Fix `Buffer.from` to handle double-byte hex encoding strings (#4933)

Close: #4919

2 files changed, 14 insertions, 0 deletions

diff --git a/src/bun.js/bindings/JSBuffer.cpp b/src/bun.js/bindings/JSBuffer.cpp
index ad901b0e4..9227e47b3 100644
--- a/src/bun.js/bindings/JSBuffer.cpp
+++ b/src/bun.js/bindings/JSBuffer.cpp
@@ -351,6 +351,7 @@ static EncodedJSValue constructFromEncoding(JSGlobalObject* lexicalGlobalObject,
         case WebCore::BufferEncodingType::utf8:
         case WebCore::BufferEncodingType::base64:
         case WebCore::BufferEncodingType::base64url:
+        case WebCore::BufferEncodingType::hex:
         case WebCore::BufferEncodingType::ascii:
         case WebCore::BufferEncodingType::latin1: {
             result = Bun__encoding__constructFromUTF16(lexicalGlobalObject, view.characters16(), view.length(), static_cast<uint8_t>(encoding));
diff --git a/test/js/node/buffer.test.js b/test/js/node/buffer.test.js
index 7c3d16536..afc9cdee8 100644
--- a/test/js/node/buffer.test.js
+++ b/test/js/node/buffer.test.js
@@ -2572,3 +2572,16 @@ it("construct buffer from UTF16, issue #3914", () => {
   const buf = Buffer.from(str, "latin1");
   expect(buf).toStrictEqual(raw);
 });
+
+it("construct buffer from hex, issue #4919", () => {
+  const data = "测试63e9f6c4b04fa8c80f3fb0ee";
+
+  const slice1 = data.substring(0, 2);
+  const slice2 = data.substring(2);
+
+  const buf1 = Buffer.from(slice1, "hex");
+  const buf2 = Buffer.from(slice2, "hex");
+
+  expect(buf1).toStrictEqual(Buffer.from([]));
+  expect(buf2).toStrictEqual(Buffer.from([0x63, 0xe9, 0xf6, 0xc4, 0xb0, 0x4f, 0xa8, 0xc8, 0x0f, 0x3f, 0xb0, 0xee]));
+});