From e2c4019bfcc1b16b802c82ab2f3858cf4aba2794 Mon Sep 17 00:00:00 2001
From: Kenneth Myhra <kennethmyhra@gmail.com>
Date: Mon, 20 May 2024 10:42:33 +0200
Subject: [PATCH] LibWeb: Close acquired writer in AO readable_stream_pipe_to()

Also adds a test to prove that the WritableStream's close callback is
called.
---
 ...am-pipeTo-Writer-close-callback-called.txt |  1 +
 ...m-pipeTo-Writer-close-callback-called.html | 20 +++++++++++++++++++
 .../LibWeb/Streams/AbstractOperations.cpp     | 10 ++++++++--
 3 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/Streams/ReadableStream-pipeTo-Writer-close-callback-called.txt
 create mode 100644 Tests/LibWeb/Text/input/Streams/ReadableStream-pipeTo-Writer-close-callback-called.html

diff --git a/Tests/LibWeb/Text/expected/Streams/ReadableStream-pipeTo-Writer-close-callback-called.txt b/Tests/LibWeb/Text/expected/Streams/ReadableStream-pipeTo-Writer-close-callback-called.txt
new file mode 100644
index 00000000000000..2ffe46565bab34
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/Streams/ReadableStream-pipeTo-Writer-close-callback-called.txt
@@ -0,0 +1 @@
+Writer has been closed.
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/Streams/ReadableStream-pipeTo-Writer-close-callback-called.html b/Tests/LibWeb/Text/input/Streams/ReadableStream-pipeTo-Writer-close-callback-called.html
new file mode 100644
index 00000000000000..b6cd67d13ed77a
--- /dev/null
+++ b/Tests/LibWeb/Text/input/Streams/ReadableStream-pipeTo-Writer-close-callback-called.html
@@ -0,0 +1,20 @@
+<script src="../include.js"></script>
+<script>
+    asyncTest(done => {
+        const writableStream = new WritableStream({
+                close() {
+                    println("Writer has been closed.");
+                }
+            }
+        );
+        const stream = new ReadableStream({
+            pull(controller) {
+                controller.close();
+            }
+        });
+
+        stream.pipeTo(writableStream).then(() => {
+            done();
+        });
+    });
+</script>
diff --git a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
index 5ad849e153295d..731968e2ea4ed2 100644
--- a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
+++ b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
@@ -314,11 +314,17 @@ JS::NonnullGCPtr<WebIDL::Promise> readable_stream_pipe_to(ReadableStream& source
         WebIDL::resolve_promise(realm, promise, JS::js_undefined());
     };
 
-    auto success_steps = [promise, &realm](ByteBuffer) {
+    auto success_steps = [promise, &realm, writer](ByteBuffer) {
+        // Make sure we close the acquired writer.
+        WebIDL::resolve_promise(realm, writable_stream_default_writer_close(*writer), JS::js_undefined());
+
         WebIDL::resolve_promise(realm, promise, JS::js_undefined());
     };
 
-    auto failure_steps = [promise, &realm](JS::Value error) {
+    auto failure_steps = [promise, &realm, writer](JS::Value error) {
+        // Make sure we close the acquired writer.
+        WebIDL::resolve_promise(realm, writable_stream_default_writer_close(*writer), JS::js_undefined());
+
         WebIDL::reject_promise(realm, promise, error);
     };