So here's a playground example of using functional options and error handling: https://play.golang.org/p/cfw7axv6pjO
The advantage over method chaining is that we can return our errors correctly this way. Using the following as an example, I can return my error the whole way to the function call in main() and only need to handle it in a single place.
type MethodOption func(*http.Request) (*http.Request, error)
func NewRequest(opt ...MethodOption) (*http.Request, error) {
r := &http.Request{}
var err error
for _, opt := range opt {
r, err = opt(r)
if err != nil {
return nil, err
}
}
return r, nil
}
func SetURL(URL string) MethodOption {
return func(r *http.Request) (*http.Request, error) {
u, err := url.Parse(URL)
if err != nil {
return nil, err
}
r.URL = u
return r, nil
}
}
req, err := NewRequest(
SetURL("https://google.com"),
)
if err!= nil {
fmt.Println(err)
os.Exit(1)
}
