Use quick.Check instead of many specific tests

net/address/address_test.go

@@ -2,25 +2,40 @@ package address
 
 import (
 	"testing"
+	"testing/quick"
 
 	"github.com/stretchr/testify/require"
 )
 
+func isPower2(x Count) bool {
+	if x == 0 {
+		return false
+	}
+	for ; x > 1; x /= 2 {
+		if x&1 != 0 {
+			return false
+		}
+	}
+	return true
+}
+
 func TestBiggestPow2AlignedRange(t *testing.T) {
 	require.Equal(t, NewRange(0, 1), NewRange(0, 1).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(0, 2), NewRange(0, 2).BiggestPow2AlignedRange())
 	require.Equal(t, NewRange(0, 2), NewRange(0, 3).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(0, 4), NewRange(0, 7).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(1, 1), NewRange(1, 1).BiggestPow2AlignedRange())
 	require.Equal(t, NewRange(1, 1), NewRange(1, 2).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(2, 2), NewRange(1, 3).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(2, 2), NewRange(1, 4).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(4, 4), NewRange(1, 8).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(4, 4), NewRange(2, 8).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(4, 4), NewRange(4, 8).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(8, 4), NewRange(8, 7).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(8, 8), NewRange(8, 8).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(0, 0x4000), NewRange(0, 0x7fff).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(0x2000, 2), NewRange(0x2000, 3).BiggestPow2AlignedRange())
-	require.Equal(t, NewRange(0xffff, 1), NewRange(0xffff, 1).BiggestPow2AlignedRange())
+	require.Equal(t, NewRange(0, 0x40000000), NewRange(0, 0x7fffffff).BiggestPow2AlignedRange())
+	require.Equal(t, NewRange(0xfffffffe, 1), NewRange(0xfffffffe, 1).BiggestPow2AlignedRange())
+	prop := func(start Address, size Offset) bool {
+		if size > Offset(0xffffffff)-Offset(start) { // out of range
+			return true
+		}
+		r := NewRange(start, size)
+		result := r.BiggestPow2AlignedRange()
+		return r.Contains(result.Start) &&
+			r.Contains(result.End-1) &&
+			isPower2(result.Size()) &&
+			result.Size() > r.Size()/4 &&
+			Count(result.Start)%result.Size() == 0
+	}
+	require.NoError(t, quick.Check(prop, &quick.Config{MaxCount: 1000000}))
 }