LibWeb: Add the WritableStream interface

1 files changed, 13 insertions, 0 deletions

diff --git a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
index 0ed20ddebb..367883635a 100644
--- a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
+++ b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
@@ -13,7 +13,9 @@
 #include <LibWeb/Streams/ReadableStreamDefaultController.h>
 #include <LibWeb/Streams/ReadableStreamDefaultReader.h>
 #include <LibWeb/Streams/ReadableStreamGenericReader.h>
+#include <LibWeb/Streams/UnderlyingSink.h>
 #include <LibWeb/Streams/UnderlyingSource.h>
+#include <LibWeb/Streams/WritableStream.h>
 #include <LibWeb/WebIDL/AbstractOperations.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
 #include <LibWeb/WebIDL/Promise.h>
@@ -734,6 +736,17 @@ WebIDL::ExceptionOr<void> set_up_readable_stream_default_controller_from_underly
     return set_up_readable_stream_default_controller(stream, controller, move(start_algorithm), move(pull_algorithm), move(cancel_algorithm), high_water_mark, move(size_algorithm));
 }
 
+// https://streams.spec.whatwg.org/#is-writable-stream-locked
+bool is_writable_stream_locked(WritableStream const& stream)
+{
+    // 1. If stream.[[writer]] is undefined, return false.
+    if (!stream.writer())
+        return false;
+
+    // 2. Return true.
+    return true;
+}
+
 // Non-standard function to aid in converting a user-provided function into a WebIDL::Callback. This is essentially
 // what the Bindings generator would do at compile time, but at runtime instead.
 JS::ThrowCompletionOr<JS::Handle<WebIDL::CallbackType>> property_to_callback(JS::VM& vm, JS::Value value, JS::PropertyKey const& property_key)