1 files changed, 30 insertions, 0 deletions
diff --git a/dom/webidl/FileSystemWritableFileStream.webidl b/dom/webidl/FileSystemWritableFileStream.webidl
new file mode 100644
index 0000000000..a6c2552cb6
--- /dev/null
+++ b/dom/webidl/FileSystemWritableFileStream.webidl
@@ -0,0 +1,30 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+enum WriteCommandType {
+  "write",
+  "seek",
+  "truncate"
+};
+
+[GenerateConversionToJS]
+dictionary WriteParams {
+  required WriteCommandType type;
+  unsigned long long? size;
+  unsigned long long? position;
+  (BufferSource or Blob or UTF8String)? data;
+};
+
+typedef (BufferSource or Blob or UTF8String or WriteParams) FileSystemWriteChunkType;
+
+[Exposed=(Window,Worker), SecureContext, Pref="dom.fs.enabled"]
+interface FileSystemWritableFileStream : WritableStream {
+  [NewObject, Throws]
+  Promise<undefined> write(FileSystemWriteChunkType data);
+  [NewObject]
+  Promise<undefined> seek(unsigned long long position);
+  [NewObject]
+  Promise<undefined> truncate(unsigned long long size);
+};