👔 up(str): update some string util comments and func

strutil/check.go

@@ -57,12 +57,12 @@ func BytePos(s string, bt byte) int {
 }
 
 // IEqual ignore case check given two string is equals.
-func IEqual(s1 string, s2 string) bool {
-	return strings.ToLower(s1) == strings.ToLower(s2)
+func IEqual(s1, s2 string) bool {
+	return strings.EqualFold(s1, s2)
 }
 
 // IContains ignore case check substr in the given string.
-func IContains(s string, sub string) bool {
+func IContains(s, sub string) bool {
 	return strings.Contains(strings.ToLower(s), strings.ToLower(sub))
 }
 

strutil/convert.go

@@ -17,7 +17,9 @@ import (
 )
 
 var (
-	ErrDateLayout   = errors.New("invalid date layout string")
+	// ErrDateLayout error
+	ErrDateLayout = errors.New("invalid date layout string")
+	// ErrInvalidParam error
 	ErrInvalidParam = errors.New("invalid input parameter")
 
 	// some regex for convert string.