composer.json

{
    "config": {
        "optimize-autoloader": true
    },
    "repositories": [
        {
            "type": "path",
            "url": "~/st/*",
            "options": {
                "symlink": true
            }
        }
    ],
    "require": {
        "st/strauss-test-package": "^1.0",
        "st/strauss-test-package2": "^1.0"
    },
    "require-dev": {
        "brianhenryie/strauss": "^0.9.0"
    },
    "scripts": {
      "post-install-cmd": [
        "vendor/bin/strauss"
      ],
      "post-update-cmd": [
        "vendor/bin/strauss"
      ]
    },
    "autoload": {
        "psr-4": {
            "StraussTest\\": "strauss/"
        }
    },
    "extra": {
      "strauss": {
          "target_directory": "strauss",
          "namespace_prefix": "StraussTest\\",
          "classmap_prefix": "Strauss_Test_",
          "constant_prefix": "ST_",
          "packages": [
          ],
          "override_autoload": {
          },
          "exclude_from_copy": {
              "packages": [
              ],
              "namespaces": [
              ],
              "file_patterns": [
              ]
          },
          "exclude_from_prefix": {
              "packages": [
              ],
              "namespaces": [
              ],
              "file_patterns": [
                  "/^psr.*$/"
              ]
          },
          "namespace_replacement_patterns" : {
          },
          "delete_vendor_files": false
      }
  }
}

StraussTestPackage (Result).php

<?php
/**
 * @license proprietary
 *
 * Modified by __root__ on 25-June-2021 using Strauss.
 * @see https://github.com/BrianHenryIE/strauss
 */
namespace StraussTest\ST;
class StraussTestPackage {
	public function __construct() {
		new \StraussTest\ST\StraussTestPackage2();
		\ST\StraussTestPackage2::hello();
	}
}

StraussTestPackage.php

<?php
namespace ST;
class StraussTestPackage {
	public function __construct() {
		new \ST\StraussTestPackage2();
		\ST\StraussTestPackage2::hello();
	}
}

StraussTestPackage2.php

<?php
namespace ST;
class StraussTestPackage2 {
	public function __construct() {
		echo 'hello world';
	}
	public static function hello() {
		echo 'hello world';
	}
}