Add tests for get_weekstartend().

Props pbearne, tloureiro.
Fixes #36415.

git-svn-id: https://develop.svn.wordpress.org/trunk@37579 602fd350-edb4-49c9-b593-d223f7449a82

Author: boonebgorges

tests/phpunit/tests/functions/getWeekstartend.php

@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * @group functions.php
+ */
+class Tests_Functions_GetWeekstartend extends WP_UnitTestCase {
+
+	public function test_default_start_of_week_option_is_monday() {
+		$expected = array(
+			'start' => 1454889600,
+			'end'   => 1455494399,
+		);
+
+		$this->assertEquals( $expected, get_weekstartend( '2016-02-12' ) );
+	}
+
+	public function test_start_of_week_sunday() {
+		$expected = array(
+			'start' => 1454803200,
+			'end'   => 1455407999,
+		);
+
+		$this->assertEquals( $expected, get_weekstartend( '2016-02-12', 0 ) );
+	}
+
+	public function test_start_of_week_should_fall_back_on_start_of_week_option() {
+		update_option( 'start_of_week', 2 );
+
+		$expected = array(
+			'start' => 1454976000,
+			'end'   => 1455580799,
+		);
+
+		$this->assertEquals( $expected, get_weekstartend( '2016-02-12' ) );
+	}
+
+	public function test_start_of_week_should_fall_back_on_sunday_when_option_is_missing() {
+		delete_option( 'start_of_week' );
+
+		$expected = array(
+			'start' => 1454803200,
+			'end'   => 1455407999,
+		);
+
+		$this->assertEquals( $expected, get_weekstartend( '2016-02-12' ) );
+	}
+}