wordpress-develop/tests/phpunit/tests/functions/getWeekstartend.php

<?php

/**
 * @group functions.php
 * @covers ::get_weekstartend
 */
class Tests_Functions_GetWeekstartend extends WP_UnitTestCase {

	public function test_default_start_of_week_option_is_monday() {
		$expected = array(
			'start' => 1454889600,
			'end'   => 1455494399,
		);

		$this->assertSame( $expected, get_weekstartend( '2016-02-12' ) );
	}

	public function test_start_of_week_sunday() {
		$expected = array(
			'start' => 1454803200,
			'end'   => 1455407999,
		);

		$this->assertSame( $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->assertSame( $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->assertSame( $expected, get_weekstartend( '2016-02-12' ) );
	}
}