Revert "refactor: update runtime code for primordial checks for "instanceof" (#13497)" (#13511)

This reverts commit 884143218fad0e18f7553aaf079d52de703f7601.

10 files changed, 166 insertions, 278 deletions

diff --git a/ext/web/01_dom_exception.js b/ext/web/01_dom_exception.js
index a3beb3064..44aa72abe 100644
--- a/ext/web/01_dom_exception.js
+++ b/ext/web/01_dom_exception.js
@@ -16,7 +16,6 @@
     ErrorPrototype,
     ObjectDefineProperty,
     ObjectEntries,
-    ObjectPrototypeIsPrototypeOf,
     ObjectSetPrototypeOf,
     SymbolFor,
   } = window.__bootstrap.primordials;
@@ -127,7 +126,7 @@
     }
 
     [SymbolFor("Deno.customInspect")](inspect) {
-      if (ObjectPrototypeIsPrototypeOf(DOMExceptionPrototype, this)) {
+      if (this instanceof DOMException) {
         return `DOMException: ${this.#message}`;
       } else {
         return inspect(consoleInternal.createFilteredInspectProxy({
@@ -146,7 +145,6 @@
   ObjectSetPrototypeOf(DOMException.prototype, ErrorPrototype);
 
   webidl.configurePrototype(DOMException);
-  const DOMExceptionPrototype = DOMException.prototype;
 
   for (
     const [key, value] of ObjectEntries({
diff --git a/ext/web/02_event.js b/ext/web/02_event.js
index b32bb01b8..7ba5afa27 100644
--- a/ext/web/02_event.js
+++ b/ext/web/02_event.js
@@ -29,7 +29,6 @@
     ObjectCreate,
     ObjectDefineProperty,
     ObjectGetOwnPropertyDescriptor,
-    ObjectPrototypeIsPrototypeOf,
     ReflectDefineProperty,
     Symbol,
     SymbolFor,
@@ -175,7 +174,7 @@
     [SymbolFor("Deno.privateCustomInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(Event.prototype, this),
+        evaluate: this instanceof Event,
         keys: EVENT_PROPS,
       }));
     }
@@ -1059,7 +1058,7 @@
     [SymbolFor("Deno.privateCustomInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(ErrorEvent.prototype, this),
+        evaluate: this instanceof ErrorEvent,
         keys: [
           ...EVENT_PROPS,
           "message",
@@ -1120,7 +1119,7 @@
     [SymbolFor("Deno.privateCustomInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(CloseEvent.prototype, this),
+        evaluate: this instanceof CloseEvent,
         keys: [
           ...EVENT_PROPS,
           "wasClean",
@@ -1152,7 +1151,7 @@
     [SymbolFor("Deno.privateCustomInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(MessageEvent.prototype, this),
+        evaluate: this instanceof MessageEvent,
         keys: [
           ...EVENT_PROPS,
           "data",
@@ -1185,7 +1184,7 @@
     [SymbolFor("Deno.privateCustomInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(CustomEvent.prototype, this),
+        evaluate: this instanceof CustomEvent,
         keys: [
           ...EVENT_PROPS,
           "detail",
@@ -1215,7 +1214,7 @@
     [SymbolFor("Deno.privateCustomInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(ProgressEvent.prototype, this),
+        evaluate: this instanceof ProgressEvent,
         keys: [
           ...EVENT_PROPS,
           "lengthComputable",
@@ -1239,8 +1238,7 @@
 
       if (
         isSpecialErrorEventHandler &&
-        ObjectPrototypeIsPrototypeOf(ErrorEvent.prototype, evt) &&
-        evt.type === "error"
+        evt instanceof ErrorEvent && evt.type === "error"
       ) {
         const ret = FunctionPrototypeCall(
           wrappedHandler.handler,
diff --git a/ext/web/02_structured_clone.js b/ext/web/02_structured_clone.js
index 058390cfe..005b668af 100644
--- a/ext/web/02_structured_clone.js
+++ b/ext/web/02_structured_clone.js
@@ -13,12 +13,10 @@
   const { DOMException } = window.__bootstrap.domException;
   const {
     ArrayBuffer,
-    ArrayBufferPrototype,
     ArrayBufferIsView,
-    DataViewPrototype,
-    ObjectPrototypeIsPrototypeOf,
+    DataView,
     TypedArrayPrototypeSlice,
-    TypeErrorPrototype,
+    TypeError,
     WeakMap,
     WeakMapPrototypeSet,
   } = window.__bootstrap.primordials;
@@ -44,7 +42,7 @@
   function structuredClone(value) {
     // Performance optimization for buffers, otherwise
     // `serialize/deserialize` will allocate new buffer.
-    if (ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, value)) {
+    if (value instanceof ArrayBuffer) {
       const cloned = cloneArrayBuffer(
         value,
         0,
@@ -61,7 +59,7 @@
       // only DataView has a length in bytes and TypedArrays use a length in
       // terms of elements, so we adjust for that.
       let length;
-      if (ObjectPrototypeIsPrototypeOf(DataViewPrototype, view)) {
+      if (value instanceof DataView) {
         length = value.byteLength;
       } else {
         length = value.length;
@@ -76,7 +74,7 @@
     try {
       return core.deserialize(core.serialize(value));
     } catch (e) {
-      if (ObjectPrototypeIsPrototypeOf(TypeErrorPrototype, e)) {
+      if (e instanceof TypeError) {
         throw new DOMException("Uncloneable value", "DataCloneError");
       }
       throw e;
diff --git a/ext/web/03_abort_signal.js b/ext/web/03_abort_signal.js
index 8b089d031..cd9b11d4b 100644
--- a/ext/web/03_abort_signal.js
+++ b/ext/web/03_abort_signal.js
@@ -77,17 +77,17 @@
     }
 
     get aborted() {
-      webidl.assertBranded(this, AbortSignalPrototype);
+      webidl.assertBranded(this, AbortSignal);
       return this[abortReason] !== undefined;
     }
 
     get reason() {
-      webidl.assertBranded(this, AbortSignalPrototype);
+      webidl.assertBranded(this, AbortSignal);
       return this[abortReason];
     }
 
     throwIfAborted() {
-      webidl.assertBranded(this, AbortSignalPrototype);
+      webidl.assertBranded(this, AbortSignal);
       if (this[abortReason] !== undefined) {
         throw this[abortReason];
       }
@@ -96,7 +96,6 @@
   defineEventHandler(AbortSignal.prototype, "abort");
 
   webidl.configurePrototype(AbortSignal);
-  const AbortSignalPrototype = AbortSignal.prototype;
 
   class AbortController {
     [signal] = new AbortSignal(illegalConstructorKey);
@@ -106,22 +105,21 @@
     }
 
     get signal() {
-      webidl.assertBranded(this, AbortControllerPrototype);
+      webidl.assertBranded(this, AbortController);
       return this[signal];
     }
 
     abort(reason) {
-      webidl.assertBranded(this, AbortControllerPrototype);
+      webidl.assertBranded(this, AbortController);
       this[signal][signalAbort](reason);
     }
   }
 
   webidl.configurePrototype(AbortController);
-  const AbortControllerPrototype = AbortController.prototype;
 
   webidl.converters["AbortSignal"] = webidl.createInterfaceConverter(
     "AbortSignal",
-    AbortSignal.prototype,
+    AbortSignal,
   );
 
   function newSignal() {
@@ -144,7 +142,6 @@
   window.AbortSignal = AbortSignal;
   window.AbortController = AbortController;
   window.__bootstrap.abortSignal = {
-    AbortSignalPrototype,
     add,
     signalAbort,
     remove,
diff --git a/ext/web/06_streams.js b/ext/web/06_streams.js
index 777ad152b..d32a72c6e 100644
--- a/ext/web/06_streams.js
+++ b/ext/web/06_streams.js
@@ -9,22 +9,21 @@
 
 ((window) => {
   const webidl = window.__bootstrap.webidl;
-  const { add, remove, signalAbort, newSignal, AbortSignalPrototype } =
+  const { add, remove, signalAbort, newSignal } =
     window.__bootstrap.abortSignal;
   const {
     ArrayBuffer,
-    ArrayBufferPrototype,
     ArrayBufferIsView,
     ArrayPrototypeMap,
     ArrayPrototypePush,
     ArrayPrototypeShift,
-    BigInt64ArrayPrototype,
-    BigUint64ArrayPrototype,
+    BigInt64Array,
+    BigUint64Array,
     DataView,
     Error,
-    Int8ArrayPrototype,
-    Int16ArrayPrototype,
-    Int32ArrayPrototype,
+    Int8Array,
+    Int16Array,
+    Int32Array,
     NumberIsInteger,
     NumberIsNaN,
     MathMin,
@@ -32,7 +31,6 @@
     ObjectDefineProperties,
     ObjectDefineProperty,
     ObjectGetPrototypeOf,
-    ObjectPrototypeIsPrototypeOf,
     ObjectSetPrototypeOf,
     Promise,
     PromiseAll,
@@ -48,10 +46,9 @@
     SymbolFor,
     TypeError,
     Uint8Array,
-    Uint8ArrayPrototype,
-    Uint16ArrayPrototype,
-    Uint32ArrayPrototype,
-    Uint8ClampedArrayPrototype,
+    Uint16Array,
+    Uint32Array,
+    Uint8ClampedArray,
     WeakMap,
     WeakMapPrototypeGet,
     WeakMapPrototypeHas,
@@ -137,7 +134,7 @@
 
   /** @param {any} e */
   function rethrowAssertionErrorRejection(e) {
-    if (e && ObjectPrototypeIsPrototypeOf(AssertionError.prototype, e)) {
+    if (e && e instanceof AssertionError) {
       queueMicrotask(() => {
         console.error(`Internal Error: ${e.stack}`);
       });
@@ -217,10 +214,7 @@
    */
   function canTransferArrayBuffer(O) {
     assert(typeof O === "object");
-    assert(
-      ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, O) ||
-        ObjectPrototypeIsPrototypeOf(SharedArrayBuffer.prototype, O),
-    );
+    assert(O instanceof ArrayBuffer || O instanceof SharedArrayBuffer);
     if (isDetachedBuffer(O)) {
       return false;
     }
@@ -1370,15 +1364,15 @@
     let ctor = DataView;
 
     if (
-      ObjectPrototypeIsPrototypeOf(Int8ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(Uint8ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(Uint8ClampedArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(Int16ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(Uint16ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(Int32ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(Uint32ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(BigInt64ArrayPrototype, view) ||
-      ObjectPrototypeIsPrototypeOf(BigUint64ArrayPrototype, view)
+      view instanceof Int8Array ||
+      view instanceof Uint8Array ||
+      view instanceof Uint8ClampedArray ||
+      view instanceof Int16Array ||
+      view instanceof Uint16Array ||
+      view instanceof Int32Array ||
+      view instanceof Uint32Array ||
+      view instanceof BigInt64Array ||
+      view instanceof BigUint64Array
     ) {
       elementSize = view.constructor.BYTES_PER_ELEMENT;
       ctor = view.constructor;
@@ -1989,10 +1983,7 @@
       typeof preventClose === "boolean" && typeof preventAbort === "boolean" &&
         typeof preventCancel === "boolean",
     );
-    assert(
-      signal === undefined ||
-        ObjectPrototypeIsPrototypeOf(AbortSignalPrototype, signal),
-    );
+    assert(signal === undefined || signal instanceof AbortSignal);
     assert(!isReadableStreamLocked(source));
     assert(!isWritableStreamLocked(dest));
     // We use acquireReadableStreamDefaultReader even in case of ReadableByteStreamController
@@ -2336,12 +2327,7 @@
   function readableStreamTee(stream, cloneForBranch2) {
     assert(isReadableStream(stream));
     assert(typeof cloneForBranch2 === "boolean");
-    if (
-      ObjectPrototypeIsPrototypeOf(
-        ReadableByteStreamControllerPrototype,
-        stream[_controller],
-      )
-    ) {
+    if (stream[_controller] instanceof ReadableByteStreamController) {
       return readableByteStreamTee(stream);
     } else {
       return readableStreamDefaultTee(stream, cloneForBranch2);
@@ -2505,12 +2491,7 @@
    */
   function readableByteStreamTee(stream) {
     assert(isReadableStream(stream));
-    assert(
-      ObjectPrototypeIsPrototypeOf(
-        ReadableByteStreamControllerPrototype,
-        stream[_controller],
-      ),
-    );
+    assert(stream[_controller] instanceof ReadableByteStreamController);
     let reader = acquireReadableStreamDefaultReader(stream);
     let reading = false;
     let readAgainForBranch1 = false;
@@ -3018,12 +2999,7 @@
     if (isReadableStreamLocked(stream)) {
       throw new TypeError("ReadableStream is locked.");
     }
-    if (
-      !(ObjectPrototypeIsPrototypeOf(
-        ReadableByteStreamControllerPrototype,
-        stream[_controller],
-      ))
-    ) {
+    if (!(stream[_controller] instanceof ReadableByteStreamController)) {
       throw new TypeError("Cannot use a BYOB reader with a non-byte stream");
     }
     readableStreamReaderGenericInitialize(reader, stream);
@@ -3056,7 +3032,7 @@
     transformAlgorithm,
     flushAlgorithm,
   ) {
-    assert(ObjectPrototypeIsPrototypeOf(TransformStreamPrototype, stream));
+    assert(stream instanceof TransformStream);
     assert(stream[_controller] === undefined);
     controller[_stream] = stream;
     stream[_controller] = controller;
@@ -4198,13 +4174,13 @@
 
     /** @returns {number} */
     get highWaterMark() {
-      webidl.assertBranded(this, ByteLengthQueuingStrategyPrototype);
+      webidl.assertBranded(this, ByteLengthQueuingStrategy);
       return this[_highWaterMark];
     }
 
     /** @returns {(chunk: ArrayBufferView) => number} */
     get size() {
-      webidl.assertBranded(this, ByteLengthQueuingStrategyPrototype);
+      webidl.assertBranded(this, ByteLengthQueuingStrategy);
       initializeByteLengthSizeFunction(this[_globalObject]);
       return WeakMapPrototypeGet(byteSizeFunctionWeakMap, this[_globalObject]);
     }
@@ -4212,10 +4188,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          ByteLengthQueuingStrategyPrototype,
-          this,
-        ),
+        evaluate: this instanceof ByteLengthQueuingStrategy,
         keys: [
           "highWaterMark",
           "size",
@@ -4225,8 +4198,6 @@
   }
 
   webidl.configurePrototype(ByteLengthQueuingStrategy);
-  const ByteLengthQueuingStrategyPrototype =
-    ByteLengthQueuingStrategy.prototype;
 
   /** @type {WeakMap<typeof globalThis, (chunk: ArrayBufferView) => number>} */
   const byteSizeFunctionWeakMap = new WeakMap();
@@ -4255,13 +4226,13 @@
 
     /** @returns {number} */
     get highWaterMark() {
-      webidl.assertBranded(this, CountQueuingStrategyPrototype);
+      webidl.assertBranded(this, CountQueuingStrategy);
       return this[_highWaterMark];
     }
 
     /** @returns {(chunk: any) => 1} */
     get size() {
-      webidl.assertBranded(this, CountQueuingStrategyPrototype);
+      webidl.assertBranded(this, CountQueuingStrategy);
       initializeCountSizeFunction(this[_globalObject]);
       return WeakMapPrototypeGet(countSizeFunctionWeakMap, this[_globalObject]);
     }
@@ -4269,10 +4240,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          CountQueuingStrategyPrototype,
-          this,
-        ),
+        evaluate: this instanceof CountQueuingStrategy,
         keys: [
           "highWaterMark",
           "size",
@@ -4282,7 +4250,6 @@
   }
 
   webidl.configurePrototype(CountQueuingStrategy);
-  const CountQueuingStrategyPrototype = CountQueuingStrategy.prototype;
 
   /** @type {WeakMap<typeof globalThis, () => 1>} */
   const countSizeFunctionWeakMap = new WeakMap();
@@ -4366,7 +4333,7 @@
 
     /** @returns {boolean} */
     get locked() {
-      webidl.assertBranded(this, ReadableStreamPrototype);
+      webidl.assertBranded(this, ReadableStream);
       return isReadableStreamLocked(this);
     }
 
@@ -4376,7 +4343,7 @@
      */
     cancel(reason = undefined) {
       try {
-        webidl.assertBranded(this, ReadableStreamPrototype);
+        webidl.assertBranded(this, ReadableStream);
         if (reason !== undefined) {
           reason = webidl.converters.any(reason);
         }
@@ -4396,7 +4363,7 @@
      * @returns {ReadableStreamDefaultReader<R> | ReadableStreamBYOBReader}
      */
     getReader(options = {}) {
-      webidl.assertBranded(this, ReadableStreamPrototype);
+      webidl.assertBranded(this, ReadableStream);
       const prefix = "Failed to execute 'getReader' on 'ReadableStream'";
       options = webidl.converters.ReadableStreamGetReaderOptions(options, {
         prefix,
@@ -4417,7 +4384,7 @@
      * @returns {ReadableStream<T>}
      */
     pipeThrough(transform, options = {}) {
-      webidl.assertBranded(this, ReadableStreamPrototype);
+      webidl.assertBranded(this, ReadableStream);
       const prefix = "Failed to execute 'pipeThrough' on 'ReadableStream'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
       transform = webidl.converters.ReadableWritablePair(transform, {
@@ -4455,7 +4422,7 @@
      */
     pipeTo(destination, options = {}) {
       try {
-        webidl.assertBranded(this, ReadableStreamPrototype);
+        webidl.assertBranded(this, ReadableStream);
         const prefix = "Failed to execute 'pipeTo' on 'ReadableStream'";
         webidl.requiredArguments(arguments.length, 1, { prefix });
         destination = webidl.converters.WritableStream(destination, {
@@ -4492,7 +4459,7 @@
 
     /** @returns {[ReadableStream<R>, ReadableStream<R>]} */
     tee() {
-      webidl.assertBranded(this, ReadableStreamPrototype);
+      webidl.assertBranded(this, ReadableStream);
       return readableStreamTee(this, false);
     }
 
@@ -4502,7 +4469,7 @@
      * @returns {AsyncIterableIterator<R>}
      */
     values(options = {}) {
-      webidl.assertBranded(this, ReadableStreamPrototype);
+      webidl.assertBranded(this, ReadableStream);
       const prefix = "Failed to execute 'values' on 'ReadableStream'";
       options = webidl.converters.ReadableStreamIteratorOptions(options, {
         prefix,
@@ -4531,7 +4498,6 @@
   });
 
   webidl.configurePrototype(ReadableStream);
-  const ReadableStreamPrototype = ReadableStream.prototype;
 
   function errorReadableStream(stream, e) {
     readableStreamDefaultControllerError(stream[_controller], e);
@@ -4561,7 +4527,7 @@
     /** @returns {Promise<ReadableStreamReadResult<R>>} */
     read() {
       try {
-        webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
+        webidl.assertBranded(this, ReadableStreamDefaultReader);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -4590,7 +4556,7 @@
 
     /** @returns {void} */
     releaseLock() {
-      webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
+      webidl.assertBranded(this, ReadableStreamDefaultReader);
       if (this[_stream] === undefined) {
         return;
       }
@@ -4599,7 +4565,7 @@
 
     get closed() {
       try {
-        webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
+        webidl.assertBranded(this, ReadableStreamDefaultReader);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -4612,7 +4578,7 @@
      */
     cancel(reason = undefined) {
       try {
-        webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
+        webidl.assertBranded(this, ReadableStreamDefaultReader);
         if (reason !== undefined) {
           reason = webidl.converters.any(reason);
         }
@@ -4634,8 +4600,6 @@
   }
 
   webidl.configurePrototype(ReadableStreamDefaultReader);
-  const ReadableStreamDefaultReaderPrototype =
-    ReadableStreamDefaultReader.prototype;
 
   /** @template R */
   class ReadableStreamBYOBReader {
@@ -4664,7 +4628,7 @@
      */
     read(view) {
       try {
-        webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
+        webidl.assertBranded(this, ReadableStreamBYOBReader);
         const prefix = "Failed to execute 'read' on 'ReadableStreamBYOBReader'";
         view = webidl.converters.ArrayBufferView(view, {
           prefix,
@@ -4714,7 +4678,7 @@
 
     /** @returns {void} */
     releaseLock() {
-      webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
+      webidl.assertBranded(this, ReadableStreamBYOBReader);
       if (this[_stream] === undefined) {
         return;
       }
@@ -4723,7 +4687,7 @@
 
     get closed() {
       try {
-        webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
+        webidl.assertBranded(this, ReadableStreamBYOBReader);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -4736,7 +4700,7 @@
      */
     cancel(reason = undefined) {
       try {
-        webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
+        webidl.assertBranded(this, ReadableStreamBYOBReader);
         if (reason !== undefined) {
           reason = webidl.converters.any(reason);
         }
@@ -4758,7 +4722,6 @@
   }
 
   webidl.configurePrototype(ReadableStreamBYOBReader);
-  const ReadableStreamBYOBReaderPrototype = ReadableStreamBYOBReader.prototype;
 
   class ReadableStreamBYOBRequest {
     /** @type {ReadableByteStreamController} */
@@ -4768,7 +4731,7 @@
 
     /** @returns {ArrayBufferView | null} */
     get view() {
-      webidl.assertBranded(this, ReadableStreamBYOBRequestPrototype);
+      webidl.assertBranded(this, ReadableStreamBYOBRequest);
       return this[_view];
     }
 
@@ -4777,7 +4740,7 @@
     }
 
     respond(bytesWritten) {
-      webidl.assertBranded(this, ReadableStreamBYOBRequestPrototype);
+      webidl.assertBranded(this, ReadableStreamBYOBRequest);
       const prefix =
         "Failed to execute 'respond' on 'ReadableStreamBYOBRequest'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
@@ -4801,7 +4764,7 @@
     }
 
     respondWithNewView(view) {
-      webidl.assertBranded(this, ReadableStreamBYOBRequestPrototype);
+      webidl.assertBranded(this, ReadableStreamBYOBRequest);
       const prefix =
         "Failed to execute 'respondWithNewView' on 'ReadableStreamBYOBRequest'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
@@ -4823,8 +4786,6 @@
   }
 
   webidl.configurePrototype(ReadableStreamBYOBRequest);
-  const ReadableStreamBYOBRequestPrototype =
-    ReadableStreamBYOBRequest.prototype;
 
   class ReadableByteStreamController {
     /** @type {number | undefined} */
@@ -4860,19 +4821,19 @@
 
     /** @returns {ReadableStreamBYOBRequest | null} */
     get byobRequest() {
-      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
+      webidl.assertBranded(this, ReadableByteStreamController);
       return readableByteStreamControllerGetBYOBRequest(this);
     }
 
     /** @returns {number | null} */
     get desiredSize() {
-      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
+      webidl.assertBranded(this, ReadableByteStreamController);
       return readableByteStreamControllerGetDesiredSize(this);
     }
 
     /** @returns {void} */
     close() {
-      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
+      webidl.assertBranded(this, ReadableByteStreamController);
       if (this[_closeRequested] === true) {
         throw new TypeError("Closed already requested.");
       }
@@ -4889,7 +4850,7 @@
      * @returns {void}
      */
     enqueue(chunk) {
-      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
+      webidl.assertBranded(this, ReadableByteStreamController);
       const prefix =
         "Failed to execute 'enqueue' on 'ReadableByteStreamController'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
@@ -4929,7 +4890,7 @@
      * @returns {void}
      */
     error(e = undefined) {
-      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
+      webidl.assertBranded(this, ReadableByteStreamController);
       if (e !== undefined) {
         e = webidl.converters.any(e);
       }
@@ -4939,10 +4900,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          ReadableByteStreamControllerPrototype,
-          this,
-        ),
+        evaluate: this instanceof ReadableByteStreamController,
         keys: ["desiredSize"],
       }));
     }
@@ -5009,8 +4967,6 @@
   }
 
   webidl.configurePrototype(ReadableByteStreamController);
-  const ReadableByteStreamControllerPrototype =
-    ReadableByteStreamController.prototype;
 
   /** @template R */
   class ReadableStreamDefaultController {
@@ -5043,13 +4999,13 @@
 
     /** @returns {number | null} */
     get desiredSize() {
-      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, ReadableStreamDefaultController);
       return readableStreamDefaultControllerGetDesiredSize(this);
     }
 
     /** @returns {void} */
     close() {
-      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, ReadableStreamDefaultController);
       if (readableStreamDefaultControllerCanCloseOrEnqueue(this) === false) {
         throw new TypeError("The stream controller cannot close or enqueue.");
       }
@@ -5061,7 +5017,7 @@
      * @returns {void}
      */
     enqueue(chunk = undefined) {
-      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, ReadableStreamDefaultController);
       if (chunk !== undefined) {
         chunk = webidl.converters.any(chunk);
       }
@@ -5076,7 +5032,7 @@
      * @returns {void}
      */
     error(e = undefined) {
-      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, ReadableStreamDefaultController);
       if (e !== undefined) {
         e = webidl.converters.any(e);
       }
@@ -5086,10 +5042,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          ReadableStreamDefaultController.prototype,
-          this,
-        ),
+        evaluate: this instanceof ReadableStreamDefaultController,
         keys: ["desiredSize"],
       }));
     }
@@ -5132,8 +5085,6 @@
   }
 
   webidl.configurePrototype(ReadableStreamDefaultController);
-  const ReadableStreamDefaultControllerPrototype =
-    ReadableStreamDefaultController.prototype;
 
   /**
    * @template I
@@ -5235,13 +5186,13 @@
 
     /** @returns {ReadableStream<O>} */
     get readable() {
-      webidl.assertBranded(this, TransformStreamPrototype);
+      webidl.assertBranded(this, TransformStream);
       return this[_readable];
     }
 
     /** @returns {WritableStream<I>} */
     get writable() {
-      webidl.assertBranded(this, TransformStreamPrototype);
+      webidl.assertBranded(this, TransformStream);
       return this[_writable];
     }
 
@@ -5253,7 +5204,6 @@
   }
 
   webidl.configurePrototype(TransformStream);
-  const TransformStreamPrototype = TransformStream.prototype;
 
   /** @template O */
   class TransformStreamDefaultController {
@@ -5270,7 +5220,7 @@
 
     /** @returns {number | null} */
     get desiredSize() {
-      webidl.assertBranded(this, TransformStreamDefaultController.prototype);
+      webidl.assertBranded(this, TransformStreamDefaultController);
       const readableController = this[_stream][_readable][_controller];
       return readableStreamDefaultControllerGetDesiredSize(
         /** @type {ReadableStreamDefaultController<O>} */ readableController,
@@ -5282,7 +5232,7 @@
      * @returns {void}
      */
     enqueue(chunk = undefined) {
-      webidl.assertBranded(this, TransformStreamDefaultController.prototype);
+      webidl.assertBranded(this, TransformStreamDefaultController);
       if (chunk !== undefined) {
         chunk = webidl.converters.any(chunk);
       }
@@ -5294,7 +5244,7 @@
      * @returns {void}
      */
     error(reason = undefined) {
-      webidl.assertBranded(this, TransformStreamDefaultController.prototype);
+      webidl.assertBranded(this, TransformStreamDefaultController);
       if (reason !== undefined) {
         reason = webidl.converters.any(reason);
       }
@@ -5303,25 +5253,20 @@
 
     /** @returns {void} */
     terminate() {
-      webidl.assertBranded(this, TransformStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, TransformStreamDefaultController);
       transformStreamDefaultControllerTerminate(this);
     }
 
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          TransformStreamDefaultController.prototype,
-          this,
-        ),
+        evaluate: this instanceof TransformStreamDefaultController,
         keys: ["desiredSize"],
       }));
     }
   }
 
   webidl.configurePrototype(TransformStreamDefaultController);
-  const TransformStreamDefaultControllerPrototype =
-    TransformStreamDefaultController.prototype;
 
   /** @template W */
   class WritableStream {
@@ -5391,7 +5336,7 @@
 
     /** @returns {boolean} */
     get locked() {
-      webidl.assertBranded(this, WritableStreamPrototype);
+      webidl.assertBranded(this, WritableStream);
       return isWritableStreamLocked(this);
     }
 
@@ -5401,7 +5346,7 @@
      */
     abort(reason = undefined) {
       try {
-        webidl.assertBranded(this, WritableStreamPrototype);
+        webidl.assertBranded(this, WritableStream);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -5421,7 +5366,7 @@
     /** @returns {Promise<void>} */
     close() {
       try {
-        webidl.assertBranded(this, WritableStreamPrototype);
+        webidl.assertBranded(this, WritableStream);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -5442,7 +5387,7 @@
 
     /** @returns {WritableStreamDefaultWriter<W>} */
     getWriter() {
-      webidl.assertBranded(this, WritableStreamPrototype);
+      webidl.assertBranded(this, WritableStream);
       return acquireWritableStreamDefaultWriter(this);
     }
 
@@ -5452,7 +5397,6 @@
   }
 
   webidl.configurePrototype(WritableStream);
-  const WritableStreamPrototype = WritableStream.prototype;
 
   /** @template W */
   class WritableStreamDefaultWriter {
@@ -5482,7 +5426,7 @@
     /** @returns {Promise<void>} */
     get closed() {
       try {
-        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+        webidl.assertBranded(this, WritableStreamDefaultWriter);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -5491,7 +5435,7 @@
 
     /** @returns {number} */
     get desiredSize() {
-      webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+      webidl.assertBranded(this, WritableStreamDefaultWriter);
       if (this[_stream] === undefined) {
         throw new TypeError(
           "A writable stream is not associated with the writer.",
@@ -5503,7 +5447,7 @@
     /** @returns {Promise<void>} */
     get ready() {
       try {
-        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+        webidl.assertBranded(this, WritableStreamDefaultWriter);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -5516,7 +5460,7 @@
      */
     abort(reason = undefined) {
       try {
-        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+        webidl.assertBranded(this, WritableStreamDefaultWriter);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -5534,7 +5478,7 @@
     /** @returns {Promise<void>} */
     close() {
       try {
-        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+        webidl.assertBranded(this, WritableStreamDefaultWriter);
       } catch (err) {
         return PromiseReject(err);
       }
@@ -5554,7 +5498,7 @@
 
     /** @returns {void} */
     releaseLock() {
-      webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+      webidl.assertBranded(this, WritableStreamDefaultWriter);
       const stream = this[_stream];
       if (stream === undefined) {
         return;
@@ -5569,7 +5513,7 @@
      */
     write(chunk = undefined) {
       try {
-        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
+        webidl.assertBranded(this, WritableStreamDefaultWriter);
         if (chunk !== undefined) {
           chunk = webidl.converters.any(chunk);
         }
@@ -5587,10 +5531,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          WritableStreamDefaultWriter.prototype,
-          this,
-        ),
+        evaluate: this instanceof WritableStreamDefaultWriter,
         keys: [
           "closed",
           "desiredSize",
@@ -5601,8 +5542,6 @@
   }
 
   webidl.configurePrototype(WritableStreamDefaultWriter);
-  const WritableStreamDefaultWriterPrototype =
-    WritableStreamDefaultWriter.prototype;
 
   /** @template W */
   class WritableStreamDefaultController {
@@ -5628,7 +5567,7 @@
     [_signal];
 
     get signal() {
-      webidl.assertBranded(this, WritableStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, WritableStreamDefaultController);
       return this[_signal];
     }
 
@@ -5641,7 +5580,7 @@
      * @returns {void}
      */
     error(e = undefined) {
-      webidl.assertBranded(this, WritableStreamDefaultControllerPrototype);
+      webidl.assertBranded(this, WritableStreamDefaultController);
       if (e !== undefined) {
         e = webidl.converters.any(e);
       }
@@ -5655,10 +5594,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(
-          WritableStreamDefaultController.prototype,
-          this,
-        ),
+        evaluate: this instanceof WritableStreamDefaultController,
         keys: [],
       }));
     }
@@ -5679,8 +5615,6 @@
   }
 
   webidl.configurePrototype(WritableStreamDefaultController);
-  const WritableStreamDefaultControllerPrototype =
-    WritableStreamDefaultController.prototype;
 
   /**
    * @param {ReadableStream} stream
@@ -5690,9 +5624,9 @@
   }
 
   webidl.converters.ReadableStream = webidl
-    .createInterfaceConverter("ReadableStream", ReadableStream.prototype);
+    .createInterfaceConverter("ReadableStream", ReadableStream);
   webidl.converters.WritableStream = webidl
-    .createInterfaceConverter("WritableStream", WritableStream.prototype);
+    .createInterfaceConverter("WritableStream", WritableStream);
 
   webidl.converters.ReadableStreamType = webidl.createEnumConverter(
     "ReadableStreamType",
@@ -5853,7 +5787,6 @@
     ByteLengthQueuingStrategy,
     CountQueuingStrategy,
     ReadableStream,
-    ReadableStreamPrototype,
     ReadableStreamDefaultReader,
     TransformStream,
     WritableStream,
diff --git a/ext/web/08_text_encoding.js b/ext/web/08_text_encoding.js
index 4f26089b1..cf7b7e12f 100644
--- a/ext/web/08_text_encoding.js
+++ b/ext/web/08_text_encoding.js
@@ -16,7 +16,6 @@
   const webidl = window.__bootstrap.webidl;
   const {
     ArrayBufferIsView,
-    ObjectPrototypeIsPrototypeOf,
     PromiseReject,
     PromiseResolve,
     StringPrototypeCharCodeAt,
@@ -60,19 +59,19 @@
 
     /** @returns {string} */
     get encoding() {
-      webidl.assertBranded(this, TextDecoderPrototype);
+      webidl.assertBranded(this, TextDecoder);
       return this.#encoding;
     }
 
     /** @returns {boolean} */
     get fatal() {
-      webidl.assertBranded(this, TextDecoderPrototype);
+      webidl.assertBranded(this, TextDecoder);
       return this.#fatal;
     }
 
     /** @returns {boolean} */
     get ignoreBOM() {
-      webidl.assertBranded(this, TextDecoderPrototype);
+      webidl.assertBranded(this, TextDecoder);
       return this.#ignoreBOM;
     }
 
@@ -81,7 +80,7 @@
      * @param {TextDecodeOptions} options
      */
     decode(input = new Uint8Array(), options = {}) {
-      webidl.assertBranded(this, TextDecoderPrototype);
+      webidl.assertBranded(this, TextDecoder);
       const prefix = "Failed to execute 'decode' on 'TextDecoder'";
       if (input !== undefined) {
         input = webidl.converters.BufferSource(input, {
@@ -120,12 +119,7 @@
           // If the buffer is detached, just create a new empty Uint8Array.
           input = new Uint8Array();
         }
-        if (
-          ObjectPrototypeIsPrototypeOf(
-            SharedArrayBuffer.prototype,
-            input.buffer,
-          )
-        ) {
+        if (input.buffer instanceof SharedArrayBuffer) {
           // We clone the data into a non-shared ArrayBuffer so we can pass it
           // to Rust.
           // `input` is now a Uint8Array, and calling the TypedArray constructor
@@ -146,7 +140,6 @@
   }
 
   webidl.configurePrototype(TextDecoder);
-  const TextDecoderPrototype = TextDecoder.prototype;
 
   class TextEncoder {
     constructor() {
@@ -155,7 +148,7 @@
 
     /** @returns {string} */
     get encoding() {
-      webidl.assertBranded(this, TextEncoderPrototype);
+      webidl.assertBranded(this, TextEncoder);
       return "utf-8";
     }
 
@@ -164,7 +157,7 @@
      * @returns {Uint8Array}
      */
     encode(input = "") {
-      webidl.assertBranded(this, TextEncoderPrototype);
+      webidl.assertBranded(this, TextEncoder);
       const prefix = "Failed to execute 'encode' on 'TextEncoder'";
       // The WebIDL type of `input` is `USVString`, but `core.encode` already
       // converts lone surrogates to the replacement character.
@@ -181,7 +174,7 @@
      * @returns {TextEncoderEncodeIntoResult}
      */
     encodeInto(source, destination) {
-      webidl.assertBranded(this, TextEncoderPrototype);
+      webidl.assertBranded(this, TextEncoder);
       const prefix = "Failed to execute 'encodeInto' on 'TextEncoder'";
       // The WebIDL type of `source` is `USVString`, but the ops bindings
       // already convert lone surrogates to the replacement character.
@@ -199,7 +192,6 @@
   }
 
   webidl.configurePrototype(TextEncoder);
-  const TextEncoderPrototype = TextEncoder.prototype;
 
   class TextDecoderStream {
     /** @type {TextDecoder} */
@@ -256,37 +248,36 @@
 
     /** @returns {string} */
     get encoding() {
-      webidl.assertBranded(this, TextDecoderStreamPrototype);
+      webidl.assertBranded(this, TextDecoderStream);
       return this.#decoder.encoding;
     }
 
     /** @returns {boolean} */
     get fatal() {
-      webidl.assertBranded(this, TextDecoderStreamPrototype);
+      webidl.assertBranded(this, TextDecoderStream);
       return this.#decoder.fatal;
     }
 
     /** @returns {boolean} */
     get ignoreBOM() {
-      webidl.assertBranded(this, TextDecoderStreamPrototype);
+      webidl.assertBranded(this, TextDecoderStream);
       return this.#decoder.ignoreBOM;
     }
 
     /** @returns {ReadableStream<string>} */
     get readable() {
-      webidl.assertBranded(this, TextDecoderStreamPrototype);
+      webidl.assertBranded(this, TextDecoderStream);
       return this.#transform.readable;
     }
 
     /** @returns {WritableStream<BufferSource>} */
     get writable() {
-      webidl.assertBranded(this, TextDecoderStreamPrototype);
+      webidl.assertBranded(this, TextDecoderStream);
       return this.#transform.writable;
     }
   }
 
   webidl.configurePrototype(TextDecoderStream);
-  const TextDecoderStreamPrototype = TextDecoderStream.prototype;
 
   class TextEncoderStream {
     /** @type {string | null} */
@@ -341,25 +332,24 @@
 
     /** @returns {string} */
     get encoding() {
-      webidl.assertBranded(this, TextEncoderStreamPrototype);
+      webidl.assertBranded(this, TextEncoderStream);
       return "utf-8";
     }
 
     /** @returns {ReadableStream<Uint8Array>} */
     get readable() {
-      webidl.assertBranded(this, TextEncoderStreamPrototype);
+      webidl.assertBranded(this, TextEncoderStream);
       return this.#transform.readable;
     }
 
     /** @returns {WritableStream<string>} */
     get writable() {
-      webidl.assertBranded(this, TextEncoderStreamPrototype);
+      webidl.assertBranded(this, TextEncoderStream);
       return this.#transform.writable;
     }
   }
 
   webidl.configurePrototype(TextEncoderStream);
-  const TextEncoderStreamPrototype = TextEncoderStream.prototype;
 
   webidl.converters.TextDecoderOptions = webidl.createDictionaryConverter(
     "TextDecoderOptions",
diff --git a/ext/web/09_file.js b/ext/web/09_file.js
index fbc00326e..289db22ec 100644
--- a/ext/web/09_file.js
+++ b/ext/web/09_file.js
@@ -15,7 +15,7 @@
   const core = window.Deno.core;
   const webidl = window.__bootstrap.webidl;
   const {
-    ArrayBufferPrototype,
+    ArrayBuffer,
     ArrayBufferPrototypeSlice,
     ArrayBufferIsView,
     ArrayPrototypePush,
@@ -23,7 +23,6 @@
     DatePrototypeGetTime,
     MathMax,
     MathMin,
-    ObjectPrototypeIsPrototypeOf,
     RegExpPrototypeTest,
     StringPrototypeCharAt,
     StringPrototypeToLowerCase,
@@ -110,7 +109,7 @@
     const processedParts = [];
     let size = 0;
     for (const element of parts) {
-      if (ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, element)) {
+      if (element instanceof ArrayBuffer) {
         const chunk = new Uint8Array(ArrayBufferPrototypeSlice(element, 0));
         ArrayPrototypePush(processedParts, BlobReference.fromUint8Array(chunk));
         size += element.byteLength;
@@ -122,7 +121,7 @@
         );
         size += element.byteLength;
         ArrayPrototypePush(processedParts, BlobReference.fromUint8Array(chunk));
-      } else if (ObjectPrototypeIsPrototypeOf(BlobPrototype, element)) {
+      } else if (element instanceof Blob) {
         ArrayPrototypePush(processedParts, element);
         size += element.size;
       } else if (typeof element === "string") {
@@ -158,7 +157,7 @@
    */
   function getParts(blob, bag = []) {
     for (const part of blob[_parts]) {
-      if (ObjectPrototypeIsPrototypeOf(BlobPrototype, part)) {
+      if (part instanceof Blob) {
         getParts(part, bag);
       } else {
         ArrayPrototypePush(bag, part._id);
@@ -205,13 +204,13 @@
 
     /** @returns {number} */
     get size() {
-      webidl.assertBranded(this, BlobPrototype);
+      webidl.assertBranded(this, Blob);
       return this[_size];
     }
 
     /** @returns {string} */
     get type() {
-      webidl.assertBranded(this, BlobPrototype);
+      webidl.assertBranded(this, Blob);
       return this[_type];
     }
 
@@ -222,7 +221,7 @@
      * @returns {Blob}
      */
     slice(start = undefined, end = undefined, contentType = undefined) {
-      webidl.assertBranded(this, BlobPrototype);
+      webidl.assertBranded(this, Blob);
       const prefix = "Failed to execute 'slice' on 'Blob'";
       if (start !== undefined) {
         start = webidl.converters["long long"](start, {
@@ -317,7 +316,7 @@
      * @returns {ReadableStream<Uint8Array>}
      */
     stream() {
-      webidl.assertBranded(this, BlobPrototype);
+      webidl.assertBranded(this, Blob);
       const partIterator = toIterator(this[_parts]);
       const stream = new ReadableStream({
         type: "bytes",
@@ -339,7 +338,7 @@
      * @returns {Promise<string>}
      */
     async text() {
-      webidl.assertBranded(this, BlobPrototype);
+      webidl.assertBranded(this, Blob);
       const buffer = await this.arrayBuffer();
       return core.decode(new Uint8Array(buffer));
     }
@@ -348,7 +347,7 @@
      * @returns {Promise<ArrayBuffer>}
      */
     async arrayBuffer() {
-      webidl.assertBranded(this, BlobPrototype);
+      webidl.assertBranded(this, Blob);
       const stream = this.stream();
       const bytes = new Uint8Array(this.size);
       let offset = 0;
@@ -362,7 +361,7 @@
     [SymbolFor("Deno.customInspect")](inspect) {
       return inspect(consoleInternal.createFilteredInspectProxy({
         object: this,
-        evaluate: ObjectPrototypeIsPrototypeOf(BlobPrototype, this),
+        evaluate: this instanceof Blob,
         keys: [
           "size",
           "type",
@@ -372,22 +371,15 @@
   }
 
   webidl.configurePrototype(Blob);
-  const BlobPrototype = Blob.prototype;
 
-  webidl.converters["Blob"] = webidl.createInterfaceConverter(
-    "Blob",
-    Blob.prototype,
-  );
+  webidl.converters["Blob"] = webidl.createInterfaceConverter("Blob", Blob);
   webidl.converters["BlobPart"] = (V, opts) => {
     // Union for ((ArrayBuffer or ArrayBufferView) or Blob or USVString)
     if (typeof V == "object") {
-      if (ObjectPrototypeIsPrototypeOf(BlobPrototype, V)) {
+      if (V instanceof Blob) {
         return webidl.converters["Blob"](V, opts);
       }
-      if (
-        ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, V) ||
-        ObjectPrototypeIsPrototypeOf(SharedArrayBuffer.prototype, V)
-      ) {
+      if (V instanceof ArrayBuffer || V instanceof SharedArrayBuffer) {
         return webidl.converters["ArrayBuffer"](V, opts);
       }
       if (ArrayBufferIsView(V)) {
@@ -466,19 +458,18 @@
 
     /** @returns {string} */
     get name() {
-      webidl.assertBranded(this, FilePrototype);
+      webidl.assertBranded(this, File);
       return this[_Name];
     }
 
     /** @returns {number} */
     get lastModified() {
-      webidl.assertBranded(this, FilePrototype);
+      webidl.assertBranded(this, File);
       return this[_LastModified];
     }
   }
 
   webidl.configurePrototype(File);
-  const FilePrototype = File.prototype;
 
   webidl.converters["FilePropertyBag"] = webidl.createDictionaryConverter(
     "FilePropertyBag",
@@ -602,8 +593,6 @@
     blobFromObjectUrl,
     getParts,
     Blob,
-    BlobPrototype,
     File,
-    FilePrototype,
   };
 })(this);
diff --git a/ext/web/10_filereader.js b/ext/web/10_filereader.js
index 039d3395d..294d96ebd 100644
--- a/ext/web/10_filereader.js
+++ b/ext/web/10_filereader.js
@@ -28,14 +28,12 @@
     MapPrototypeGet,
     MapPrototypeSet,
     ObjectDefineProperty,
-    ObjectPrototypeIsPrototypeOf,
     queueMicrotask,
     StringFromCodePoint,
     Symbol,
     TypedArrayPrototypeSet,
     TypeError,
     Uint8Array,
-    Uint8ArrayPrototype,
   } = window.__bootstrap.primordials;
 
   const state = Symbol("[[state]]");
@@ -118,10 +116,7 @@
 
             // 4. If chunkPromise is fulfilled with an object whose done property is false
             // and whose value property is a Uint8Array object, run these steps:
-            if (
-              !chunk.done &&
-              ObjectPrototypeIsPrototypeOf(Uint8ArrayPrototype, chunk.value)
-            ) {
+            if (!chunk.done && chunk.value instanceof Uint8Array) {
               ArrayPrototypePush(chunks, chunk.value);
 
               // TODO(bartlomieju): (only) If roughly 50ms have passed since last progress
@@ -265,7 +260,7 @@
     }
 
     #getEventHandlerFor(name) {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
 
       const maybeMap = this[handlerSymbol];
       if (!maybeMap) return null;
@@ -274,7 +269,7 @@
     }
 
     #setEventHandlerFor(name, value) {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
 
       if (!this[handlerSymbol]) {
         this[handlerSymbol] = new Map();
@@ -297,7 +292,7 @@
 
     /** @returns {number} */
     get readyState() {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       switch (this[state]) {
         case "empty":
           return FileReader.EMPTY;
@@ -311,17 +306,17 @@
     }
 
     get result() {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       return this[result];
     }
 
     get error() {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       return this[error];
     }
 
     abort() {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       // If context object's state is "empty" or if context object's state is "done" set context object's result to null and terminate this algorithm.
       if (
         this[state] === "empty" ||
@@ -354,7 +349,7 @@
 
     /** @param {Blob} blob */
     readAsArrayBuffer(blob) {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       const prefix = "Failed to execute 'readAsArrayBuffer' on 'FileReader'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
       this.#readOperation(blob, { kind: "ArrayBuffer" });
@@ -362,7 +357,7 @@
 
     /** @param {Blob} blob */
     readAsBinaryString(blob) {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       const prefix = "Failed to execute 'readAsBinaryString' on 'FileReader'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
       // alias for readAsArrayBuffer
@@ -371,7 +366,7 @@
 
     /** @param {Blob} blob */
     readAsDataURL(blob) {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       const prefix = "Failed to execute 'readAsDataURL' on 'FileReader'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
       // alias for readAsArrayBuffer
@@ -383,7 +378,7 @@
      * @param {string} [encoding]
      */
     readAsText(blob, encoding = undefined) {
-      webidl.assertBranded(this, FileReaderPrototype);
+      webidl.assertBranded(this, FileReader);
       const prefix = "Failed to execute 'readAsText' on 'FileReader'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
       if (encoding !== undefined) {
@@ -440,7 +435,6 @@
   }
 
   webidl.configurePrototype(FileReader);
-  const FileReaderPrototype = FileReader.prototype;
 
   ObjectDefineProperty(FileReader, "EMPTY", {
     writable: false,
diff --git a/ext/web/13_message_port.js b/ext/web/13_message_port.js
index 8242f85f3..ef332dd7a 100644
--- a/ext/web/13_message_port.js
+++ b/ext/web/13_message_port.js
@@ -10,21 +10,19 @@
 
 ((window) => {
   const core = window.Deno.core;
-  const { InterruptedPrototype } = core;
+  const { Interrupted } = core;
   const webidl = window.__bootstrap.webidl;
   const { setEventTargetData } = window.__bootstrap.eventTarget;
   const { defineEventHandler } = window.__bootstrap.event;
   const { DOMException } = window.__bootstrap.domException;
   const {
-    ArrayBufferPrototype,
+    ArrayBuffer,
     ArrayPrototypeFilter,
     ArrayPrototypeIncludes,
     ArrayPrototypePush,
-    ObjectPrototypeIsPrototypeOf,
     ObjectSetPrototypeOf,
     Symbol,
     SymbolFor,
-    SymbolIterator,
     TypeError,
     WeakSet,
     WeakSetPrototypeAdd,
@@ -47,12 +45,12 @@
     }
 
     get port1() {
-      webidl.assertBranded(this, MessageChannelPrototype);
+      webidl.assertBranded(this, MessageChannel);
       return this.#port1;
     }
 
     get port2() {
-      webidl.assertBranded(this, MessageChannelPrototype);
+      webidl.assertBranded(this, MessageChannel);
       return this.#port2;
     }
 
@@ -64,7 +62,6 @@
   }
 
   webidl.configurePrototype(MessageChannel);
-  const MessageChannelPrototype = MessageChannel.prototype;
 
   const _id = Symbol("id");
   const _enabled = Symbol("enabled");
@@ -75,7 +72,7 @@
    */
   function createMessagePort(id) {
     const port = core.createHostObject();
-    ObjectSetPrototypeOf(port, MessagePortPrototype);
+    ObjectSetPrototypeOf(port, MessagePort.prototype);
     port[webidl.brand] = webidl.brand;
     setEventTargetData(port);
     port[_id] = id;
@@ -98,7 +95,7 @@
      * @param {object[] | StructuredSerializeOptions} transferOrOptions
      */
     postMessage(message, transferOrOptions = {}) {
-      webidl.assertBranded(this, MessagePortPrototype);
+      webidl.assertBranded(this, MessagePort);
       const prefix = "Failed to execute 'postMessage' on 'MessagePort'";
       webidl.requiredArguments(arguments.length, 1, { prefix });
       message = webidl.converters.any(message);
@@ -106,7 +103,7 @@
       if (
         webidl.type(transferOrOptions) === "Object" &&
         transferOrOptions !== undefined &&
-        transferOrOptions[SymbolIterator] !== undefined
+        transferOrOptions[Symbol.iterator] !== undefined
       ) {
         const transfer = webidl.converters["sequence<object>"](
           transferOrOptions,
@@ -132,7 +129,7 @@
     }
 
     start() {
-      webidl.assertBranded(this, MessagePortPrototype);
+      webidl.assertBranded(this, MessagePort);
       if (this[_enabled]) return;
       (async () => {
         this[_enabled] = true;
@@ -145,7 +142,7 @@
               this[_id],
             );
           } catch (err) {
-            if (ObjectPrototypeIsPrototypeOf(InterruptedPrototype, err)) break;
+            if (err instanceof Interrupted) break;
             throw err;
           }
           if (data === null) break;
@@ -163,7 +160,7 @@
             data: message,
             ports: ArrayPrototypeFilter(
               transferables,
-              (t) => ObjectPrototypeIsPrototypeOf(MessagePortPrototype, t),
+              (t) => t instanceof MessagePort,
             ),
           });
           this.dispatchEvent(event);
@@ -173,7 +170,7 @@
     }
 
     close() {
-      webidl.assertBranded(this, MessagePortPrototype);
+      webidl.assertBranded(this, MessagePort);
       if (this[_id] !== null) {
         core.close(this[_id]);
         this[_id] = null;
@@ -187,7 +184,6 @@
   defineEventHandler(MessagePort.prototype, "messageerror");
 
   webidl.configurePrototype(MessagePort);
-  const MessagePortPrototype = MessagePort.prototype;
 
   /**
    * @returns {[number, number]}
@@ -249,7 +245,7 @@
   function serializeJsMessageData(data, transferables) {
     const transferedArrayBuffers = ArrayPrototypeFilter(
       transferables,
-      (a) => ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, a),
+      (a) => a instanceof ArrayBuffer,
     );
 
     for (const arrayBuffer of transferedArrayBuffers) {
@@ -270,7 +266,7 @@
       serializedData = core.serialize(data, {
         hostObjects: ArrayPrototypeFilter(
           transferables,
-          (a) => ObjectPrototypeIsPrototypeOf(MessagePortPrototype, a),
+          (a) => a instanceof MessagePort,
         ),
         transferedArrayBuffers,
       });
@@ -283,8 +279,8 @@
 
     let arrayBufferI = 0;
     for (const transferable of transferables) {
-      if (ObjectPrototypeIsPrototypeOf(MessagePortPrototype, transferable)) {
-        webidl.assertBranded(transferable, MessagePortPrototype);
+      if (transferable instanceof MessagePort) {
+        webidl.assertBranded(transferable, MessagePort);
         const id = transferable[_id];
         if (id === null) {
           throw new DOMException(
@@ -297,9 +293,7 @@
           kind: "messagePort",
           data: id,
         });
-      } else if (
-        ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, transferable)
-      ) {
+      } else if (transferable instanceof ArrayBuffer) {
         ArrayPrototypePush(serializedTransferables, {
           kind: "arrayBuffer",
           data: transferedArrayBuffers[arrayBufferI],
@@ -345,7 +339,6 @@
   window.__bootstrap.messagePort = {
     MessageChannel,
     MessagePort,
-    MessagePortPrototype,
     deserializeJsMessageData,
     serializeJsMessageData,
     structuredClone,
diff --git a/ext/web/14_compression.js b/ext/web/14_compression.js
index 081495894..1a0f77e66 100644
--- a/ext/web/14_compression.js
+++ b/ext/web/14_compression.js
@@ -53,18 +53,17 @@
     }
 
     get readable() {
-      webidl.assertBranded(this, CompressionStreamPrototype);
+      webidl.assertBranded(this, CompressionStream);
       return this.#transform.readable;
     }
 
     get writable() {
-      webidl.assertBranded(this, CompressionStreamPrototype);
+      webidl.assertBranded(this, CompressionStream);
       return this.#transform.writable;
     }
   }
 
   webidl.configurePrototype(CompressionStream);
-  const CompressionStreamPrototype = CompressionStream.prototype;
 
   class DecompressionStream {
     #transform;
@@ -99,12 +98,12 @@
     }
 
     get readable() {
-      webidl.assertBranded(this, DecompressionStreamPrototype);
+      webidl.assertBranded(this, DecompressionStream);
       return this.#transform.readable;
     }
 
     get writable() {
-      webidl.assertBranded(this, DecompressionStreamPrototype);
+      webidl.assertBranded(this, DecompressionStream);
       return this.#transform.writable;
     }
   }
@@ -116,7 +115,6 @@
   }
 
   webidl.configurePrototype(DecompressionStream);
-  const DecompressionStreamPrototype = DecompressionStream.prototype;
 
   window.__bootstrap.compression = {
     CompressionStream,