Hands-On Software Engineering with Golang

Open/closed principle

The open/closed principle was coined by Bertrand Meyer ^[24], who stated the following:

"A software module should be open for extension but closed for modification."

Almost all Go programs import and use types from a host of other packages, some being part of the Go standard library whereas other packages are provided by third parties. Any software engineer that imports a package into their code base should always safely assume that all the types that are exported by said package adhere to a contract that is guaranteed to be immutable. In other words, a package should not be able to modify the behavior of the types that are exported by other packages. While some programming languages allow this type of modification (via ...