harness test: promiseHelper.js

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>

test/harness/promiseHelper.js

@@ -0,0 +1,35 @@
+// Copyright (c) 2017 Rick Waldron.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+description: >
+    Including promiseHelper.js will expose a function:
+
+        checkSequence
+
+    To ensure execution order of some async chain, checkSequence accepts an array
+    of numbers, each added during some operation, and verifies that they
+    are in numeric order.
+
+includes: [promiseHelper.js,sta.js]
+---*/
+
+assert(checkSequence([1, 2, 3, 4, 5]));
+
+var threw = false;
+
+try {
+  checkSequence([2, 1, 3, 4, 5]);
+} catch(err) {
+  threw = true;
+  if (err.constructor !== Test262Error) {
+    $ERROR(
+      'Expected a Test262Error, but a "' + err.constructor.name +
+      '" was thrown.'
+    );
+  }
+}
+
+if (threw === false) {
+  $ERROR('Expected a Test262Error, but no error was thrown.');
+}
+