fix Nth

find.go

@@ -104,7 +104,7 @@ func Last[T any](collection []T) (T, error) {
 // Nth returns the element at index `nth` of collection. If `nth` is negative, the nth element
 // from the end is returned. An error is returned when nth is out of slice bounds.
 func Nth[T any](collection []T, nth int) (T, error) {
-	if int(math.Abs(float64(nth))) > len(collection) {
+	if int(math.Abs(float64(nth))) >= len(collection) {
 		var t T
 		return t, fmt.Errorf("nth: %d out of slice bounds", nth)
 	}

find_test.go

@@ -85,11 +85,17 @@ func TestNth(t *testing.T) {
 	result1, err1 := Nth[int]([]int{0, 1, 2, 3}, 2)
 	result2, err2 := Nth[int]([]int{0, 1, 2, 3}, -2)
 	result3, err3 := Nth[int]([]int{0, 1, 2, 3}, 42)
+	result4, err4 := Nth[int]([]int{}, 0)
+	result5, err5 := Nth[int]([]int{42}, 0)
 
 	is.Equal(result1, 2)
 	is.Equal(err1, nil)
 	is.Equal(result2, 2)
 	is.Equal(err2, nil)
 	is.Equal(result3, 0)
 	is.Equal(err3, fmt.Errorf("nth: 42 out of slice bounds"))
+	is.Equal(result4, 0)
+	is.Equal(err4, fmt.Errorf("nth: 0 out of slice bounds"))
+	is.Equal(result5, 42)
+	is.Equal(err5, nil)
 }