Add basic date formatter

awx/ui_next/src/util/dates.jsx

@@ -0,0 +1,6 @@
+/* eslint-disable import/prefer-default-export */
+import { getLanguage } from './language';
+
+export function formatDateString(dateString, lang = getLanguage(navigator)) {
+  return new Date(dateString).toLocaleString(lang);
+}

awx/ui_next/src/util/dates.test.jsx

@@ -0,0 +1,13 @@
+import { formatDateString } from './dates';
+
+describe('formatDateString', () => {
+  test('it returns the expected value', () => {
+    const lang = 'en-US';
+    expect(formatDateString('', lang)).toEqual('Invalid Date');
+    expect(formatDateString({}, lang)).toEqual('Invalid Date');
+    expect(formatDateString(undefined, lang)).toEqual('Invalid Date');
+    expect(formatDateString('2018-01-31T01:14:52.969227Z', lang)).toEqual(
+      '1/31/2018, 1:14:52 AM'
+    );
+  });
+});