assert len > 0

core/collection/ring.go

@@ -6,6 +6,10 @@ type Ring struct {
 }
 
 func NewRing(n int) *Ring {
+	if n < 1 {
+		panic("n should be greater than 0")
+	}
+
 	return &Ring{
 		elements: make([]interface{}, n),
 	}

core/collection/ring_test.go

@@ -6,6 +6,12 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestNewRing(t *testing.T) {
+	assert.Panics(t, func() {
+		NewRing(0)
+	})
+}
+
 func TestRingLess(t *testing.T) {
 	ring := NewRing(5)
 	for i := 0; i < 3; i++ {