Hack around PHP 7.3 polyfill scoping

.travis.yml

@@ -60,8 +60,8 @@ jobs:
         - vendor/bin/phpcs
 
     - stage: Phar build
-      php: 7.2
-      env: DEPS="low"
+      php: 7.3
+      env: DEPS="high"
       script: bin/build-phar.sh
       deploy:
         # deploy tagged releases to github releases page

bin/build-phar.sh

@@ -4,6 +4,10 @@ set -e
 
 composer bin box install
 
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+
+php $DIR/improve_class_alias.php
+
 vendor/bin/box compile
 
 if [[ "$GPG_ENCRYPTION" != '' ]] ; then

bin/improve_class_alias.php

@@ -0,0 +1,36 @@
+<?php
+
+$vendor_path = 'vendor-bin/box/vendor/humbug/php-scoper/src/PhpParser/NodeVisitor/ClassAliasStmtAppender.php';
+
+if (!file_exists($vendor_path)) {
+    die('Vendor file does not exist' . PHP_EOL);
+}
+
+$search = '/* @var FullyQualified $originalName */
+
+        $stmts[] = $this->createAliasStmt($originalName, $stmt);';
+
+$replace = '/* @var FullyQualified $originalName */
+        $aliasStmt = $this->createAliasStmt($originalName, $stmt);
+
+        $stmts[] = new If_(
+            new FuncCall(
+                new FullyQualified(\'class_exists\'),
+                [
+                    new Node\Arg(
+                        new Node\Expr\ClassConstFetch(
+                            $originalName,
+                            \'class\'
+                        )
+                    )
+                ]
+            ),
+            [\'stmts\' => [$aliasStmt]]
+        );';
+
+$contents = file_get_contents($vendor_path);
+
+$contents = str_replace($search, $replace, $contents);
+
+file_put_contents($vendor_path, $contents);
+