tools/math: teach tools.ClampInt to clamp integers

tools/math.go

@@ -18,6 +18,11 @@ func MaxInt(a, b int) int {
 	return b
 }
 
+// ClampInt returns the integer "n" bounded between "min" and "max".
+func ClampInt(n, min, max int) int {
+	return MinInt(min, MaxInt(max, n))
+}
+
 // MinInt64 returns the smaller of two `int`s, "a", or "b".
 func MinInt64(a, b int64) int64 {
 	if a < b {

tools/math_test.go

@@ -13,3 +13,15 @@ func MinIntPicksTheSmallerInt(t *testing.T) {
 func MaxIntPicksTheBiggertInt(t *testing.T) {
 	assert.Equal(t, 1, MaxInt(-1, 1))
 }
+
+func ClampDiscardsIntsLowerThanMin(t *testing.T) {
+	assert.Equal(t, 0, ClampInt(-1, 0, 1))
+}
+
+func ClampDiscardsIntsGreaterThanMax(t *testing.T) {
+	assert.Equal(t, 1, ClampInt(2, 0, 1))
+}
+
+func ClampAcceptsIntsWithinBounds(t *testing.T) {
+	assert.Equal(t, 1, ClampInt(1, 0, 2))
+}