stream writer test: added test for pushing bits

d2common/d2datautils/stream_writer_test.go

@@ -4,6 +4,62 @@ import (
 	"testing"
 )
 
+func TestStreamWriterBits(t *testing.T) {
+	sr := CreateStreamWriter()
+	data := []byte{221, 19}
+
+	for _, i := range data {
+		sr.PushBits(i, bitsPerByte)
+	}
+
+	output := sr.GetBytes()
+	for i, d := range data {
+		if output[i] != d {
+			t.Fatalf("sr.PushBits() pushed %X, but wrote %X instead", d, output[i])
+		}
+	}
+}
+
+func TestStreamWriterBits16(t *testing.T) {
+	sr := CreateStreamWriter()
+	data := []uint16{1024, 19}
+
+	for _, i := range data {
+		sr.PushBits16(i, bitsPerByte*bytesPerint16)
+	}
+
+	output := sr.GetBytes()
+
+	for i, d := range data {
+		outputInt := uint16(output[bytesPerint16*i]) | uint16(output[bytesPerint16*i+1])<<8
+		if outputInt != d {
+			t.Fatalf("sr.PushBits16() pushed %X, but wrote %X instead", d, output[i])
+		}
+	}
+}
+
+func TestStreamWriterBits32(t *testing.T) {
+	sr := CreateStreamWriter()
+	data := []uint32{19324, 87}
+
+	for _, i := range data {
+		sr.PushBits32(i, bitsPerByte*bytesPerint32)
+	}
+
+	output := sr.GetBytes()
+
+	for i, d := range data {
+		outputInt := uint32(output[bytesPerint32*i]) |
+			uint32(output[bytesPerint32*i+1])<<8 |
+			uint32(output[bytesPerint32*i+2])<<16 |
+			uint32(output[bytesPerint32*i+3])<<24
+
+		if outputInt != d {
+			t.Fatalf("sr.PushBits32() pushed %X, but wrote %X instead", d, output[i])
+		}
+	}
+}
+
 func TestStreamWriterByte(t *testing.T) {
 	sr := CreateStreamWriter()
 	data := []byte{0x12, 0x34, 0x56, 0x78}