builtin: fix empty string lower / upper assert (#21358)

vlang · Apr 26, 2024 · 5329a0a · 5329a0a
1 parent 712a912
commit 5329a0a
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/vlib/builtin/string.v b/vlib/builtin/string.v
@@ -1524,7 +1524,7 @@ pub fn (s string) to_lower() string {
 // Example: assert 'hello developer'.is_lower() == true
 @[direct_array_access]
 pub fn (s string) is_lower() bool {
-	if s.len > 0 && s[0].is_digit() {
+	if s == '' || s[0].is_digit() {
 		return false
 	}
 	for i in 0 .. s.len {
@@ -1558,7 +1558,7 @@ pub fn (s string) to_upper() string {
 // Example: assert 'HELLO V'.is_upper() == true
 @[direct_array_access]
 pub fn (s string) is_upper() bool {
-	if s.len > 0 && s[0].is_digit() {
+	if s == '' || s[0].is_digit() {
 		return false
 	}
 	for i in 0 .. s.len {

diff --git a/vlib/builtin/string_test.v b/vlib/builtin/string_test.v
@@ -1016,6 +1016,8 @@ fn test_lower() {
 	s = '123'
 	assert !s.is_lower()
 	assert s.to_lower() == '123'
+	s = ''
+	assert !s.is_lower()
 }
 
 fn test_upper() {
@@ -1039,6 +1041,8 @@ fn test_upper() {
 	s = '123'
 	assert !s.is_upper()
 	assert s.to_upper() == '123'
+	s = ''
+	assert !s.is_upper()
 }
 
 fn test_capitalize() {