1 files changed, 53 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/generators/bug1542660.js b/js/src/jit-test/tests/generators/bug1542660.js
new file mode 100644
index 0000000000..b3f3ea4554
--- /dev/null
+++ b/js/src/jit-test/tests/generators/bug1542660.js
@@ -0,0 +1,53 @@
+// |jit-test| skip-if: !('gc' in this) || !('clearKeptObjects' in this)
+// Locals in async functions should not keep objects alive after going out of scope.
+// Test by Mathieu Hofman.
+
+let nextId = 0;
+
+let weakRef;
+let savedCallback;
+
+const tests = [
+  function() {
+    let object = { id: ++nextId };
+    console.log(`created object ${object.id}`);
+    savedCallback = () => {};
+    weakRef = new WeakRef(object);
+  },
+  async function() {
+    let object = { id: ++nextId };
+    console.log(`created object ${object.id}`);
+    savedCallback = () => {};
+    weakRef = new WeakRef(object);
+  },
+  async function() {
+    function* gen() {
+      {
+        let object = { id: ++nextId };
+        console.log(`created object ${object.id}`);
+        // Yielding here stores the local variable `object` in the generator
+        // object.
+        yield 1;
+        weakRef = new WeakRef(object);
+      }
+      // Yielding here should clear it.
+      yield 2;
+    }
+    let iter = gen();
+    assertEq(iter.next().value, 1);
+    assertEq(iter.next().value, 2);
+    savedCallback = iter;  // Keep the generator alive for GC.
+  }
+];
+
+(async () => {
+  for (const test of tests) {
+    await test();
+    assertEq(!!weakRef.deref(), true);
+    clearKeptObjects();
+    gc();
+    if (weakRef.deref()) {
+      throw new Error(`object ${nextId} was not collected`);
+    }
+  }
+})();