learn_golang/learn_go_with_tests/dependency_injection/greet.go

package main

import (
	"fmt"
	"io"
	"log"
	"net/http"
)

func Greet(writer io.Writer, name string) {
	fmt.Fprintf(writer, "Hello, %s\n", name)
}

// func main() {
// 	Greet(os.Stdout, "Drew")
// }

// Here you can see that since now our greeter function takes an object that
// implements the io.Writer interface we can now pass an object like the http.ResponseWriter
// to it. DI let's us reuse our code in a new context.
func MyGreeterHandler(w http.ResponseWriter, r *http.Request) {
	Greet(w, "world")
}

func main() {
	log.Fatal(http.ListenAndServe(":5001", http.HandlerFunc(MyGreeterHandler)))
}