REST API: Sanitize arrays being sent as CSVs.

In #38586 the ability to parse arrays as csv was introduced, however it didn't add any support for validating csv arrays. This adds such sanitization, and also a good amount of unit tests for all sanitization baed off schema.

See #38586.


git-svn-id: https://develop.svn.wordpress.org/trunk@39061 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api.php

@@ -1097,6 +1097,9 @@ function rest_sanitize_value_from_schema( $value, $args ) {
 		if ( empty( $args['items'] ) ) {
 			return (array) $value;
 		}
+		if ( ! is_array( $value ) ) {
+			$value = preg_split( '/[\s,]+/', $value );
+		}
 		foreach ( $value as $index => $v ) {
 			$value[ $index ] = rest_sanitize_value_from_schema( $v, $args['items'] );
 		}