2 files changed, 21 insertions, 15 deletions

diff --git a/src/bun.js/bindings/JSReadableState.cpp b/src/bun.js/bindings/JSReadableState.cpp
index 309a1ea53..682e681f4 100644
--- a/src/bun.js/bindings/JSReadableState.cpp
+++ b/src/bun.js/bindings/JSReadableState.cpp
@@ -19,7 +19,11 @@ int64_t getHighWaterMark(JSC::VM& vm, JSC::JSGlobalObject* globalObject, bool is
 {
     auto throwScope = DECLARE_THROW_SCOPE(vm);
 
-    if (JSValue highWaterMarkVal = options->getIfPropertyExists(globalObject, PropertyName(JSC::Identifier::fromString(vm, "highWaterMark"_s)))) {
+    // We must use getIfPropertyExists because:
+    // - it might be a getter
+    // - it might be from a super class
+    auto* clientData = WebCore::clientData(vm);
+    if (JSValue highWaterMarkVal = options->getIfPropertyExists(globalObject, clientData->builtinNames().highWaterMarkPublicName())) {
         if (isDuplex && (highWaterMarkVal.isUndefined() || highWaterMarkVal.isNull())) {
             highWaterMarkVal = options->getDirect(vm, JSC::Identifier::fromString(vm, "readableObjectMode"_s));
         }
@@ -45,7 +49,11 @@ void JSReadableState::finishCreation(JSC::VM& vm, JSC::JSGlobalObject* globalObj
             setBool(JSReadableState::Mask::objectMode, true);
     }
 
-    m_highWaterMark = getBool(JSReadableState::Mask::objectMode) ? 16 : 16 * 1024; // default value
+    m_highWaterMark = getBool(
+                          JSReadableState::Mask::objectMode)
+        ? 16
+        : 16 * 1024; // default value
+
     if (options != nullptr) {
         int64_t customHightWaterMark = getHighWaterMark(vm, globalObject, isDuplex, options);
         if (customHightWaterMark >= 0)
@@ -73,8 +81,7 @@ void JSReadableState::finishCreation(JSC::VM& vm, JSC::JSGlobalObject* globalObj
     if (options == nullptr) {
         m_defaultEncoding.set(vm, this, JSC::jsString(vm, WTF::String("utf8"_s)));
     } else {
-        JSC::JSValue defaultEncodingVal = getDirect(vm, JSC::Identifier::fromString(vm, "defaultEncoding"_s));
-        if (defaultEncodingVal) {
+        if (JSC::JSValue defaultEncodingVal = getIfPropertyExists(globalObject, PropertyName(JSC::Identifier::fromString(vm, "defaultEncoding"_s)))) {
             m_defaultEncoding.set(vm, this, defaultEncodingVal);
         } else {
             m_defaultEncoding.set(vm, this, JSC::jsString(vm, WTF::String("utf8"_s)));
@@ -88,7 +95,7 @@ void JSReadableState::finishCreation(JSC::VM& vm, JSC::JSGlobalObject* globalObj
         m_encoding.set(vm, this, JSC::jsNull());
     } else {
         JSC::JSValue encodingVal = options->getDirect(vm, JSC::Identifier::fromString(vm, "encoding"_s));
-        if (encodingVal) {
+        if (encodingVal && encodingVal.isString()) {
             auto constructor = reinterpret_cast<Zig::GlobalObject*>(globalObject)->JSStringDecoder();
             auto constructData = JSC::getConstructData(constructor);
             MarkedArgumentBuffer args;
diff --git a/src/bun.js/bindings/JSReadableState.h b/src/bun.js/bindings/JSReadableState.h
index 544d4b63e..c67baebad 100644
--- a/src/bun.js/bindings/JSReadableState.h
+++ b/src/bun.js/bindings/JSReadableState.h
@@ -11,7 +11,8 @@ class JSReadableState : public JSC::JSDestructibleObject {
 
 public:
     JSReadableState(JSC::VM& vm, JSC::Structure* structure)
-        : Base(vm, structure), m_paused(0)
+        : Base(vm, structure)
+        , m_paused(0)
     {
     }
 
@@ -46,7 +47,7 @@ public:
     void finishCreation(JSC::VM& vm, JSC::JSGlobalObject* globalObject, bool isDuplex, JSObject* options);
     static void destroy(JSCell*) {}
 
-    enum Mask {
+    enum Mask : uint32_t {
         objectMode = 1 << 0,
         emitClose = 1 << 1,
         autoDestroy = 1 << 2,
@@ -57,7 +58,7 @@ public:
         sync = 1 << 7,
         needReadable = 1 << 8,
         emittedReadable = 1 << 9,
-        readableListening = 1<< 10,
+        readableListening = 1 << 10,
         resumeScheduled = 1 << 11,
         errorEmitted = 1 << 12,
         destroyed = 1 << 13,
@@ -68,19 +69,17 @@ public:
         dataEmitted = 1 << 18,
     };
 
-    bool getBool(Mask mask) { return m_bools & mask; }
-    void setBool(Mask mask, bool val) {
-        if (val)
-            m_bools = m_bools | mask;
-        else
-            m_bools = m_bools & mask;
+    constexpr bool getBool(Mask mask) { return m_bools.contains(mask); }
+    constexpr void setBool(Mask mask, bool val)
+    {
+        m_bools.set(mask, val);
     }
 
     // 0 for null, 1 for true, -1 for false
     int8_t m_paused = 0;
     int8_t m_flowing = 0;
 
-    uint32_t m_bools = Mask::constructed | Mask::sync;
+    WTF::OptionSet<Mask> m_bools;
 
     int64_t m_length = 0;
     int64_t m_highWaterMark;