A strange, and maybe funny, phenomenon that I notice after 10 years working in this industry is that developers can get really offended when someone calls out their solution as a hack. I’ve observed this in different companies, even some people who I consider calm and composed can get their attitude changed once I tell them that their solution is hacky. People tend to be very civil as long as I politely criticize their work in a friendly manner, but once the word “hack” is said, it’s as if I was personally attacking them....
Facade Design Pattern
In the previous post, we converted an incompatible interface ino another that fits nicely with our existing design thanks to the adapter pattern. We were able to design a weapon system that allows composing different damage types to different weapons, and also able to incorporate a third party library to add a specific type of weapon damage. While the exising solution works, it’s not very clean due to a few reasons....
Adapter Design Pattern
In our previous post, we leveraged the decorator design pattern to implement a weapon system for our next video game. Thanks to the decorator pattern, we were able to provide additional damage types to our weapons without changing the weapons’ implementation. Adding a new weapon therefore is very easy, and so is adding a new damage type. In this post, we’ll cover a different kind of problem that can be solved by the adapter design pattern....
Decorator Design Pattern
The decorator design pattern lets us provide additional behavior to a type. This design pattern is extremely powerful when we want to provide extra functionalities without requiring changes to an existing type, helping us achieve the Open Closed principle. In this post we’ll examine how the decorator design pattern handles a hypothetical problem. The code will be written in Golang, but the idea should be simple enough to port to other programming languages....
Contextual Error Handling in Go
Go provides 2 native ways to instatiate an error value: errors.New that returns a string error value, very useful to create a simple sentinel error value like var errNotFound = errors.New("record not found"). fmt.Errorf that may return an error that wraps another error, and the wrapped error can be asserted against with errors.Is, or retrieved with errors.As. While both approaches are fine for simple programs, they lack depth when it comes to large systems because of:...
Interface Pollution
In this article, we’ll look at a very common mistake that Golang new comers make, especially when they come from a background of Object Oriented Programming (OOP) languages like Java or C#. What is interface pollution? Let’s look at some codes. package employee type Employee struct { Name string Credit int } type EmployeeRepository interface { Query(name string) *Employee } func NewEmployeeRepository() EmployeeRepository { return &database{} } type database struct {} // Query returns the first Employee that has a matching name....
Value and Pointer Semantic
“How do you decide that a variable should be a pointer, or a value?” and “How do you know when to use pointer receiver and value receiver of a method?” are among the most common questions I receive from Go new comers. Even though there is no offical rule that dictates which types should use pointer, and which types should use value, it’s worth to deep dive into the topic of pointer and value semantic in Go, which is what we’ll do in this article....
About Single Responsibility Principle
Single Responsibility Principle (SRP) is the first one of the 5 famous principles that make up SOLID, a classic guideline to write clean and maintainable code, worshipped by a plethora of programmers worldwide. There exists various articles and workshops out there to explain the principle. Tech celebs support it, talk about it in social platforms. Many articles, however, does a poor job explaining the principle, resulting in a shallow and rigid understanding of the principle among developers....
Graceful Http Server Shutdown Experiment
In our previous article, we implemented a server in Golang that gracefully reacts to termination signals. We presented the problems of the hello world version of the server, how to address it, but did not perform any verification. In this article, we’ll prepare an experiment on both the graceful server, and also the not-so-graceful one to contrast their behavior. The experiment is done in a macOS environment, but the same process will work in Windows and Linux....
Git Bisect to the Rescue!
Last week I had an interesting experience at work. An application that my team has been working on showed a weird bug with the latest build. It was very difficult to locate the source of the bug, and there were a plethora of commits between the last working build and the latest one (it’s actually terrible to let this happen, but terrible things happen all the time anyway). Finding the offending commit in this case could shrink the area that we need to look at....