Add option to jest to run tests only locally, or on linux (#2609)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/2609

Make it possible to mark some tests to run on non-CI, or unix only

Reviewed By: nikoant

Differential Revision: D29813506

fbshipit-source-id: 140f8a4eaed5af3282ab9d139b46a52818be0934

desktop/scripts/jest-setup-after.js

@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+// jest-setup-after will run after Jest has been initialized, so that it can be adapted.
+
+const test = global.test;
+if (!test) {
+  throw new Error('Failed jest test object');
+}
+/**
+ * This test will not be executed on Github / SandCastle,
+ * since, for example, it relies on precise timer reliability
+ */
+test.local = function local() {
+  const fn = process.env.SANDCASTLE || process.env.CI ? test.skip : test;
+  // eslint-disable-next-line
+  return fn.apply(null, arguments);
+};
+
+/**
+ * This test will only run on non-windows machines
+ */
+test.unix = function local() {
+  const fn = process.platform === 'win32' ? test.skip : test;
+  // eslint-disable-next-line
+  return fn.apply(null, arguments);
+};