries of JUnit as AssertJ and Hamcrest to give some more options preset

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Section 6 - Advanced JUnit testing

About

• Completed
• You can add tags to your test and create a cofiguration to only run test with that especifically tag
• You can create test interfaces and implement them onto the classes you would want to test
• You can inject dependecies to be able to see extra info
  • TestInfo
  • RepetitionInfo
• @ExtendWith allows you to extend JUnit extensions

---

Section 7 - Test Execution

About

• Completed
• Test coverage is a handy tool to find out how much of your code is being covered in tests

---

Section 8 - JUnit 4 to JUnit 5 migration

About

• Completed
• Annotations differences from JUnit 4 to JUnit 5

JUnit 4	JUnit 5
@Before	@BeforeAll
@After	@AfterAll
@BeforeClass	@BeforeEach
@AfterClass	@AfterEach
@Catgory	@Tag

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Section 9 - Getting started with Mockito

About

• Completed
• Mockito is important to have light and fast tests not importing and using real files

Mockito dependencies in Maven (keep JUnit)

<dependencies>
  <dependency>
      <groupId>org.mockito</groupId>
      <artifactId>mockito-core</artifactId>
      <version>${mockito.version}</version>
      <scope>test</scope>
  </dependency>
  <dependency>
      <groupId>org.mockito</groupId>
      <artifactId>mockito-junit-jupiter</artifactId>
      <version>${mockito.version}</version>
      <scope>test</scope>
  </dependency>
</dependencies>

Creating Mockito Mocks with annotations

public class AnnotationMocksTest {
    @Mock
    Map<String, Object> mapMock;

    @BeforeEach
    void setUp() {
        MockitoAnnotations.initMocks(this);
    }
}

• @ExtendWith(MockitoExtension.class) is an annotation to extend a Mockito

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Section 10 - Behavior Driven Mockito

About

• Completed
• BDD is more of conceptual way of how you test your code
  • Given → when → then

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Section 11 - Advanced Mockito

About

• Completed

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Section 12 - Testing with Spring Framework

About

• Completed

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Section 13 - Spring Frameork Testing Context

About

• Completed

• @SpringJUnitConfig tells spring which configuration to use then you can set classes Config to be used as a context

• @Configuration tells spring that this class is a context configuration class

• @SpringJUnitConfig(classes = yourClass.TestConfig.class) tells spring to use an inner class configuration and it shoulg point to a @Configuration static class

• @ActiveProviles("yourProfile") and @Profile to set up specific profiles to your test and isolate classes and interfaces that are not need and could impact the test result

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Section 14 - Spring MVC Test

About:

• Completed

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Section 15 - Introduction to Testing with Spring Boot

About:

• Completed

• @SpringBootTest enables spring context

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Section 16 - Spring MVC Rest Controller

About:

• Completed

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Section 17 - Testing with Wiremock

About:

• Completed

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Section 18 - Spring MVC Rest Docs

About:

• Completed

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Section 19 - Appendix A

About:

• Completed

• A tool for generating API documentation

• Supports: JUnit 4 and 5 and Spock

• Tests will generate snippets that will be transformed to documentation by Asciidoctor

<dependencies>
    <dependency>
        <groupId>org.springframework.restdocs</groupId>
        <artifactId>spring-restdocs-mockmvc</artifactId>
        <scope>test</scope>
    </dependency>
   
</dependencies>

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