Add gzip codec (#200)

builtins/codecs.go

@@ -2,13 +2,15 @@ package builtins
 
 import (
 	"bytes"
+	"compress/gzip"
 	"context"
 	"encoding/base32"
 	"encoding/base64"
 	"encoding/csv"
 	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"io"
 	"net/url"
 	"sort"
 	"sync"
@@ -37,6 +39,7 @@ func init() {
 	RegisterCodec("yaml", &Codec{Encode: encodeYAML, Decode: decodeYAML})
 	RegisterCodec("csv", &Codec{Encode: encodeCsv, Decode: decodeCsv})
 	RegisterCodec("urlquery", &Codec{Encode: encodeUrlQuery, Decode: decodeUrlQuery})
+	RegisterCodec("gzip", &Codec{Encode: encodeGzip, Decode: decodeGzip})
 }
 
 // RegisterCodec registers a new codec
@@ -78,6 +81,22 @@ func Encode(ctx context.Context, args ...object.Object) object.Object {
 	return codec.Encode(ctx, args[0])
 }
 
+func encodeGzip(ctx context.Context, obj object.Object) object.Object {
+	data, err := object.AsBytes(obj)
+	if err != nil {
+		return err
+	}
+	var buf bytes.Buffer
+	writer := gzip.NewWriter(&buf)
+	if _, err := writer.Write(data); err != nil {
+		return object.NewError(err)
+	}
+	if err := writer.Close(); err != nil {
+		return object.NewError(err)
+	}
+	return object.NewByteSlice(buf.Bytes())
+}
+
 func encodeBase64(ctx context.Context, obj object.Object) object.Object {
 	data, err := object.AsBytes(obj)
 	if err != nil {
@@ -231,6 +250,23 @@ func Decode(ctx context.Context, args ...object.Object) object.Object {
 	return codec.Decode(ctx, args[0])
 }
 
+func decodeGzip(ctx context.Context, obj object.Object) object.Object {
+	data, errObj := object.AsBytes(obj)
+	if errObj != nil {
+		return errObj
+	}
+	reader := bytes.NewReader(data)
+	gzreader, err := gzip.NewReader(reader)
+	if err != nil {
+		return object.NewError(err)
+	}
+	output, err := io.ReadAll(gzreader)
+	if err != nil {
+		return object.NewError(err)
+	}
+	return object.NewByteSlice(output)
+}
+
 func decodeBase64(ctx context.Context, obj object.Object) object.Object {
 	data, err := object.AsBytes(obj)
 	if err != nil {

builtins/codecs_test.go

@@ -0,0 +1,57 @@
+package builtins
+
+import (
+	"context"
+	"testing"
+
+	"github.com/risor-io/risor/object"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBinaryCodecs(t *testing.T) {
+	codecs := []string{
+		"base64",
+		"base32",
+		"hex",
+		"gzip",
+	}
+	ctx := context.Background()
+	value := "Farfalle"
+	for _, codec := range codecs {
+		codecName := object.NewString(codec)
+		t.Run(codec, func(t *testing.T) {
+			encoded := Encode(ctx, object.NewString(value), codecName)
+			if errObj, ok := encoded.(*object.Error); ok {
+				t.Fatalf("encoding error: %v", errObj)
+			}
+			decoded := Decode(ctx, encoded, codecName)
+			if errObj, ok := decoded.(*object.Error); ok {
+				t.Fatalf("decoding error: %v", errObj)
+			}
+			require.Equal(t, object.NewByteSlice([]byte(value)), decoded)
+		})
+	}
+}
+
+func TestUnknownCodec(t *testing.T) {
+	ctx := context.Background()
+	encoded := Encode(ctx, object.NewString("oops"), object.NewString("unknown"))
+	errObj, ok := encoded.(*object.Error)
+	require.True(t, ok)
+	require.Equal(t, "codec not found: unknown", errObj.Value().Error())
+}
+
+func TestJsonCodec(t *testing.T) {
+	ctx := context.Background()
+	value := "thumbs up 👍🏼"
+	encoded := Encode(ctx, object.NewString(value), object.NewString("json"))
+	if errObj, ok := encoded.(*object.Error); ok {
+		t.Fatalf("encoding error: %v", errObj)
+	}
+	require.Equal(t, object.NewString("\""+value+"\""), encoded)
+	decoded := Decode(ctx, encoded, object.NewString("json"))
+	if errObj, ok := decoded.(*object.Error); ok {
+		t.Fatalf("decoding error: %v", errObj)
+	}
+	require.Equal(t, object.NewString(value), decoded)
+}