Start Docker from scratch

Docker is widely used but I haven't used it in my career. However, it is one of very useful softwares so it's time to le...

Difference between for, while, forEach, for-in and for-of

A lot of languages support several ways for loop logic. Typescript supports following ways for example.whileforfor in fo...

async/await with Promise in TypeScript

Using promise makes the code much faster. This post explains the basic and advanced usage.

How to write unit tests for a singleton class

Once a static field value changes in unit tests, the change applies to other tests because it's static. It's important to split it into two classes. One class has the main logic and the other stores the class to provide it as singleton.
Other techs

Start Powershell with specified execution policy without changing default

How to start powershellI often starts powershell.exe from an explorer instead of command prompt because it looks better ...

Using spread operator for process.env

I faced strange behavior when I used spread operator for process.env. In my project, our main source is Typescript but w...

How to write good unit tests?

Unit Test makes your software better in terms of not only quality but also class structure because you need to separate ...

Dev Environment in Docker Container

When we try something new we need to install something and then remove it if it is no longer necessary but our PC will g...

Dependency injection in Typescript. Constructor? Setter? Factory method?

Decoupling class relationships is important for unit testing. Less cohesion makes writing unit tests easier. This post shows 3 ways to do it. Constructor injection, setter injection, and using the factory method to inject the desired instance.