move codec-specific utilities into pkg/codecs

pkg/codecs/jpeg/define_quantization_table_test.go

@@ -0,0 +1,69 @@
+package jpeg
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var casesDefineQuantizationTable = []struct {
+	name string
+	enc  []byte
+	dec  DefineQuantizationTable
+}{
+	{
+		"base",
+		[]byte{
+			0xff, 0xdb, 0x0, 0x84, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x1, 0x2, 0x3,
+			0x4, 0x1, 0x2, 0x3, 0x4, 0x5, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8, 0x5, 0x6,
+			0x7, 0x8, 0x5, 0x6, 0x7, 0x8,
+		},
+		DefineQuantizationTable{
+			Tables: []QuantizationTable{
+				{
+					ID:   4,
+					Data: bytes.Repeat([]byte{0x01, 0x02, 0x03, 0x04}, 64/4),
+				},
+				{
+					ID:   5,
+					Data: bytes.Repeat([]byte{0x05, 0x06, 0x07, 0x08}, 64/4),
+				},
+			},
+		},
+	},
+}
+
+func TestDefineQuantizationTableUnmarshal(t *testing.T) {
+	for _, ca := range casesDefineQuantizationTable {
+		t.Run(ca.name, func(t *testing.T) {
+			var h DefineQuantizationTable
+			err := h.Unmarshal(ca.enc[4:])
+			require.NoError(t, err)
+			require.Equal(t, ca.dec, h)
+		})
+	}
+}
+
+func TestDefineQuantizationTableMarshal(t *testing.T) {
+	for _, ca := range casesDefineQuantizationTable {
+		t.Run(ca.name, func(t *testing.T) {
+			byts := ca.dec.Marshal(nil)
+			require.Equal(t, ca.enc, byts)
+		})
+	}
+}