1 files changed, 28 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_ReadableStream_from.js b/js/xpconnect/tests/unit/test_ReadableStream_from.js
new file mode 100644
index 0000000000..b4ecf25123
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_ReadableStream_from.js
@@ -0,0 +1,28 @@
+/* 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/. */
+
+add_task(async function run_test() {
+  let sb = new Cu.Sandbox('http://www.example.com');
+
+  let done = false;
+  let iterator = {
+    [Symbol.asyncIterator]() {
+      return this;
+    },
+
+    next() {
+      let promise = Cu.evalInSandbox(`Promise.resolve({done: ${done}, value: {hello: "world"}})`, sb);
+      done = true;
+      return promise;
+    }
+  }
+
+  let stream = ReadableStream.from(iterator);
+  let reader = stream.getReader();
+  let result = await reader.read();
+  Assert.equal(result.done, false);
+  Assert.equal(result.value?.hello, "world");
+  result = await reader.read();
+  Assert.equal(result.done, true);
+});