code review: int and uint are either 32 or 64 bits

metrics.go

@@ -28,14 +28,16 @@ const (
 //go:generate stringer -type=MetricType
 
 func (m MetricType) isCompatibleInt(val int) bool {
-	switch {
-	case val < 0:
+	switch v := int64(val); {
+	case v < math.MinInt32:
+		return m == Int64Type
+	case v < 0:
 		return m == Int32Type || m == Int64Type
-	case val <= math.MaxInt32:
+	case v <= math.MaxInt32:
 		return m == Int32Type || m == Int64Type || m == Uint32Type || m == Uint64Type
-	case uint32(val) <= math.MaxUint32:
+	case v <= math.MaxUint32:
 		return m == Int64Type || m == Uint32Type || m == Uint64Type
-	case int64(val) <= math.MaxInt64:
+	case v <= math.MaxInt64:
 		return m == Int64Type || m == Uint64Type
 	default:
 		return false

metrics_amd64_test.go

@@ -0,0 +1,26 @@
+package speed
+
+import (
+	"math"
+	"testing"
+)
+
+func TestIsCompatible64(t *testing.T) {
+	cases := []struct {
+		t      MetricType
+		v      interface{}
+		result bool
+	}{
+		{Int32Type, math.MinInt32 - 1, false},
+		{Int32Type, math.MinInt64, false},
+		{Uint32Type, math.MaxUint32 + 1, false},
+		{Uint32Type, math.MaxInt64, false},
+	}
+
+	for _, c := range cases {
+		r := c.t.IsCompatible(c.v)
+		if r != c.result {
+			t.Errorf("%v.IsCompatible(%v(%T)) should be %v, not %v", c.t, c.v, c.v, c.result, r)
+		}
+	}
+}