1 files changed, 40 insertions, 0 deletions
diff --git a/js/src/builtin/streams/WritableStreamDefaultWriter-inl.h b/js/src/builtin/streams/WritableStreamDefaultWriter-inl.h
new file mode 100644
index 0000000000..fe85f35bf8
--- /dev/null
+++ b/js/src/builtin/streams/WritableStreamDefaultWriter-inl.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Class WritableStreamDefaultWriter. */
+
+#ifndef builtin_streams_WritableStreamDefaultWriter_inl_h
+#define builtin_streams_WritableStreamDefaultWriter_inl_h
+
+#include "builtin/streams/WritableStreamDefaultWriter.h"
+
+#include "mozilla/Assertions.h"  // MOZ_ASSERT
+#include "mozilla/Attributes.h"  // MOZ_MUST_USE
+
+#include "builtin/streams/WritableStream.h"  // js::WritableStream
+#include "js/RootingAPI.h"                   // JS::Handle
+#include "js/Value.h"                        // JS::ObjectValue
+#include "vm/NativeObject.h"                 // js::NativeObject
+
+#include "vm/Compartment-inl.h"  // js::UnwrapInternalSlot
+
+struct JS_PUBLIC_API JSContext;
+
+namespace js {
+
+/**
+ * Returns the stream associated with the given reader.
+ */
+inline MOZ_MUST_USE WritableStream* UnwrapStreamFromWriter(
+    JSContext* cx, JS::Handle<WritableStreamDefaultWriter*> unwrappedWriter) {
+  MOZ_ASSERT(unwrappedWriter->hasStream());
+  return UnwrapInternalSlot<WritableStream>(
+      cx, unwrappedWriter, WritableStreamDefaultWriter::Slot_Stream);
+}
+
+}  // namespace js
+
+#endif  // builtin_streams_WritableStreamDefaultWriter_inl_h