refactor: tidy up app structure and entrypoint file

app.go

@@ -12,8 +12,14 @@ type Route struct {
 	Handler http.HandlerFunc
 }
 
-type API struct {
+type BackgroundTask struct {
+	Handler  func()
+	Interval time.Duration
+}
+
+type App struct {
 	Routes          []Route
+	BackgroundTasks []BackgroundTask
 	StaticRoot      string
 }
 
@@ -25,7 +31,7 @@ func LoggingMiddleware(f http.HandlerFunc) http.HandlerFunc {
 	}
 }
 
-func (a API) Start(addr string) {
+func (a App) Start(addr string) {
 	for _, route := range a.Routes {
 		http.HandleFunc(route.Path, LoggingMiddleware(route.Handler))
 	}
@@ -34,9 +40,28 @@ func (a API) Start(addr string) {
 		http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(a.StaticRoot))))
 	}
 
+	for _, task := range a.BackgroundTasks {
+		go func() {
+			for {
+				task.Handler()
+				time.Sleep(task.Interval)
+			}
+		}()
+	}
+
 	http.ListenAndServe(addr, nil)
 }
 
-func (a *API) AddRoute(path string, handler http.HandlerFunc) {
+func (a *App) AddRoute(path string, handler http.HandlerFunc) {
 	a.Routes = append(a.Routes, Route{Path: path, Handler: handler})
 }
+
+func NewApp(routes map[string]http.HandlerFunc, backgroundTasks []BackgroundTask, staticRoot string) *App {
+	app := App{StaticRoot: staticRoot, BackgroundTasks: backgroundTasks}
+
+	for route, handler := range routes {
+		app.AddRoute(route, handler)
+	}
+
+	return &app
+}

main.go

@@ -1,86 +1,12 @@
 package main
 
 import (
-	"encoding/json"
-	"fmt"
 	"net/http"
-	"net/url"
-	"text/template"
 	"time"
 )
 
 var SharedCache *Datastore
 
-type Link struct {
-	Url           string `json:"url"`
-	PublishedDate string `json:"publishedDate"`
-	Title         string `json:"title"`
-}
-
-// Healthcheck route
-//
-// Confirms that the app is alive without guarantees
-// about it being fully-functional.
-func healthcheck(w http.ResponseWriter, r *http.Request) {
-	w.WriteHeader(200)
-}
-
-// About page
-//
-// Static content for the about page.
-func about(w http.ResponseWriter, r *http.Request) {
-	tmpl, _ := template.New("about.html.tmpl").ParseFiles("templates/about.html.tmpl")
-	tmpl.Execute(w, nil)
-}
-
-// Feeds list
-//
-// Lists all feed elements in store.
-func listContent(w http.ResponseWriter, r *http.Request) {
-	links := []Link{}
-	for _, feed := range SharedCache.List("feeds") {
-		var formattedItems []Link
-		json.Unmarshal([]byte(feed), &formattedItems)
-		links = append(links, formattedItems...)
-	}
-
-	tmpl, _ := template.New("index.html.tmpl").ParseFiles("templates/index.html.tmpl")
-	tmpl.Execute(w, links)
-}
-
-// Manage content
-//
-// Interface to add new feed subscriptions and get a list
-// of current subs.
-func manageContent(w http.ResponseWriter, r *http.Request) {
-	if r.Method == "POST" {
-		r.ParseForm()
-
-		urlValue := r.PostFormValue("url")
-
-		if _, err := url.Parse(urlValue); err != nil {
-			w.WriteHeader(400)
-			return
-		}
-
-		cacheKey := fmt.Sprintf("feedurl:%s", urlValue)
-		SharedCache.Set(cacheKey, urlValue)
-
-		go fetchFeed(urlValue)
-
-		w.WriteHeader(201)
-	}
-
-	allFeeds := SharedCache.List("feedurl")
-
-	type ManageTmplData struct {
-		Feeds map[string]string
-	}
-
-	tmpl, _ := template.New("manage.html.tmpl").ParseFiles("templates/manage.html.tmpl")
-	tmpl.Execute(w, ManageTmplData{Feeds: allFeeds})
-}
-
 var routeMap = map[string]http.HandlerFunc{
 	"/":       listContent,
 	"/about":  about,
@@ -88,6 +14,10 @@ var routeMap = map[string]http.HandlerFunc{
 	"/ping":   healthcheck,
 }
 
+var bgTasks = []BackgroundTask{
+	{refreshFeeds, 10 * time.Minute},
+}
+
 func main() {
 	SharedCache = &Datastore{
 		Data: map[string]string{},
@@ -97,18 +27,5 @@ func main() {
 		SharedCache = existingStore
 	}
 
-	api := API{StaticRoot: "./static"}
-
-	for route, handler := range routeMap {
-		api.AddRoute(route, handler)
-	}
-
-	go func() {
-		for {
-			refreshFeeds()
-			time.Sleep(10 * time.Minute)
-		}
-	}()
-
-	api.Start(":9000")
+	NewApp(routeMap, bgTasks, "./static").Start(":9000")
 }

routes.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"text/template"
+)
+
+type Link struct {
+	Url           string `json:"url"`
+	PublishedDate string `json:"publishedDate"`
+	Title         string `json:"title"`
+}
+
+// Healthcheck route
+//
+// Confirms that the app is alive without guarantees
+// about it being fully-functional.
+func healthcheck(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(200)
+}
+
+// About page
+//
+// Static content for the about page.
+func about(w http.ResponseWriter, r *http.Request) {
+	tmpl, _ := template.New("about.html.tmpl").ParseFiles("templates/about.html.tmpl")
+	tmpl.Execute(w, nil)
+}
+
+// Feeds list
+//
+// Lists all feed elements in store.
+func listContent(w http.ResponseWriter, r *http.Request) {
+	links := []Link{}
+	for _, feed := range SharedCache.List("feeds") {
+		var formattedItems []Link
+		json.Unmarshal([]byte(feed), &formattedItems)
+		links = append(links, formattedItems...)
+	}
+
+	tmpl, _ := template.New("index.html.tmpl").ParseFiles("templates/index.html.tmpl")
+	tmpl.Execute(w, links)
+}
+
+// Manage content
+//
+// Interface to add new feed subscriptions and get a list
+// of current subs.
+func manageContent(w http.ResponseWriter, r *http.Request) {
+	if r.Method == "POST" {
+		r.ParseForm()
+
+		urlValue := r.PostFormValue("url")
+
+		if _, err := url.Parse(urlValue); err != nil {
+			w.WriteHeader(400)
+			return
+		}
+
+		cacheKey := fmt.Sprintf("feedurl:%s", urlValue)
+		SharedCache.Set(cacheKey, urlValue)
+
+		go fetchFeed(urlValue)
+
+		w.WriteHeader(201)
+	}
+
+	allFeeds := SharedCache.List("feedurl")
+
+	type ManageTmplData struct {
+		Feeds map[string]string
+	}
+
+	tmpl, _ := template.New("manage.html.tmpl").ParseFiles("templates/manage.html.tmpl")
+	tmpl.Execute(w, ManageTmplData{Feeds: allFeeds})
+}