1 files changed, 37 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/stream/bug-1387503-1.js b/js/src/jit-test/tests/stream/bug-1387503-1.js
new file mode 100644
index 0000000000..149d68d51d
--- /dev/null
+++ b/js/src/jit-test/tests/stream/bug-1387503-1.js
@@ -0,0 +1,37 @@
+// Test uncatchable error when a stream source's pull() method is called.
+
+// Make `debugger;` raise an uncatchable error.
+let g = newGlobal({newCompartment: true});
+g.parent = this;
+g.hit = false;
+g.eval(`
+    new Debugger(parent).onDebuggerStatement = _frame => (hit = true, null);
+`);
+
+// Create a stream whose pull() method raises an uncatchable error,
+// and try reading from it.
+let readerCreated = false;
+let fnFinished = false;
+async function fn() {
+    try {
+        let stream = new ReadableStream({
+            start(controller) {},
+            pull(controller) {
+                debugger;
+            }
+        });
+
+        let reader = stream.getReader();
+        let p = reader.read();
+        readerCreated = true;
+        await p;
+    } finally {
+        fnFinished = true;
+    }
+}
+
+fn();
+drainJobQueue();
+assertEq(readerCreated, true);
+assertEq(g.hit, true);
+assertEq(fnFinished, false);