bit_writer_test.go

package gorilla

import (
	"bytes"
	"encoding/binary"
	"testing"

	fuzz "github.com/google/gofuzz"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func Test_bitWriter_writeBit(t *testing.T) {
	tests := []struct {
		name   string
		binary string
		hex    uint8
	}{
		{
			name:   "write 1",
			binary: "00000001",
			hex:    0x1,
		},
		{
			name:   "write 8",
			binary: "00001000",
			hex:    0x8,
		},
		{
			name:   "write 113",
			binary: "01110001",
			hex:    0x71,
		},
		{
			name:   "write 255",
			binary: "11111111",
			hex:    0xff,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			buf := new(bytes.Buffer)
			bw := newBitWriter(buf)
			for i := 0; i < len(tt.binary); i++ {
				var err error
				if tt.binary[i] == '1' {
					err = bw.writeBit(one)
				} else {
					err = bw.writeBit(zero)
				}
				require.Nil(t, err)
			}
			assert.Equal(t, tt.hex, buf.Bytes()[0])
		})
	}
}

func Test_bitWriter_writeBits(t *testing.T) {
	f := fuzz.New().NilChance(0)

	for i := 0; i < 10; i++ {
		var u64 uint64
		f.Fuzz(&u64)

		buf := new(bytes.Buffer)
		bw := newBitWriter(buf)
		require.Nil(t, bw.writeBits(u64, 64))

		wantBytes := make([]byte, 8)
		binary.BigEndian.PutUint64(wantBytes, u64)

		assert.Equal(t, wantBytes, buf.Bytes())
	}
}

func Test_bitWriter_writeByte(t *testing.T) {
	var b byte = 0x1
	for i := 0; i < 256; i++ {
		buf := new(bytes.Buffer)
		require.Nil(t, buf.WriteByte(b))
		bw := newBitWriter(buf)
		require.Nil(t, bw.writeByte(b))
		assert.Equal(t, b, buf.Bytes()[0])
		b++
	}
}