Use waiter interface instead of time.Sleep

cmd/app/app.go

@@ -4,13 +4,21 @@ import (
 	"github.com/initialcapacity/go-streaming/internal/app"
 	"github.com/initialcapacity/go-streaming/pkg/websupport"
 	"log"
+	"time"
 )
 
+type oneSecondWaiter struct {
+}
+
+func (w oneSecondWaiter) Wait() <-chan time.Time {
+	return time.After(1 * time.Second)
+}
+
 func main() {
 	host := websupport.EnvironmentVariable("HOST", "")
 	port := websupport.EnvironmentVariable("PORT", 8777)
 
-	server := websupport.NewServer(app.Handlers(true))
+	server := websupport.NewServer(app.Handlers(oneSecondWaiter{}))
 
 	_, done := server.Start(host, port)
 	log.Fatal(<-done)

internal/app/handlers.go

@@ -5,9 +5,9 @@ import (
 	"net/http"
 )
 
-func Handlers(addArtificialDelay bool) func(mux *http.ServeMux) {
+func Handlers(delay waiter) func(mux *http.ServeMux) {
 	return func(mux *http.ServeMux) {
-		mux.HandleFunc("GET /", Index(addArtificialDelay))
+		mux.HandleFunc("GET /", Index(delay))
 		mux.HandleFunc("GET /health", Health)
 
 		static, _ := fs.Sub(Resources, "resources/static")

internal/app/health_test.go

@@ -5,10 +5,22 @@ import (
 	"github.com/initialcapacity/go-streaming/pkg/testsupport"
 	"github.com/initialcapacity/go-streaming/pkg/websupport"
 	"testing"
+	"time"
 )
 
+type immediateWaiter struct {
+}
+
+func (w immediateWaiter) Wait() <-chan time.Time {
+	c := make(chan time.Time)
+	go func() {
+		c <- time.Now()
+	}()
+	return c
+}
+
 func TestHealth(t *testing.T) {
-	server := websupport.NewServer(app.Handlers(false))
+	server := websupport.NewServer(app.Handlers(immediateWaiter{}))
 	port, _ := server.Start("localhost", 0)
 	testsupport.AssertHealthy(t, port, "/health")
 }

internal/app/index.go

@@ -11,14 +11,16 @@ type model struct {
 	Message deferrable.Deferrable[[]string]
 }
 
-func Index(addArtificialDelay bool) http.HandlerFunc {
+type waiter interface {
+	Wait() <-chan time.Time
+}
+
+func Index(delay waiter) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		data := make(chan []string)
 
 		go func() {
-			if addArtificialDelay {
-				time.Sleep(1 * time.Second)
-			}
+			<-delay.Wait()
 			data <- []string{"Here's some slow content.", "It took a while to load.", "And didn't use any javascript."}
 			close(data)
 		}()

internal/app/index_test.go

@@ -10,7 +10,7 @@ import (
 )
 
 func TestIndex(t *testing.T) {
-	address, server := testsupport.StartTestServer(t, app.Handlers(false))
+	address, server := testsupport.StartTestServer(t, app.Handlers(immediateWaiter{}))
 	defer testsupport.StopTestServer(t, server)
 
 	response, err := http.Get(address)