diff --git a/js/src/tests/ecma_7/AsyncFunctions/shell.js b/js/src/tests/ecma_7/AsyncFunctions/shell.js
index e69de29bb2d1..caee5ff7ef69 100644
--- a/js/src/tests/ecma_7/AsyncFunctions/shell.js
+++ b/js/src/tests/ecma_7/AsyncFunctions/shell.js
@@ -0,0 +1,26 @@
+(function(global) {
+  function getPromiseResult(promise) {
+    var result, error, caught = false;
+    promise.then(r => { result = r; },
+                 e => { caught = true; error = e; });
+    drainJobQueue();
+    if (caught)
+      throw error;
+    return result;
+  }
+
+  function assertEventuallyEq(promise, expected) {
+    assertEq(getPromiseResult(promise), expected);
+  }
+  global.assertEventuallyEq = assertEventuallyEq;
+
+  function assertEventuallyThrows(promise, expectedErrorType) {
+    assertThrowsInstanceOf(() => getPromiseResult(promise), expectedErrorType);
+  };
+  global.assertEventuallyThrows = assertEventuallyThrows;
+
+  function assertEventuallyDeepEq(promise, expected) {
+    assertDeepEq(getPromiseResult(promise), expected);
+  };
+  global.assertEventuallyDeepEq = assertEventuallyDeepEq;
+})(this);