- Refactor WP DateTime helper

- Add a unit test helper to stub out Wordpress functions

tests/unit/WP/DateTimeTest.php

@@ -0,0 +1,82 @@
+<?php
+use \Helper\WordPress as WordPressHelper;
+use \MailPoet\WP\DateTime;
+
+class DateTimeTest extends MailPoetTest {
+  function _before() {
+    $this->date_time = new DateTime();
+  }
+
+  function testGetTimeFormat() {
+    WordPressHelper::interceptFunction('get_option', function($key) {
+      return 'H:i';
+    });
+    expect($this->date_time->getTimeFormat())->equals('H:i');
+
+    WordPressHelper::interceptFunction('get_option', function($key) {
+      return '';
+    });
+    expect($this->date_time->getTimeFormat())->equals('H:i:s');
+  }
+
+  function testGetDateFormat() {
+    WordPressHelper::interceptFunction('get_option', function($key) {
+      return 'm-d';
+    });
+    expect($this->date_time->getDateFormat())->equals('m-d');
+
+    WordPressHelper::interceptFunction('get_option', function($key) {
+      return '';
+    });
+    expect($this->date_time->getDateFormat())->equals('Y-m-d');
+  }
+
+  function testGetCurrentDate() {
+    expect($this->date_time->getCurrentDate("Y-m"))->equals(date("Y-m"));
+  }
+
+  function testGetCurrentTime() {
+    expect($this->date_time->getCurrentTime("i:s"))->regExp('/\d\d:\d\d/');
+  }
+
+  function testFormatTime() {
+    $timestamp = 1234567;
+    $format = "H:i:s";
+    expect($this->date_time->formatTime($timestamp, $format))->equals(date($format, $timestamp));
+  }
+
+  function testTimeInterval() {
+    $one_hour_interval = array_keys($this->date_time->getTimeInterval(
+      '00:00:00',
+      '+1 hour',
+      $total_steps=5
+    ));
+    $one_hour_expected = array(
+      '00:00:00', '01:00:00', '02:00:00', '03:00:00', '04:00:00');
+    expect($one_hour_interval)->equals($one_hour_expected);
+
+    $quarter_hour_interval = array_keys($this->date_time->getTimeInterval(
+      '00:00:00',
+      '+15 minute',
+      $total_steps=5
+    ));
+    $quarter_hour_expected = array(
+      '00:00:00', '00:15:00', '00:30:00', '00:45:00', '01:00:00',
+    );
+    expect($quarter_hour_interval)->equals($quarter_hour_expected);
+
+    $offset_start_time_interval = array_keys($this->date_time->getTimeInterval(
+      '03:00:00',
+      '+1 hour',
+      $total_steps=5
+    ));
+    $offset_start_time_expected = array(
+      '03:00:00', '04:00:00', '05:00:00', '06:00:00', '07:00:00',
+    );
+    expect($offset_start_time_interval)->equals($offset_start_time_expected);
+  }
+
+  function _afterStep() {
+    Wordpress::releaseAllFunctions();
+  }
+}