PHP-Scoper

PHP-Scoper is a tool which essentially moves any body of code, including all
dependencies such as vendor directories, to a new and distinct namespace.

Goal

PHP-Scoper's goal is to make sure that all code for a project lies in a
distinct PHP namespace. This is necessary, for example, when building PHARs that:

• Bundle their own vendor dependencies; and
• Load/execute code from arbitrary PHP projects with similar dependencies

When a package (of possibly different versions) exists, and is found in both a PHAR
and the executed code, the one from the PHAR will be used. This means these
PHARs run the risk of raising conflicts between their bundled vendors and the
vendors of the project they are interacting with, leading to issues that are
potentially very difficult to debug due to dissimilar or unsupported package versions.

Table of Contents

• Installation
  • Phive
  • Composer
  • Docker
  • GitHub
• Usage
• Configuration
  • Prefix
  • PHP Version
  • Output directory
  • Finders and paths
  • Patchers
  • Excluded files
  • Excluded Symbols
  • Excluding namespaces
  • Exposed Symbols
    • Exposing namespaces
    • Exposing classes
    • Exposing functions
    • Exposing constants
• Building a scoped PHAR
  • With Box
  • Without Box
    • Step 1: Configure build location and prep vendors
    • Step 2: Run PHP-Scoper
• Recommendations
• Debugging
• Further Reading
  • How to deal with unknown third-party symbols
  • Autoload aliases
    • Class aliases
    • Function aliases
  • Laravel support
  • Symfony support
  • Wordpress support
• Limitations
  • Dynamic symbols
  • Date symbols
  • Heredoc values
  • Callables
  • String values
  • Native functions and constants shadowing
  • Composer Autoloader
  • Composer Plugins
  • PSR-0 Partial support
  • Files autoloading
  • Exposing/Excluding traits
  • Exposing/Excluding enums
• Contributing
• Credits

Usage

bashCopy
php-scoper add-prefix

This will prefix all relevant namespaces in code found in the current working
directory. The prefixed files will be accessible in a build folder. You can
then use the prefixed code to build your PHAR.

Warning: After prefixing the files, if you are relying on Composer
for the auto-loading, dumping the autoloader again is required.

For a more concrete example, you can take a look at PHP-Scoper's build
step in Makefile, especially if you are using Composer as
there are steps both before and after running PHP-Scoper to consider.

Refer to TBD for an in-depth look at scoping and building a PHAR taken from
PHP-Scoper's makefile.

Building a Scoped PHAR

With Box

If you are using Box to build your PHAR, you can use the existing
PHP-Scoper integration. Box will take care of
most of the things for you so you should only have to adjust the PHP-Scoper
configuration to your needs.

Without Box

Step 1: Configure build location and prep vendors

Assuming you do not need any development dependencies, run:

bashCopy
composer install --no-dev --prefer-dist

This will allow you to save time in the scoping process by not
processing unnecessary files.

Step 2: Run PHP-Scoper

PHP-Scoper copies code to a new location during prefixing, leaving your original
code untouched. The default location is ./build. You can change the default
location using the --output-dir option. By default, it also generates a random
prefix string. You can set a specific prefix string using the --prefix option.
If automating builds, you can set the --force option to overwrite any code
existing in the output directory without being asked to confirm.

Onto the basic command assuming default options from your project's root
directory:

bashCopy
bin/php-scoper add-prefix

As there are no path arguments, the current working directory will be scoped to
./build in its entirety. Of course, actual prefixing is limited to PHP files,
or PHP scripts. Other files are copied unchanged, though we also need to scope
certain Composer related files.

Speaking of scoping Composer related files... The next step is to dump the
Composer autoloader if we depend on it, so everything works as expected:

bashCopy
composer dump-autoload --working-dir build --classmap-authoritative

Recommendations

There is 3 things to manage when dealing with isolated PHARs:

• The PHAR format: there is some incompatibilities such as realpath() which
  will no longer work for the files within the PHAR since the paths are not
  virtual.
• Isolating the code: due to the dynamic nature of PHP, isolating your
  dependencies will never be a trivial task and as a result you should have
  some end-to-end test to ensure your isolated code is working properly. You
  will also likely need to configure the excluded and exposed symbols or
  patchers.
• The dependencies: which dependencies are you shipping? Fine controlled ones
  managed with a composer.lock or you always ship your application with
  up-to-date dependencies? The latter, although more ideal, will by design
  result in more brittleness as any new release from a dependency may break
  something (although the changes may be SemVer compliant, we are dealing with
  PHARs and isolated code)

As a result, you should have end-to-end tests for your (at the minimum) your
released PHAR.

Since dealing with the 3 issues mentioned above at once can be tedious, it is
highly recommended having several tests for each step.

For example, you can have a test for both your non-isolated PHAR and your
isolated PHAR, this way you will know which step is causing an issue. If the
isolated PHAR is not working, you can try to test the isolated code directly
outside the PHAR to make sure the scoping process is not the issue.

To check if the isolated code is working correctly, you have a number of solutions:

• When using PHP-Scoper directly, by default PHP-Scoper dump the files in a
  build directory. Do not forget that
  you need to dump the Composer autoloader for the isolated code to work!.
• When using Box, you can use its --debug option from the compile
  command in order to have the code shipped in the PHAR dumped in the .box
  directory.
• When using a PHAR (created by Box or any other PHAR building tool),
  you can use the Phar::extractTo() method.

Debugging

Having a good breakdown like described in Recommendations will help
to know where the issue is coming from. However, if you have a doubt or you are fiddling
with patchers and want to check the result for a specific file without doing the whole
scoping process, you can always check the result for that single individual file:

shellCopy
php-scoper inspect path/to/my-file.php

Contributing

Contribution Guide

Credits

Project originally created by: Bernhard Schussek (@webmozart) which has
now been moved under the
Humbug umbrella.