From c4c80d3dd43bf049362ee4d365fe19a97f5e695f Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@git.wordpress.org>
Date: Fri, 30 Sep 2016 03:15:36 +0000
Subject: [PATCH] Tests: Reset post-related globals after each test.

Globals like `$pages` were leaking between tests, resulting in various
bits of weirdness.

Globals will kill WordPress. Globals are killing WordPress.

See #38196.

git-svn-id: https://develop.svn.wordpress.org/trunk@38678 602fd350-edb4-49c9-b593-d223f7449a82
---
 tests/phpunit/includes/testcase.php      | 10 ++++++++--
 tests/phpunit/tests/includes/helpers.php | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/tests/phpunit/includes/testcase.php b/tests/phpunit/includes/testcase.php
index 1c4d758539..344f9eb331 100644
--- a/tests/phpunit/includes/testcase.php
+++ b/tests/phpunit/includes/testcase.php
@@ -142,7 +142,7 @@ class WP_UnitTestCase extends PHPUnit_Framework_TestCase {
 	 * After a test method runs, reset any state in WordPress the test method might have changed.
 	 */
 	function tearDown() {
-		global $wpdb, $wp_query, $wp, $post;
+		global $wpdb, $wp_query, $wp;
 		$wpdb->query( 'ROLLBACK' );
 		if ( is_multisite() ) {
 			while ( ms_is_switched() ) {
@@ -151,7 +151,13 @@ class WP_UnitTestCase extends PHPUnit_Framework_TestCase {
 		}
 		$wp_query = new WP_Query();
 		$wp = new WP();
-		$post = null;
+
+		// Reset globals related to the post loop and `setup_postdata()`.
+		$post_globals = array( 'post', 'id', 'authordata', 'currentday', 'currentmonth', 'page', 'pages', 'multipage', 'more', 'numpages' );
+		foreach ( $post_globals as $global ) {
+			$GLOBALS[ $global ] = null;
+		}
+
 		remove_theme_support( 'html5' );
 		remove_filter( 'query', array( $this, '_create_temporary_tables' ) );
 		remove_filter( 'query', array( $this, '_drop_temporary_tables' ) );
diff --git a/tests/phpunit/tests/includes/helpers.php b/tests/phpunit/tests/includes/helpers.php
index b035d31672..84ce8ce5b8 100644
--- a/tests/phpunit/tests/includes/helpers.php
+++ b/tests/phpunit/tests/includes/helpers.php
@@ -212,4 +212,27 @@ class Tests_TestHelpers extends WP_UnitTestCase {
 	public function test_die_handler_should_handle_wp_error() {
 		wp_die( new WP_Error( 'test', 'test' ) );
 	}
+
+	/**
+	 * This test is just a setup for the one that follows.
+	 *
+	 * @ticket 38196
+	 */
+	public function test_setup_postdata_globals_should_be_reset_on_teardown__setup() {
+		$post = self::factory()->post->create_and_get();
+		$GLOBALS['wp_query'] = new WP_Query();
+		$GLOBALS['wp_query']->setup_postdata( $post );
+		$this->assertNotEmpty( $post );
+	}
+
+	/**
+	 * @ticket 38196
+	 */
+	public function test_setup_postdata_globals_should_be_reset_on_teardown() {
+		$globals = array( 'post', 'id', 'authordata', 'currentday', 'currentmonth', 'page', 'pages', 'multipage', 'more', 'numpages' );
+
+		foreach ( $globals as $global ) {
+			$this->assertTrue( ! isset( $GLOBALS[ $global ] ), $global );
+		}
+	}
 }