Monthly Archives: February 2025

Microservice Architecture

In today’s fast-paced digital natural world, software systems are required to be scalable, adaptable, and powerful. Microservice architecture is one architectural approach that has gained significant popularity in answering these objectives. Recently, I discovered a helpful document named “Microservices Architecture” on Microsoft’s Azure Architecture Center website, which offered a full description of this technique.

The article describes microservices architecture as a design pattern in which applications are developed as a collection of small, independent, and loosely linked services. Each service is liable for an independent function and may be built, launched, and expanded separately. This differs from monolithic systems, which have all components tightly integrated into a single codebase. The article highlights the advantages of microservices, such as increased scalability, shorter development cycles, and the option to utilize various technologies for different services. It also addresses difficulties like increased complexity in managing inter-service communication, data consistency, and deployment pipelines.

The reason I chose this article is because Microsoft Azure is a cloud computing platform that I am familiar with and am learning more about how it is within microservice architecture. The article’s clear explanations and practical insights make it an excellent pick for learning about microservices in a real-world setting.

Reading the article was an eye-opening experience. I was particularly struck by the emphasis on independence and modularity in microservices. The thought of each service being created and deployed individually appealed to me since it enables teams to work on different areas of an application without stepping on each other’s toes. This method not only accelerates development but also makes it easier to discover and resolve problems.

However, this article also made me aware of the issues that come with microservices. For example, maintaining communication across services necessitates careful design, while guaranteeing data consistency between services can be challenging. This helped me realize the value of solutions like API gateways and message brokers, which assist to speed these operations.

One of the most important lessons that I learned is that microservices aren’t a one-size-fits-all solution. The article highlights that this architecture is best suited for big, complicated applications that demand a high level of scalability and flexibility. For smaller projects, a monolithic approach may be more suitable. This sophisticated viewpoint helped me comprehend that the correct architecture is determined by the project’s individual requirements.

In the future, I plan to apply microservices architectural ideas to my own projects. I’m particularly looking forward to exploring containerization technologies like Docker and orchestration platforms like Kubernetes, both of which are commonly used in microservices setups. I’ll also remember how important it is to build clear APIs and implement effective monitoring mechanisms to handle the complexity of distributed systems.

https://learn.microsoft.com/en-us/azure/architecture/guide/architecture-styles/microservices

From the blog CS@Worcester – computingDiaries by hndaie and used with permission of the author. All other rights reserved by the author.

Effective Exception Testing in JUnit 5: Boundary Value Testing and AssertThrows

Introduction

In modern software development, ensuring that a program handles exceptions correctly is crucial for building robust applications. Exception testing in JUnit 5 allows developers to verify that their code properly handles error scenarios, improving reliability and maintainability. This blog post explores key techniques such as Testing for Exceptions in JUnit 5, Boundary Value Testing, and using AssertThrows to create effective test cases.

Testing for Exceptions in JUnit 5

JUnit 5 provides a streamlined way to test exceptions in Java applications. Unlike JUnit 4, which required using the expected attribute or @Rule, JUnit 5 introduces Assertions.assertThrows(), offering a more flexible and readable approach.

Example of Exception Testing in JUnit 5

Consider a method that calculates the square root of a number. If a negative number is provided, it should throw an IllegalArgumentException.

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;

class MathUtilsTest {

    double calculateSquareRoot(double number) {
        if (number < 0) {
            throw new IllegalArgumentException("Number must be non-negative");
        }
        return Math.sqrt(number);
    }

    @Test
    void testCalculateSquareRootException() {
        IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {
            calculateSquareRoot(-5);
        });
        assertEquals("Number must be non-negative", exception.getMessage());
    }
}

This test verifies that the method correctly throws an exception when given invalid input, ensuring robustness.

Boundary Value Testing

Boundary Value Testing (BVT) is a technique used to test the limits of input values. It focuses on edge cases, such as minimum and maximum values, where software is most likely to fail.

Example: Boundary Testing for Age Validation

Consider a function that validates a user’s age for registration, allowing only ages between 18 and 65.

boolean isValidAge(int age) {
    return age >= 18 && age <= 65;
}

Boundary tests should check values just inside and just outside the valid range:

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;

class AgeValidatorTest {
    
    @Test
    void testAgeBoundaries() {
        assertTrue(isValidAge(18)); 
        assertTrue(isValidAge(65));  
        assertFalse(isValidAge(17)); 
        assertFalse(isValidAge(66)); 
    }
}

BVT ensures the system correctly distinguishes between valid and invalid inputs.

Testing for Exceptions with AssertThrows

The assertThrows method in JUnit 5 simplifies exception testing, making tests more readable and maintainable. It helps validate that methods correctly handle invalid inputs by throwing the expected exceptions.

Example: Division by Zero Handling

Consider a simple method that performs division:

int divide(int dividend, int divisor) {
    if (divisor == 0) {
        throw new ArithmeticException("Cannot divide by zero");
    }
    return dividend / divisor;
}

We can use assertThrows to verify proper exception handling:

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;

class DivisionTest {

    @Test
    void testDivideByZero() {
        ArithmeticException exception = assertThrows(ArithmeticException.class, () -> {
            divide(10, 0);
        });
        assertEquals("Cannot divide by zero", exception.getMessage());
    }
}

This ensures that the division method correctly throws an exception when dividing by zero.

Conclusion

Testing exceptions effectively is a vital part of software quality assurance. JUnit 5’s assertThrows method, combined with Boundary Value Testing, enables developers to create thorough test cases that improve the reliability and robustness of applications. By writing well-structured exception tests, developers can prevent unexpected failures and ensure their applications behave as expected under various conditions.

For further reading, check out:

#JUnit5 #ExceptionTesting #AssertThrows #BoundaryValueTesting

From the blog Rick’s Software Journal by RickDjouwe1 and used with permission of the author. All other rights reserved by the author.

On Being a Software Apprentice

In this post, I’ll be discussing my thoughts primarily on Chapter 1 of Apprenticeship Patterns. I really like the idea of being a “Software Apprentice,” as I think it is a good representation of the attitude I have adopted over the years. I’ve always viewed myself as someone who is constantly learning and evolving in this field, and the apprenticeship model seems to align perfectly with that. It’s not about arriving at some endpoint but about growing, making mistakes, and improving.

What stood out to me the most was the idea of viewing the development process as a journey, not a destination. Chapter 1 introduces the concept of “Software Craftsmanship” as more than just technical skill, but also as a mindset of continuous learning. This was particularly thought-provoking because I think there’s a tendency, especially early in our careers, to think of coding as a task to be completed or a skill to be mastered and then moved beyond while in pursuit of some computer science career. However, the idea that becoming a Software Craftsman is an ongoing process—a commitment to constant improvement and a mindset that thrives on learning—is something that I think is a better description. It shifted my perspective on what it means to be good at coding- it’s not enough to know how to do something today, it’s about always finding a way to improve your code in the future.

In the past, specifically in my career, I’ve often gotten caught up in the day-to-day rush of just getting whatever piece of code done. I’ve rushed to get things coded, with the focus being on completing projects rather than developing deeper expertise or refining my approach to coding. After reading this chapter, I think I’m more likely to focus on the long-term value of writing quality code and the importance of standards. It’s not just about writing code that works; it’s about writing code that lasts, is readable, and contributes to a more sustainable project. I’m going to start to approach my coding tasks with a deeper goal, rather than rushing through them for the sake of completion.

As for the chapters that seem most relevant to me, I’d say Chapter 2 and Chapter 3 are particularly interesting. Chapter 2 addresses the Apprentice phase, which is where I find myself right now. It talks about how to build your foundational skills, seek out learning opportunities, and adopt the mindset of a lifelong learner – things I’m actively working on. Chapter 3, which discusses the Journeyman phase, is also relevant to me because it’s about expanding your skill set and finding ways to deepen your experience. I’m interested in how this phase encourages finding ways to take on more responsibility and become a more well-rounded developer, which is exactly where I want to focus next in my development journey.