fix: strings.Index panic

Changes.md

@@ -1,3 +1,7 @@
+## WIP  TBD
+
+ * :hammer: Fixed buf in `strings.Indent` that caused a panic if the input string was empty.
+
 ## v0.9.0  2024-09-03
 
  * Adding `maps.Flip`, `maps.FlipSlice`, and `sets.FlipMap`.

strings/content.go

@@ -286,7 +286,7 @@ func Increment(input string) string {
 // Indent returns the string with each line indented by the given string.
 func Indent(s, indent string) string {
 	startIndent := indent
-	if s[0] == '\n' {
+	if len(s) > 0 && s[0] == '\n' {
 		startIndent = ""
 	}
 	return strings.TrimRight(

strings/content_test.go

@@ -93,6 +93,7 @@ func TestIncrement(t *testing.T) {
 func TestIndent(t *testing.T) {
 	t.Parallel()
 
+	assert.Equal(t, "", strings.Indent("", "    "))
 	assert.Equal(t, "\n    a\n    b\n    c\n", strings.Indent("\na\nb\nc\n", "    "))
 	assert.Equal(t, "    a\n    b\n    c", strings.Indent("a\nb\nc", "    "))
 }