Hello! First of all, thanks for this project. It is very helpful and makes dependency injection a breeze.
We've experience some problems working with wire and generics (as I think other people has experienced too according to #354)
I dont know for sure if these changes added full support for generics but I've managed to fix all the issues I had in my projects.
Mainly, I had to update the dependencies to use golang.org/x/[email protected]
The main issue was here:
https://github.com/golang/tools/blob/master/go/ast/astutil/rewrite.go#L255
that was included in this commit
this is a version adapted from the tutorial that works only with the updated version:
// main.go
package main
import (
"errors"
"fmt"
"os"
"time"
)
// Message is what greeters will use to greet guests.
type Message string
type Resolver[K comparable, V any] struct {
store map[K]V
}
func NewResolver[K comparable, V any]() Resolver[K, V] {
return Resolver[K, V]{
store: map[K]V{},
}
}
func (o Resolver[K, V]) Resolve(key K) (V, error) {
val, exists := o.store[key]
if !exists {
return val, errors.New("not found")
}
return val, nil
}
func (o Resolver[K, V]) Add(key K, val V) {
o.store[key] = val
}
// NewMessage creates a default Message.
func NewMessage(phrase string) Message {
return Message(phrase)
}
// NewGreeter initializes a Greeter. If the current epoch time is an even
// number, NewGreeter will create a grumpy Greeter.
func NewGreeter(m Resolver[bool, Message]) Greeter {
var grumpy bool
if time.Now().Unix()%2 == 0 {
grumpy = true
}
return Greeter{MessageResolver: m, Grumpy: grumpy}
}
// Greeter is the type charged with greeting guests.
type Greeter struct {
Grumpy bool
MessageResolver Resolver[bool, Message]
}
// Greet produces a greeting for guests.
func (g Greeter) Greet() Message {
m, err := g.MessageResolver.Resolve(g.Grumpy)
if err != nil {
return Message("not found")
}
return m
}
// NewEvent creates an event with the specified greeter.
func NewEvent(g Greeter) (Event, error) {
if g.Grumpy {
return Event{}, errors.New("could not create event: event greeter is grumpy")
}
return Event{Greeter: g}, nil
}
// Event is a gathering with greeters.
type Event struct {
Greeter Greeter
}
// Start ensures the event starts with greeting all guests.
func (e Event) Start() {
msg := e.Greeter.Greet()
fmt.Println(msg)
}
func main() {
e, err := InitializeEvent("hi there!")
if err != nil {
fmt.Printf("failed to create event: %s\n", err)
os.Exit(2)
}
e.Start()
}
// wire.go
package main
import "github.com/google/wire"
func getMessageResolver() Resolver[bool, Message] {
r := NewResolver[bool, Message]()
r.Add(false, Message("happy false"))
r.Add(true, Message("grumpy true"))
return r
}
// InitializeEvent creates an Event. It will error if the Event is staffed with
// a grumpy greeter.
func InitializeEvent(phrase string) (Event, error) {
wire.Build(NewEvent, NewGreeter, getMessageResolver)
return Event{}, nil
}
![wire: don't work with go modules [go v.1.11.1]](https://avatars.githubusercontent.com/u/21968823?v=4)
