Go Component Design

Internal

• Go Engineering

Organizatorium

Prefer this style:

func main() {
  cfg := GetConfig()
  db, err := ConnectDatabase(cfg.URN)
  if err != nil {
    panic(err)
  }
  repo := NewPersonRepository(db)
  service := NewPersonService(cfg.AccessToken, repo)
  server := NewServer(cfg.ListenAddr, service)
  server.Run()
}

We get explicitness: each component is constructed in dependency order, with errors handled in-line as they occur. Each constructor enumerates its dependencies as parameters, allowing new code readers to easily build the mental model of the relationship between the components, and nothing is obscured behind layers of indirection. If a refactoring requires a component to acquire a new dependency, it simply needs to be added to the relevant constructor. The next compile will trigger errors along the dependency lists, the and the diff result in the PR will clearly show the flow of dependencies throughout the program. This brings the failure detection in miswired components at compile-time, rather than deferring to runtime.

More details here: Peter Bourgon - Best Practices for Industrial Programming