Refactor and optimize code: streamline error

handling, remove redundant return statements,
correct gorm tag syntax, and improve type
assertions in relay.go

common/custom-event.go

@@ -39,10 +39,6 @@ func checkWriter(writer io.Writer) stringWriter {
 var contentType = []string{"text/event-stream"}
 var noCache = []string{"no-cache"}
 
-var fieldReplacer = strings.NewReplacer(
-	"\n", "\\n",
-	"\r", "\\r")
-
 var dataReplacer = strings.NewReplacer(
 	"\n", "\ndata:",
 	"\r", "\\r")
@@ -60,9 +56,15 @@ func encode(writer io.Writer, event CustomEvent) error {
 }
 
 func writeData(w stringWriter, data interface{}) error {
-	dataReplacer.WriteString(w, fmt.Sprint(data))
+	_, err := dataReplacer.WriteString(w, fmt.Sprint(data))
+	if err != nil {
+		return err
+	}
 	if strings.HasPrefix(data.(string), "data") {
-		w.writeString("\n\n")
+		_, err := w.writeString("\n\n")
+		if err != nil {
+			return err
+		}
 	}
 	return nil
 }

common/embed-file-system.go

@@ -2,9 +2,10 @@ package common
 
 import (
 	"embed"
-	"github.com/gin-contrib/static"
 	"io/fs"
 	"net/http"
+
+	"github.com/gin-contrib/static"
 )
 
 // Credit: https://github.com/gin-contrib/static/issues/19
@@ -15,10 +16,7 @@ type embedFileSystem struct {
 
 func (e embedFileSystem) Exists(prefix string, path string) bool {
 	_, err := e.Open(path)
-	if err != nil {
-		return false
-	}
-	return true
+	return err == nil
 }
 
 func EmbedFolder(fsEmbed embed.FS, targetPath string) static.ServeFileSystem {

common/utils.go

@@ -2,7 +2,6 @@ package common
 
 import (
 	"fmt"
-	"github.com/google/uuid"
 	"html/template"
 	"log"
 	"math/rand"
@@ -13,6 +12,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/google/uuid"
 )
 
 func OpenBrowser(url string) {
@@ -106,13 +107,13 @@ func Seconds2Time(num int) (time string) {
 }
 
 func Interface2String(inter interface{}) string {
-	switch inter.(type) {
+	switch v := inter.(type) {
 	case string:
-		return inter.(string)
+		return v
 	case int:
-		return fmt.Sprintf("%d", inter.(int))
+		return fmt.Sprintf("%d", v)
 	case float64:
-		return fmt.Sprintf("%f", inter.(float64))
+		return fmt.Sprintf("%f", v)
 	}
 	return "Not Implemented"
 }
@@ -138,14 +139,17 @@ func GetUUID() string {
 const keyChars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 
 func init() {
-	rand.Seed(time.Now().UnixNano())
+	s := rand.NewSource(time.Now().UnixNano())
+	rand.New(s)
 }
 
 func GenerateKey() string {
-	rand.Seed(time.Now().UnixNano())
+	var src = rand.NewSource(time.Now().UnixNano())
+	var r = rand.New(src)
+
 	key := make([]byte, 48)
 	for i := 0; i < 16; i++ {
-		key[i] = keyChars[rand.Intn(len(keyChars))]
+		key[i] = keyChars[r.Intn(len(keyChars))]
 	}
 	uuid_ := GetUUID()
 	for i := 0; i < 32; i++ {
@@ -159,10 +163,12 @@ func GenerateKey() string {
 }
 
 func GetRandomString(length int) string {
-	rand.Seed(time.Now().UnixNano())
+	var src = rand.NewSource(time.Now().UnixNano())
+	var r = rand.New(src)
+
 	key := make([]byte, length)
 	for i := 0; i < length; i++ {
-		key[i] = keyChars[rand.Intn(len(keyChars))]
+		key[i] = keyChars[r.Intn(len(keyChars))]
 	}
 	return string(key)
 }