fix: Configure the printer PHP version to 7.2 by default (#1049)

See the discussion in nikic/PHP-Parser#1007.

This should fix sebastianbergmann/phpunit#5855 although this may result in more ugly code formatting than desired. For this reason the default printer version is 7.2 rather than 5.3 as it would make the code too otherwise.

Author: theofidry

docs/configuration.md

@@ -60,11 +60,19 @@ then a random prefix will be automatically generated.
 
 ### PHP Version
 
-The PHP version provided is used to configure the underlying [PHP-Parser] Parser and Printer. This will not affect
-the PHP internal symbols used by PHP-Scoper but may affect what code can be parsed and how the code will be printed.
+The PHP version provided is used to configure the underlying [PHP-Parser] Parser and Printer. 
 
-If `null` or `''` (empty string) is given, then the host version will be used, i.e. executing it with PHP 8.4 will
-result in PHP 8.4 being used as the PHP version. 
+The version used by the Parser will affect what code it can understand, e.g. if it is configured in PHP 8.2 it will not
+understand a PHP 8.3 construct (e.g. typed class constants). However, what symbols are interpreted as internal will
+remain unchanged. The function `json_validate()` will be considered as internal even if the parser is configured with
+PHP 8.2.
+
+The printer version affects the code style. For example nowdocs and heredocs will be indented if the printer's PHP
+version is higher than 7.4 but will be formated without indent otherwise.
+
+If `null` or `''` (empty string) is given, then the host version will be used for the parser and 7.2 will be used for
+the printer. This allows PHP-Scoper to a PHP 7.2 compatible codebase without breaking its compatibility although the
+host version is a newer version.
 
 
 ### Output directory

phpstan.neon.dist

@@ -61,5 +61,3 @@ parameters:
         # Fixed in https://github.com/nikic/PHP-Parser/pull/1003
         - message: '#Standard constructor expects array#'
           path: 'src/Container.php'
-        - message: '#Standard constructor expects array#'
-          path: 'src/PhpParser/Printer/StandardPrinterFactory.php'

src/PhpParser/Printer/StandardPrinterFactory.php

@@ -23,7 +23,7 @@ public function createPrinter(?PhpVersion $phpVersion = null): Printer
     {
         return new StandardPrinter(
             new Standard([
-                'phpVersion' => $phpVersion,
+                'phpVersion' => $phpVersion ?? PhpVersion::fromComponents(7, 2),
             ]),
         );
     }