Add support for ArrayBuffer in k6/encoding

This is a breaking change.

Part of #1020

js/modules/k6/encoding/encoding.go

@@ -24,6 +24,8 @@ import (
 	"context"
 	"encoding/base64"
 
+	"github.com/dop251/goja"
+
 	"github.com/loadimpact/k6/js/common"
 	"github.com/loadimpact/k6/js/internal/modules"
 )
@@ -38,26 +40,37 @@ func New() *Encoding {
 	return &Encoding{}
 }
 
-func (e *Encoding) B64encode(ctx context.Context, input []byte, encoding string) string {
+// B64encode returns the base64 encoding of input as a string.
+// The data type of input can be a string, []byte or ArrayBuffer.
+func (e *Encoding) B64encode(ctx context.Context, input interface{}, encoding string) string {
+	data, err := common.ToBytes(input)
+	if err != nil {
+		common.Throw(common.GetRuntime(ctx), err)
+	}
 	switch encoding {
 	case "rawstd":
-		return base64.StdEncoding.WithPadding(base64.NoPadding).EncodeToString(input)
+		return base64.StdEncoding.WithPadding(base64.NoPadding).EncodeToString(data)
 	case "std":
-		return base64.StdEncoding.EncodeToString(input)
+		return base64.StdEncoding.EncodeToString(data)
 	case "rawurl":
-		return base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(input)
+		return base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(data)
 	case "url":
-		return base64.URLEncoding.EncodeToString(input)
+		return base64.URLEncoding.EncodeToString(data)
 	default:
-		return base64.StdEncoding.EncodeToString(input)
+		return base64.StdEncoding.EncodeToString(data)
 	}
 }
 
-func (e *Encoding) B64decode(ctx context.Context, input string, encoding string) string {
-	var output []byte
-	var err error
+// B64decode returns the decoded data of the base64 encoded input string in the
+// given format, wrapped in an ArrayBuffer.
+func (e *Encoding) B64decode(ctx context.Context, input, format string) *goja.ArrayBuffer {
+	var (
+		output []byte
+		err    error
+		rt     = common.GetRuntime(ctx)
+	)
 
-	switch encoding {
+	switch format {
 	case "rawstd":
 		output, err = base64.StdEncoding.WithPadding(base64.NoPadding).DecodeString(input)
 	case "std":
@@ -71,8 +84,9 @@ func (e *Encoding) B64decode(ctx context.Context, input string, encoding string)
 	}
 
 	if err != nil {
-		common.Throw(common.GetRuntime(ctx), err)
+		common.Throw(rt, err)
 	}
 
-	return string(output)
+	ab := rt.NewArrayBuffer(output)
+	return &ab
 }

js/modules/k6/encoding/encoding_test.go

@@ -55,8 +55,19 @@ func TestEncodingAlgorithms(t *testing.T) {
 			_, err := common.RunString(rt, `
 			var correct = "hello world";
 			var decoded = encoding.b64decode("aGVsbG8gd29ybGQ=");
-			if (decoded !== correct) {
-				throw new Error("Decoding mismatch: " + decoded);
+			var decStr = String.fromCharCode.apply(null, new Uint8Array(decoded));
+			if (decStr !== correct) {
+				throw new Error("Decoding mismatch: " + decStr);
+			}`)
+			assert.NoError(t, err)
+		})
+		t.Run("DefaultArrayBufferEnc", func(t *testing.T) {
+			_, err := common.RunString(rt, `
+			var exp = "aGVsbG8=";
+			var input = new Uint8Array([104, 101, 108, 108, 111]); // "hello"
+			var encoded = encoding.b64encode(input.buffer);
+			if (encoded !== exp) {
+				throw new Error("Encoding mismatch: " + encoded);
 			}`)
 			assert.NoError(t, err)
 		})
@@ -73,8 +84,10 @@ func TestEncodingAlgorithms(t *testing.T) {
 			_, err := common.RunString(rt, `
 			var correct = "こんにちは世界";
 			var decoded = encoding.b64decode("44GT44KT44Gr44Gh44Gv5LiW55WM");
-			if (decoded !== correct) {
-				throw new Error("Decoding mismatch: " + decoded);
+			var decStr = String.fromCharCode.apply(null, new Uint8Array(decoded));
+			var decStrUtf8 = decodeURIComponent(escape(decStr));
+			if (decStrUtf8 !== correct) {
+				throw new Error("Encoding mismatch: " + decStr);
 			}`)
 			assert.NoError(t, err)
 		})
@@ -91,8 +104,10 @@ func TestEncodingAlgorithms(t *testing.T) {
 			_, err := common.RunString(rt, `
 			var correct = "hello world";
 			var decoded = encoding.b64decode("aGVsbG8gd29ybGQ=", "std");
-			if (decoded !== correct) {
-				throw new Error("Decoding mismatch: " + decoded);
+			var decStr = String.fromCharCode.apply(null, new Uint8Array(decoded));
+			var decStrUtf8 = decodeURIComponent(escape(decStr));
+			if (decStrUtf8 !== correct) {
+				throw new Error("Decoding mismatch: " + decStrUtf8);
 			}`)
 			assert.NoError(t, err)
 		})
@@ -109,8 +124,10 @@ func TestEncodingAlgorithms(t *testing.T) {
 			_, err := common.RunString(rt, `
 			var correct = "hello world";
 			var decoded = encoding.b64decode("aGVsbG8gd29ybGQ", "rawstd");
-			if (decoded !== correct) {
-				throw new Error("Decoding mismatch: " + decoded);
+			var decStr = String.fromCharCode.apply(null, new Uint8Array(decoded));
+			var decStrUtf8 = decodeURIComponent(escape(decStr));
+			if (decStrUtf8 !== correct) {
+				throw new Error("Decoding mismatch: " + decStrUtf8);
 			}`)
 			assert.NoError(t, err)
 		})
@@ -127,8 +144,10 @@ func TestEncodingAlgorithms(t *testing.T) {
 			_, err := common.RunString(rt, `
 			var correct = "小飼弾..";
 			var decoded = encoding.b64decode("5bCP6aO85by-Li4=", "url");
-			if (decoded !== correct) {
-				throw new Error("Decoding mismatch: " + decoded);
+			var decStr = String.fromCharCode.apply(null, new Uint8Array(decoded));
+			var decStrUtf8 = decodeURIComponent(escape(decStr));
+			if (decStrUtf8 !== correct) {
+				throw new Error("Decoding mismatch: " + decStrUtf8);
 			}`)
 			assert.NoError(t, err)
 		})
@@ -145,8 +164,10 @@ func TestEncodingAlgorithms(t *testing.T) {
 			_, err := common.RunString(rt, `
 			var correct = "小飼弾..";
 			var decoded = encoding.b64decode("5bCP6aO85by-Li4", "rawurl");
-			if (decoded !== correct) {
-				throw new Error("Decoding mismatch: " + decoded);
+			var decStr = String.fromCharCode.apply(null, new Uint8Array(decoded));
+			var decStrUtf8 = decodeURIComponent(escape(decStr));
+			if (decStrUtf8 !== correct) {
+				throw new Error("Decoding mismatch: " + decStrUtf8);
 			}`)
 			assert.NoError(t, err)
 		})