REST API: Fix the client test fixture generation in PHP 5.2 and 5.3.

Remove `JSON_UNESCAPED_SLASHES` from the `wp_json_encode` call - this constant is not supported in PHP < 5.4, and we don't polyfill it either.

Also make the PHPUnit test suite correctly exit with a non-zero exit code when `wp-tests-config.php` is not present.  This was causing `grunt restapi-jsclient` to incorrectly proceed to its second step even when the first step failed with this error.

Props ocean90.
Fixes #39264.


git-svn-id: https://develop.svn.wordpress.org/trunk@40065 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/includes/bootstrap.php

@@ -18,8 +18,9 @@ $config_file_path .= '/wp-tests-config.php';
  */
 global $wpdb, $current_site, $current_blog, $wp_rewrite, $shortcode_tags, $wp, $phpmailer, $wp_theme_directories;
 
-if ( !is_readable( $config_file_path ) ) {
-	die( "ERROR: wp-tests-config.php is missing! Please use wp-tests-config-sample.php to create a config file.\n" );
+if ( ! is_readable( $config_file_path ) ) {
+	echo "ERROR: wp-tests-config.php is missing! Please use wp-tests-config-sample.php to create a config file.\n";
+	exit( 1 );
 }
 require_once $config_file_path;
 require_once dirname( __FILE__ ) . '/functions.php';

tests/phpunit/tests/rest-api/rest-schema-setup.php

@@ -277,7 +277,7 @@ class WP_Test_REST_Schema_Initialization extends WP_Test_REST_TestCase {
 
 			$fixture = $this->normalize_fixture( $data, $route['name'] );
 			$mocked_responses .= "\nmockedApiResponse." . $route['name'] . ' = '
-				. json_encode( $fixture, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES )
+				. json_encode( $fixture, JSON_PRETTY_PRINT )
 				. ";\n";
 		}