First commit

bit_array_test.go

@@ -0,0 +1,120 @@
+package common
+
+import (
+	"testing"
+)
+
+func randBitArray(bits int) (*BitArray, []byte) {
+	src := RandBytes((bits + 7) / 8)
+	bA := NewBitArray(bits)
+	for i := 0; i < len(src); i++ {
+		for j := 0; j < 8; j++ {
+			if i*8+j >= bits {
+				return bA, src
+			}
+			setBit := src[i]&(1<<uint(j)) > 0
+			bA.SetIndex(i*8+j, setBit)
+		}
+	}
+	return bA, src
+}
+
+func TestAnd(t *testing.T) {
+
+	bA1, _ := randBitArray(51)
+	bA2, _ := randBitArray(31)
+	bA3 := bA1.And(bA2)
+
+	if bA3.Bits != 31 {
+		t.Error("Expected min bits", bA3.Bits)
+	}
+	if len(bA3.Elems) != len(bA2.Elems) {
+		t.Error("Expected min elems length")
+	}
+	for i := 0; i < bA3.Bits; i++ {
+		expected := bA1.GetIndex(i) && bA2.GetIndex(i)
+		if bA3.GetIndex(i) != expected {
+			t.Error("Wrong bit from bA3", i, bA1.GetIndex(i), bA2.GetIndex(i), bA3.GetIndex(i))
+		}
+	}
+}
+
+func TestOr(t *testing.T) {
+
+	bA1, _ := randBitArray(51)
+	bA2, _ := randBitArray(31)
+	bA3 := bA1.Or(bA2)
+
+	if bA3.Bits != 51 {
+		t.Error("Expected max bits")
+	}
+	if len(bA3.Elems) != len(bA1.Elems) {
+		t.Error("Expected max elems length")
+	}
+	for i := 0; i < bA3.Bits; i++ {
+		expected := bA1.GetIndex(i) || bA2.GetIndex(i)
+		if bA3.GetIndex(i) != expected {
+			t.Error("Wrong bit from bA3", i, bA1.GetIndex(i), bA2.GetIndex(i), bA3.GetIndex(i))
+		}
+	}
+}
+
+func TestSub1(t *testing.T) {
+
+	bA1, _ := randBitArray(31)
+	bA2, _ := randBitArray(51)
+	bA3 := bA1.Sub(bA2)
+
+	if bA3.Bits != bA1.Bits {
+		t.Error("Expected bA1 bits")
+	}
+	if len(bA3.Elems) != len(bA1.Elems) {
+		t.Error("Expected bA1 elems length")
+	}
+	for i := 0; i < bA3.Bits; i++ {
+		expected := bA1.GetIndex(i)
+		if bA2.GetIndex(i) {
+			expected = false
+		}
+		if bA3.GetIndex(i) != expected {
+			t.Error("Wrong bit from bA3", i, bA1.GetIndex(i), bA2.GetIndex(i), bA3.GetIndex(i))
+		}
+	}
+}
+
+func TestSub2(t *testing.T) {
+
+	bA1, _ := randBitArray(51)
+	bA2, _ := randBitArray(31)
+	bA3 := bA1.Sub(bA2)
+
+	if bA3.Bits != bA1.Bits {
+		t.Error("Expected bA1 bits")
+	}
+	if len(bA3.Elems) != len(bA1.Elems) {
+		t.Error("Expected bA1 elems length")
+	}
+	for i := 0; i < bA3.Bits; i++ {
+		expected := bA1.GetIndex(i)
+		if i < bA2.Bits && bA2.GetIndex(i) {
+			expected = false
+		}
+		if bA3.GetIndex(i) != expected {
+			t.Error("Wrong bit from bA3")
+		}
+	}
+}
+
+func TestPickRandom(t *testing.T) {
+	for idx := 0; idx < 123; idx++ {
+		bA1 := NewBitArray(123)
+		bA1.SetIndex(idx, true)
+		index, ok := bA1.PickRandom()
+		if !ok {
+			t.Fatal("Expected to pick element but got none")
+		}
+		if index != idx {
+			t.Fatalf("Expected to pick element at %v but got wrong index", idx)
+		}
+	}
+}