update the deprecated usages

Author: xgfone

config_test.go

@@ -180,7 +180,7 @@ func TestConfig(t *testing.T) {
 	}
 
 	names := make([]string, len(opts))
-	for i := 0; i < len(opts); i++ {
+	for i := range len(opts) {
 		names[i] = opts[i].Name
 	}
 	UnregisterOpts(names...)

decoder.go

@@ -130,14 +130,13 @@ func NewIniDecoder(defaultGroupName ...string) Decoder {
 				continue
 			}
 
-			n := strings.IndexByte(line, '=')
-			if n < 0 {
+			key, value, found := strings.Cut(line, "=")
+			if !found {
 				return fmt.Errorf("the %dth line misses the separator '='", index)
 			}
 
-			// Get the key
-			key := strings.TrimSpace(line[:n])
-			if len(key) == 0 {
+			// Check the key
+			if key = strings.TrimSpace(key); len(key) == 0 {
 				return fmt.Errorf("empty identifier key")
 			}
 			for _, r := range key {
@@ -146,9 +145,8 @@ func NewIniDecoder(defaultGroupName ...string) Decoder {
 				}
 			}
 
-			// Get the value
-			value := strings.TrimSpace(line[n+1:])
-			if value == "" { // Ignore the empty value
+			// Check the value
+			if value = strings.TrimSpace(value); value == "" { // Ignore the empty value
 				continue
 			} else if _len := len(value) - 1; value[_len] == '\\' { // The continuation line
 				vs := []string{strings.TrimSpace(strings.TrimRight(value, "\\"))}

source_env.go

@@ -47,25 +47,27 @@ func (e envSource) Watch(<-chan struct{}, func(DataSet, error) bool) {}
 func (e envSource) Read() (DataSet, error) {
 	vs := make(map[string]string, 32)
 	for _, env := range os.Environ() {
-		index := strings.IndexByte(env, '=')
-		if index == -1 {
+		key, value, found := strings.Cut(env, "=")
+		if !found {
 			continue
 		}
 
-		value := strings.TrimSpace(env[index+1:])
-		if value == "" {
+		if value = strings.TrimSpace(value); value == "" {
+			continue
+		}
+
+		if key = strings.ToLower(strings.TrimSpace(key)); key == "" {
 			continue
 		}
 
-		key := strings.ToLower(strings.TrimSpace(env[:index]))
 		if e.prefix != "" {
 			if !strings.HasPrefix(key, e.prefix) {
 				continue
 			}
 			key = strings.TrimPrefix(key, e.prefix)
 		}
 
-		key = strings.Replace(strings.Trim(key, "_"), "_", ".", -1)
+		key = strings.ReplaceAll(strings.Trim(key, "_"), "_", ".")
 		if key != "" {
 			vs[key] = value
 		}

source_flag.go

@@ -40,7 +40,7 @@ func PrintFlagUsage(flagSet *flag.FlagSet) {
 			s += " " + name
 		} else {
 			vf := reflect.ValueOf(f.Value)
-			if vf.Kind() == reflect.Ptr {
+			if vf.Kind() == reflect.Pointer {
 				vf = vf.Elem()
 			}
 			if vf.Kind() == reflect.Bool {
@@ -56,7 +56,7 @@ func PrintFlagUsage(flagSet *flag.FlagSet) {
 			// for both 4- and 8-space tab stops.
 			s += "\n    \t"
 		}
-		s += strings.Replace(usage, "\n", "\n    \t", -1)
+		s += strings.ReplaceAll(usage, "\n", "\n    \t")
 		s += fmt.Sprintf(" (default: %q)", f.DefValue)
 		fmt.Fprint(os.Stderr, s, "\n")
 	})
@@ -102,7 +102,7 @@ func addAndParseOptFlag(parse bool, c *Config, flagSet ...*flag.FlagSet) error {
 			continue
 		}
 
-		name := strings.Replace(opt.Name, "_", "-", -1)
+		name := strings.ReplaceAll(opt.Name, "_", "-")
 		switch v := opt.Default.(type) {
 		case nil:
 			flagset.String(name, "", opt.Help)
@@ -208,7 +208,7 @@ func (f flagSource) Read() (DataSet, error) {
 		default:
 			value = v.String()
 		}
-		vs[strings.Replace(f.Name, "-", "_", -1)] = value
+		vs[strings.ReplaceAll(f.Name, "-", "_")] = value
 	})
 
 	data, err := json.Marshal(vs)

validator.go

@@ -20,6 +20,7 @@ import (
 	"net/mail"
 	"net/url"
 	"regexp"
+	"slices"
 	"strconv"
 )
 
@@ -127,10 +128,8 @@ func NewStrArrayValidator(array []string) Validator {
 			return errNotString
 		}
 
-		for _, v := range array {
-			if s == v {
-				return nil
-			}
+		if slices.Contains(array, s) {
+			return nil
 		}
 		return fmt.Errorf("the value '%s' is not in %v", s, array)
 	}