Added new OrElseNilSafe to handle nil pointers for optional strings. (#…

…199)

README.md

@@ -1417,6 +1417,7 @@ func BlankOr(val, defVal string) string
 func ZeroOr[T ~string](val, defVal T) T
 func ErrorOr(s string, err error, defVal string) string
 func OrElse(s, orVal string) string
+func OrElseNilSafe(s *string, orVal string) string
 func OrHandle(s string, fn comdef.StringHandleFunc) string
 func Valid(ss ...string) string
 func Replaces(str string, pairs map[string]string) string

README.zh-CN.md

@@ -1418,6 +1418,7 @@ func BlankOr(val, defVal string) string
 func ZeroOr[T ~string](val, defVal T) T
 func ErrorOr(s string, err error, defVal string) string
 func OrElse(s, orVal string) string
+func OrElseNilSafe(s *string, orVal string) string
 func OrHandle(s string, fn comdef.StringHandleFunc) string
 func Valid(ss ...string) string
 func Replaces(str string, pairs map[string]string) string

strutil/strutil.go

@@ -51,6 +51,14 @@ func OrElse(s, orVal string) string {
 	return orVal
 }
 
+// OrElseNilSafe return default value on s is nil, otherwise return s
+func OrElseNilSafe(s *string, orVal string) string {
+	if s == nil || *s == "" {
+		return orVal
+	}
+	return *s
+}
+
 // OrHandle return fn(s) on s is not empty.
 func OrHandle(s string, fn comdef.StringHandleFunc) string {
 	if s != "" {

strutil/strutil_test.go

@@ -25,6 +25,12 @@ func TestValid(t *testing.T) {
 	is.Eq("cd", strutil.OrElse("", "cd"))
 	is.Eq("ab", strutil.OrElse("ab", "cd"))
 
+	var str = "non-empty"
+	is.Equal(str, strutil.OrElseNilSafe(&str, "fallback"))
+	str = ""
+	is.Equal("fallback", strutil.OrElseNilSafe(&str, "fallback"))
+	is.Equal("default", strutil.OrElseNilSafe(nil, "default"))
+
 	is.Eq(" ", strutil.ZeroOr(" ", "cd"))
 	is.Eq("cd", strutil.ZeroOr("", "cd"))
 	is.Eq("ab", strutil.ZeroOr("ab", "cd"))