1 files changed, 44 insertions, 0 deletions
diff --git a/dom/streams/test/xpcshell/bug-1387503-1.js b/dom/streams/test/xpcshell/bug-1387503-1.js
new file mode 100644
index 0000000000..777f614c44
--- /dev/null
+++ b/dom/streams/test/xpcshell/bug-1387503-1.js
@@ -0,0 +1,44 @@
+// Test uncatchable error when a stream source's pull() method is called.
+let readerCreated = false;
+let fnFinished = false;
+let g;
+
+add_task(async function test() {
+  // Make `debugger;` raise an uncatchable error.
+  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.
+
+  async function fn() {
+    try {
+      let stream = new ReadableStream({
+        start(controller) {},
+        pull(controller) {
+          // eslint-disable-next-line no-debugger
+          debugger;
+        },
+      });
+
+      let reader = stream.getReader();
+      let p = reader.read();
+      readerCreated = true;
+      await p;
+    } finally {
+      fnFinished = true;
+    }
+  }
+
+  fn();
+});
+
+add_task(() => {
+  equal(readerCreated, true);
+  equal(g.hit, true);
+  equal(fnFinished, false);
+});