Writing Better Code in Go with the Option Pattern

As developers, we are always looking for better ways to write code that is maintainable, testable, and scalable. In Go, we often see structs with many fields, which can make initialization a pain, especially when some fields are optional. It becomes even more challenging when there are many possible configuration combinations. One way to solve this problem is to use the option pattern, which is widely used in many Go libraries, such as <code>net/http</code>, <code>sqlx</code>, and <code>gorm</code>. <h1>Backstory</h1> The option pattern originated from functional programming, where functions accept optional arguments. Instead of using function overloading, which can make the codebase more complex, developers use functional options to provide a flexible interface that can be extended without breaking the existing API. In Go, the option pattern is widely used to simplify struct initialization. Instead of defining a large number of constructors with different parameters, we can define a single constructor that accepts a variadic number of functional options. <h1>Advantages</h1> Using the option pattern has many advantages: <h2>Flexibility</h2> Using functional options makes the API more flexible because we can extend it without breaking the existing API. We can add new options without modifying the existing code, and we can also provide default values for optional fields. <h2>Readability</h2> Using functional options improves code readability because it makes the initialization code more concise and easier to read. Instead of having many parameters, we have a clear list of options that the struct accepts. <a href="https://dsysd-dev.medium.com/writing-better-code-in-go-with-the-option-pattern-bb9283131407">Website</a>