I have written a fairly simple code. It simply “implements” the factory interface in a stateless way. It works as expected, however I got a warning from Golang linter that both make() and update() methods are unused, which is clearly not true.

Have I written non-idiomatic Golang code, or is linter just too stupid to understand it? In most other languages this wouldn’t be a problem, but Golang doesn’t allow you to ignore linter warnings.

package main

import "fmt"

type Foo struct {
    name string
}

type Factory[T any] interface {
    make() *T
    update(*T, string, string)
}

type FooFactory struct {
}

func (f *FooFactory) make() *Foo {
    return &Foo{}
}

func (f *FooFactory) update(foo *Foo, key string, val string) {
    switch key {
    case "name":
        foo.name = val
    }
}

type Service[T any] struct {
    factory Factory[T]
}

func (s *Service[T]) Run() {
    foo := s.factory.make()
    s.factory.update(foo, "name", "qwerty")
    fmt.Printf("%v", foo)
}

// prints qwerty
func main() {
    service := &Service[Foo]{
        factory: &FooFactory{},
    }
    service.Run()
}