From 497ea02745d1c34f21f78f5708e21a0f53bb3dc9 Mon Sep 17 00:00:00 2001
From: aalu1418 <50029043+aalu1418@users.noreply.github.com>
Date: Mon, 22 Apr 2024 15:35:35 -0600
Subject: [PATCH] allow signed + unsigned = integers

---
 pkg/utils/mathutil/mathutil.go      |  8 +++++---
 pkg/utils/mathutil/mathutil_test.go | 17 ++++++++++-------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/pkg/utils/mathutil/mathutil.go b/pkg/utils/mathutil/mathutil.go
index 370fe871f..4c7da09f0 100644
--- a/pkg/utils/mathutil/mathutil.go
+++ b/pkg/utils/mathutil/mathutil.go
@@ -2,6 +2,7 @@ package mathutil
 
 import (
 	"fmt"
+	"math"
 
 	"golang.org/x/exp/constraints"
 )
@@ -26,15 +27,16 @@ func Min[V constraints.Ordered](first V, vals ...V) V {
 	return min
 }
 
-func Avg[V constraints.Unsigned](arr []V) (V, error) {
+func Avg[V constraints.Integer](arr ...V) (V, error) {
 	total := V(0)
 
 	for _, v := range arr {
 		prev := total
 		total += v
 
-		// check addition overflow
-		if total < prev {
+		// check addition overflow (positive + negative)
+		if (total < prev && !math.Signbit(float64(v))) ||
+			(total > prev && math.Signbit(float64(v))) {
 			return 0, fmt.Errorf("overflow: addition %T", V(0))
 		}
 	}
diff --git a/pkg/utils/mathutil/mathutil_test.go b/pkg/utils/mathutil/mathutil_test.go
index ab3c796bf..8ef63510b 100644
--- a/pkg/utils/mathutil/mathutil_test.go
+++ b/pkg/utils/mathutil/mathutil_test.go
@@ -2,6 +2,7 @@ package mathutil
 
 import (
 	"fmt"
+	"math"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -35,21 +36,23 @@ func TestMin(t *testing.T) {
 
 func TestAvg(t *testing.T) {
 	// happy path
-	r, err := Avg([]uint8{1, 2, 3})
+	r, err := Avg(int8(1), -2, 4)
 	assert.NoError(t, err)
-	assert.Equal(t, uint8(2), r)
+	assert.Equal(t, int8(1), r)
 
 	// single element
-	r, err = Avg([]uint8{0})
+	r, err = Avg(int8(0))
 	assert.NoError(t, err)
-	assert.Equal(t, uint8(0), r)
+	assert.Equal(t, int8(0), r)
 
 	// overflow addition
-	r, err = Avg([]uint8{255, 1})
+	r, err = Avg(int8(math.MaxInt8), 1)
+	assert.ErrorContains(t, err, fmt.Sprintf("overflow: addition"))
+	r, err = Avg(int8(math.MinInt8), -1)
 	assert.ErrorContains(t, err, fmt.Sprintf("overflow: addition"))
 
 	// overflow length
-	a := make([]uint8, 256)
-	r, err = Avg(a)
+	a := make([]int8, 256)
+	r, err = Avg(a...)
 	assert.ErrorContains(t, err, "overflow: array len")
 }