Repositories are a special example of a class. They usually have a lot of methods designed to retrieve data from the database or the other storage. To mark this operation in the name of the method, we can use one of the common words: find, get, search. Are all them mean the same? In this article, I would like to show you a practical difference between getById and findById methods.

JavaScript is one of the most versatile programming languages I know, however, I had a constant problem with the testing. Since I run into TDD, I was looking for something that allows me to build my solutions using this approach. When I had been creating a small project in React, I accidentally discovered Jest.

It surprised me because it hadn’t required any extra configuration. I thought that the configuration was built-in into the create-react-app tool. It turns out that zero-configuration is one of the philosophies behind this tool. I decided to try using it outside the React application. Since this moment, this is a standard tool for my unit tests for the JavaScript.

Let me show how easy work with Jest is.

I joined to the project that was developed by one guy. He was an amazing developer with plenty of ideas and skills. He had also the best knowledge about the system – its domain, architecture, used solutions, hidden tricks, and workarounds. In every single task, I needed his support because I didn’t understand how things worked. My main goal was to retrieve as much knowledge as possible from his head. The reason was simple – his contract is ending in a month. I wish I didn’t know about it before.

The project had the long to-do list of features. Some of them were partially implemented. Some other functionalities had specified time–frame because of the seasonal nature of the project. Everything was important from the business point of view.

There were no tests, no code’s style guide, no documentation (besides a few out of date README.md files across repository). I didn’t want to touch anything because the code was unstable and cause a lot of side–effects. After one month of torment, I thought – “f*ck it, let’s make it works”.

I didn’t always work in a larger team. At the beginning of my journey as a computer programmer, I was the only one person in a project. It meant that I had had a free-hand (or semi-free-hand) to choose how I could write a code and which solutions I could use. From day to day I could perform a little revolution in the codebase. No consequences and no problems because the only user of the code was me.

Although this situation might look as the best case for a programmer, it doesn’t. Especially for the junior programmer. You have no opportunity to learn from someone else. You can’t validate your ideas and thoughts with others. Ultimately your only friends and co-workers are Google and Mr. StackOverflow.

After some time, I got a new job and I started to work as a part of the team. As a new person in the company, I had tons of ideas and tools that we could use in a project to make our work better, more pleasant and easier. It was relatively easy to introduce new features into the codebase. On the other hand, it was almost impossible to remove the old ones. Why?

Because we didn’t have the code deprecation strategy.

It may sound obvious or even weird for people who programming in statically typed or compiled languages. In my work, I use PHP which is a dynamically typed language with optional strict typing introduced in version 7. At the beginning of my journey with PHP, I didn’t care so much about typing. I had a trivial cause — they didn’t exist yet.

I used to write a code without thinking about types. It was convenient and fast. Furthermore, it allowed writing proxy functions which recognize parameters type and it runs the proper function. Yes, overriding doesn’t exist in PHP.

But things changed when I discovered polymorphism. The magic keyword Interface that allows us to define the mandatory set of features in the object. The picture of writing a code without worrying about missing methods was incredible. I still didn’t understand one thing yet. How interfaces help me since I can pass everything on the function call?

This question lied a long time in my head until I discovered I can define the required type of passed object. Since that time, I changed completely the way how I write the code.

When we talk about arrays we usually mean the vector of something – primitives, objects or even arrays. But there are a lot of situation when we need to carry extra information with our data. We can use nested arrays but it doesn’t cause that the specific item within the array will be easy to identify. To achieve it we should use custom keys. They provide easy access to any element of the array as long as we know the key corresponding with that value.

There are some reasons why we can use associative arrays instead of simple vectors, e.g. readability. Named keys are also more meaningful than numeric indexes. Instead of thinking about the whys, image the situation when we could use a hashmap. Let’s focus on how we can build the associative array from a vector.

If you frown after reading idempotence, don’t worry. Although this word sounds unusual it conceals a simple mathematics property. Needless to say, this characteristic has also a big meaning in Computer Science.

Idempotence operation is an operation that can be applied multiple times without changing the result beyond the initial application. It may sound difficult but after a couple of examples, the general concept will be obvious.

When I started my journey as a computer programmer, I had written my code in various way. In most cases, I translated requirements into specific conditions and statements, but I hadn’t taken too much care of readability or quality of my code. “It works, that’s it” – and the code base grew and grew in time. Thousands of written methods later, I had discovered that a lot of these little pieces of logic could look better if I reverse some condition within them. Unconsciously, I’ve started following the rule which I had later called the “fail fast” rule, and subsequently “return early”.

I realized I hadn’t had the one preferred way to check conditions within the single method. Sometimes I let execution if the expression was true. Another time I had waited for the false result to show the error message before the main part of the code was executing. In my head, I discovered various styles of checking conditions.

I remember how I was excited discovering how much frontend frameworks like AngularJS could make my work easier. Even though I was a strong backend-oriented programmer I decided to learn the concept of Angular. I dug into it at ease and I started using this tool in my daily work.

Since I changed my job I lost the opportunity to use frontend technologies regularly. However, I’m still fascinated about this part of software development and I follow trends and latest changes. Therefore AngularJS 1.x was officially abandoned I started looking for something new and fresh.

I didn’t look for a long time. When I first saw React library, I fall in love with it. I quickly caught the concept behind this tool, thanks to ubiquitous tutorials and examples. I read a lot about the flux pattern, redux, components but I didn’t chance to use them in something more ambitious than <HelloWorld/> component. Till now.

Loop is the basic construction in each programming language. All repeatable operations are being done using loops. I think you know how the basic loops like while, do and for work and when you should use one of them. But are you sure? Maybe should you use array functions?

How many of your operations in a loop rely on building objects based on the value? Or selecting only a few items from the array using a predicate? Maybe you use array values to calculate something? Whatever you do, read why you should replacing basic loops by array operations.