TestLabs - Java Unit Testing Labs

This project contains hands-on labs for learning and practicing unit testing in Java using Mockito and TestNG. Each lab focuses on a specific concept, with simple, clear code examples and corresponding tests.

Table of Contents

• Lab 1: Mocking a Simple Service and Verifying Mock Interactions
• Lab 2: Writing a Simple TestNG Test and Using Data Providers
• Project Structure
• Setup and Running Tests

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Lab 1: Mocking a Simple Service and Verifying Mock Interactions

Location:

• Main code: testlabs/src/main/java/com/elitekaycy/testlabs/labs/simpleService/
• Test: testlabs/src/test/java/com/elitekaycy/testlabs/labs/MockTest.java

Overview

This lab demonstrates how to use Mockito to mock dependencies and verify interactions in a service class. The example is a simple user service that fetches user data from a repository.

Components

• User.java: A simple POJO representing a user with name and email.
• UserRepository.java: Simulates a data repository with a method to find a user by name.
• UserService.java: Service class that uses UserRepository to fetch user data.

Test

• MockTest.java:
  • Uses Mockito to mock UserRepository.
  • Injects the mock into UserService.
  • Tests that UserService.getUser(name) returns the expected user.
  • Verifies that the repository's findUserByName method was called.

Example Test Snippet

@Mock
private UserRepository userRepository;

@InjectMocks
private UserService userService;

@Test
public void testGetUser() {
    String name = "dickson";
    User user = new User(name, "dickson@gmail.com");

    when(userRepository.findUserByName(name)).thenReturn(user);

    User userResult = userService.getUser(name);

    assertNotNull(userResult);
    assertEquals(userResult.toString(), user.toString());

    verify(userRepository).findUserByName(name);
}

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Lab 2: Writing a Simple TestNG Test and Using Data Providers

Location:

• Main code: testlabs/src/main/java/com/elitekaycy/testlabs/labs/simpleSort/QuickSort.java
• Test: testlabs/src/test/java/com/elitekaycy/testlabs/labs/QuickSortTest.java

Overview

This lab demonstrates how to write unit tests for a sorting algorithm using TestNG, including the use of data providers for parameterized testing.

Components

• QuickSort.java:
  • Contains a static sort(int[] arr) method that sorts an array in ascending order using a simple (non-recursive) sorting algorithm.

Test

• QuickSortTest.java:
  • Tests the QuickSort.sort method with hardcoded arrays.
  • Uses a TestNG @DataProvider to supply multiple test cases.
  • Asserts that the output array is sorted as expected.

Example Test Snippet

@Test
public void unit_test_quicksort() {
    int[] arr = { 4, 3, 7, 1 };
    int[] result = QuickSort.sort(arr);
    int[] expected = { 1, 3, 4, 7 };
    for (int i = 0; i < result.length; i++) {
        assertEquals(expected[i], result[i]);
    }
}

@Test(dataProvider = "sortData")
public void test_quicksort_with_data_providers(int[] arr) {
    int[] result = QuickSort.sort(arr);
    assertTrue(result[0] <= result[1]);
    assertTrue(result[0] <= result[result.length - 1]);
}

@DataProvider(name = "sortData")
public Object[][] sortData() {
    return new Object[][] { { new int[] { 4, 3, 7, 1 } }, { new int[] { 17, 19, 12 } } };
}

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Project Structure

testlabs/
├── pom.xml
├── readme.md
├── src/
│   ├── main/
│   │   └── java/
│   │       └── com/elitekaycy/testlabs/
│   │           └── labs/
│   │               ├── simpleService/
│   │               │   ├── User.java
│   │               │   ├── UserRepository.java
│   │               │   └── UserService.java
│   │               └── simpleSort/
│   │                   └── QuickSort.java
│   └── test/
│       └── java/
│           └── com/elitekaycy/testlabs/
│               ├── labs/
│               │   ├── MockTest.java
│               │   └── QuickSortTest.java
│               └── DemoTest.java

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Setup and Running Tests

Prerequisites

• Java 21+
• Maven

Dependencies

The project uses the following dependencies (see testlabs/pom.xml):

• TestNG for unit testing
• Mockito for mocking

Running Tests

To run all tests, use:

cd testlabs
mvn test

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Additional Notes

• The DemoTest.java file is a simple demonstration and not part of the main labs.
• The labs are designed to be minimal and focused on demonstrating core testing concepts.

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Oauth Microservices Suite

This project includes a set of Spring Boot microservices demonstrating OAuth2 security, API Gateway, and service discovery using Eureka. Each service is independently runnable and configured for integration in a microservices architecture.

Structure

Oauth/
├── Albums-Resource-Server/
├── ApiGateway/
├── DiscoveryService/
├── Photos-Resource-Server/
├── Docker-Compose.yaml

Services

1. DiscoveryService

• Path: Oauth/DiscoveryService
• Purpose: Eureka server for service discovery.
• Key Tech: Spring Cloud Netflix Eureka.
• Entry Point: DiscoveryServiceApplication.java
• How to run:
  mvn spring-boot:run in the DiscoveryService directory.

2. ApiGateway

• Path: Oauth/ApiGateway
• Purpose: API Gateway for routing and securing requests.
• Key Tech: Spring Cloud Gateway, Eureka client.
• Entry Point: ApiGatewayApplication.java
• How to run:
  mvn spring-boot:run in the ApiGateway directory.

3. Albums-Resource-Server

• Path: Oauth/Albums-Resource-Server
• Purpose: OAuth2-protected resource server exposing album data.
• Key Tech: Spring Boot, OAuth2 Resource Server.
• Entry Point: AlbumsApplication.java
• How to run:
  mvn spring-boot:run in the Albums-Resource-Server directory.

4. Photos-Resource-Server

• Path: Oauth/Photos-Resource-Server
• Purpose: OAuth2-protected resource server exposing photo data.
• Key Tech: Spring Boot, OAuth2 Resource Server.
• Entry Point: PhotosApplication.java
• How to run:
  mvn spring-boot:run in the Photos-Resource-Server directory.

5. Docker Compose

• File: Oauth/Docker-Compose.yaml
• Purpose: Orchestrates all services for local development.

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Note:

• All services use Java 11 and Spring Boot 2.3.x.
• The resource servers require OAuth2 tokens for access.
• The API Gateway and resource servers register themselves with the Eureka Discovery Service.

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