From 5c6125c92b8ff75f5189d39f8e600ab639c48382 Mon Sep 17 00:00:00 2001
From: Kenneth Myhra <kennethmyhra@gmail.com>
Date: Thu, 13 Jul 2023 23:43:20 +0200
Subject: [PATCH] Tests/LibWeb: Add TransformStream start callback test

This test proves the ability of TransformStream to execute
caller supplied code in the start callback, and have access to
TransformStreamDefaultController.
---
 .../TransformStream-start-callback.txt        |  3 +++
 .../TransformStream-start-callback.html       | 20 +++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 Tests/LibWeb/Text/expected/Streams/TransformStream-start-callback.txt
 create mode 100644 Tests/LibWeb/Text/input/Streams/TransformStream-start-callback.html

diff --git a/Tests/LibWeb/Text/expected/Streams/TransformStream-start-callback.txt b/Tests/LibWeb/Text/expected/Streams/TransformStream-start-callback.txt
new file mode 100644
index 0000000000..8cf3b5b555
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/Streams/TransformStream-start-callback.txt
@@ -0,0 +1,3 @@
+In start
+Done: false
+Hello, world!
diff --git a/Tests/LibWeb/Text/input/Streams/TransformStream-start-callback.html b/Tests/LibWeb/Text/input/Streams/TransformStream-start-callback.html
new file mode 100644
index 0000000000..2c94128d2f
--- /dev/null
+++ b/Tests/LibWeb/Text/input/Streams/TransformStream-start-callback.html
@@ -0,0 +1,20 @@
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const {readable} = new TransformStream({
+            start(controller) {
+                println("In start");
+                controller.enqueue("Hello, world!");
+            }
+        });
+        const reader = readable.getReader();
+        reader.read().then(function processText({done, value}) {
+            println(`Done: ${done}`);
+            if (done)
+                return;
+
+            println(value);
+            reader.read().then(processText);
+        });
+    });
+</script>