test(logic): put MultiplyUint64Overflow under test

x/logic/meter/weighted_meter_test.go

@@ -0,0 +1,41 @@
+package meter
+
+import (
+	"fmt"
+	"math"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestMultiplyUint64Overflow(t *testing.T) {
+	Convey("Given test cases", t, func() {
+		testCases := []struct {
+			a            uint64
+			b            uint64
+			wantResult   uint64
+			wantOverflow bool
+		}{
+			{0, 0, 0, false},
+			{0, 1, 0, false},
+			{1, 0, 0, false},
+			{1, 1, 1, false},
+			{1, math.MaxUint64, math.MaxUint64, false},
+			{math.MaxUint64, 1, math.MaxUint64, false},
+			{2, math.MaxUint64, 0, true},
+			{math.MaxUint64, 2, 0, true},
+			{math.MaxUint64, math.MaxUint64, 0, true},
+		}
+
+		for _, tc := range testCases {
+			Convey(fmt.Sprintf("When calling the multiplyUint64Overflow(%d, %d)", tc.a, tc.b), func() {
+				actual, overflow := multiplyUint64Overflow(tc.a, tc.b)
+
+				Convey("Then we should get ()", func() {
+					So(overflow, ShouldEqual, tc.wantOverflow)
+					So(actual, ShouldEqual, tc.wantResult)
+				})
+			})
+		}
+	})
+}