[Bugfix]: Out of range percentile calculations

It was possible for a user of percentile-calculation functions to
request a percentile that caused the underlying array of values to be
accessed out of bounds. This patch fixes that error.

Signed-off-by: Will Hawkins <[email protected]>

1 files changed, 6 insertions, 3 deletions

diff --git a/utilities/math.go b/utilities/math.go
index 1ecca61..96b9f10 100644
--- a/utilities/math.go
+++ b/utilities/math.go
@@ -36,15 +36,18 @@ func CalculateAverage[T Number](elements []T) float64 {
 
 func CalculatePercentile[T Number](
 	elements []T,
-	p int,
+	p uint,
 ) (result T) {
 	result = T(0)
-	if p < 0 || p > 100 {
+	if p < 1 || p > 100 {
 		return
 	}
 
 	sort.Slice(elements, func(l int, r int) bool { return elements[l] < elements[r] })
-	pindex := int64((float64(p) / float64(100)) * float64(len(elements)))
+	pindex := int((float64(p) / float64(100)) * float64(len(elements)))
+	if pindex >= len(elements) {
+		return
+	}
 	result = elements[pindex]
 	return
 }