Serve properly a single page app

main.go

@@ -4,12 +4,38 @@ import (
 	"flag"
 	"log"
 	"net/http"
+	"os"
+	"path/filepath"
 
 	"0xacab.org/meskio/cicer/api"
 	"github.com/gorilla/mux"
 	"github.com/olivere/env"
 )
 
+type handler struct {
+	assets string
+}
+
+func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	path, err := filepath.Abs(r.URL.Path)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	path = filepath.Join(h.assets, path)
+	_, err = os.Stat(path)
+	if os.IsNotExist(err) {
+		http.ServeFile(w, r, h.assets)
+		return
+	} else if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	http.FileServer(http.Dir(h.assets)).ServeHTTP(w, r)
+}
+
 func main() {
 	var (
 		dbPath  = flag.String("db-path", env.String("./test.db", "DB_PATH"), "Path where the sqlite will be located {DB_PATH}")
@@ -28,6 +54,7 @@ func main() {
 	}
 
 	log.Println("assets:", *assets)
-	r.PathPrefix("/").Handler(http.FileServer(http.Dir(*assets)))
+	h := handler{*assets}
+	r.PathPrefix("/").Handler(h)
 	log.Fatal(http.ListenAndServe(*addr, r))
 }