1. Installing PHPUnit

Requirements

PHPUnit 9.5 requires PHP 7.3; using the latest version of PHP is highly recommended.

PHPUnit requires the dom and json extensions, which are normally enabled by default.

PHPUnit also requires the pcre, reflection, and spl extensions. These standard extensions are enabled by default and cannot be disabled without patching PHP’s build system and/or C sources.

The code coverage report feature requires the Xdebug (2.7.0 or later) and tokenizer extensions. Generating XML reports requires the xmlwriter extension.

PHP Archive (PHAR)

The easiest way to obtain PHPUnit is to download a PHP Archive (PHAR) that has all required (as well as some optional) dependencies of PHPUnit bundled in a single file.

The phar extension is required for using PHP Archives (PHAR).

If the Suhosin extension is enabled, you need to allow execution of PHARs in your php.ini:

  1. suhosin.executor.include.whitelist = phar

The PHPUnit PHAR can be used immediately after download:

  1. $ wget https://phar.phpunit.de/phpunit-9.5.phar
  2. $ php phpunit-9.5.phar --version
  3. PHPUnit x.y.z by Sebastian Bergmann and contributors.

It is a common practice to make the PHAR executable:

  1. $ wget https://phar.phpunit.de/phpunit-9.5.phar
  2. $ chmod +x phpunit-9.5.phar
  3. $ ./phpunit-9.5.phar --version
  4. PHPUnit x.y.z by Sebastian Bergmann and contributors.

Verifying PHPUnit PHAR Releases

All official releases of code distributed by the PHPUnit Project are signed by the release manager for the release. PGP signatures and SHA256 hashes are available for verification on phar.phpunit.de.

The following example details how release verification works. We start by downloading phpunit.phar as well as its detached PGP signature phpunit.phar.asc:

  1. $ wget https://phar.phpunit.de/phpunit-9.5.phar
  2. $ wget https://phar.phpunit.de/phpunit-9.5.phar.asc

We want to verify PHPUnit’s PHP Archive (phpunit-x.y.phar) against its detached signature (phpunit-x.y.phar.asc):

  1. $ gpg phpunit-9.5.phar.asc
  2. gpg: Signature made Sat 19 Jul 2014 01:28:02 PM CEST using RSA key ID 6372C20A
  3. gpg: Can't check signature: public key not found

We don’t have the release manager’s public key (6372C20A) in our local system. In order to proceed with the verification we need to retrieve the release manager’s public key from a key server. One such server is pgp.uni-mainz.de. The public key servers are linked together, so you should be able to connect to any key server.

  1. $ curl --silent https://sebastian-bergmann.de/gpg.asc | gpg --import
  2. gpg: key 4AA394086372C20A: 452 signatures not checked due to missing keys
  3. gpg: /root/.gnupg/trustdb.gpg: trustdb created
  4. gpg: key 4AA394086372C20A: public key "Sebastian Bergmann <sb@sebastian-bergmann.de>" imported
  5. gpg: Total number processed: 1
  6. gpg:               imported: 1
  7. gpg: no ultimately trusted keys found

Now we have received a public key for an entity known as “Sebastian Bergmann <sb@sebastian-bergmann.de>”. However, we have no way of verifying this key was created by the person known as Sebastian Bergmann. But, let’s try to verify the release signature again.

  1. $ gpg phpunit-9.5.phar.asc
  2. gpg: Signature made Sat 19 Jul 2014 01:28:02 PM CEST using RSA key ID 6372C20A
  3. gpg: Good signature from "Sebastian Bergmann <sb@sebastian-bergmann.de>"
  4. gpg:                 aka "Sebastian Bergmann <sebastian@php.net>"
  5. gpg:                 aka "Sebastian Bergmann <sebastian@thephp.cc>"
  6. gpg:                 aka "Sebastian Bergmann <sebastian@phpunit.de>"
  7. gpg:                 aka "Sebastian Bergmann <sebastian.bergmann@thephp.cc>"
  8. gpg:                 aka "[jpeg image of size 40635]"
  9. gpg: WARNING: This key is not certified with a trusted signature!
  10. gpg:          There is no indication that the signature belongs to the owner.
  11. Primary key fingerprint: D840 6D0D 8294 7747 2937  7831 4AA3 9408 6372 C20A

At this point, the signature is good, but we don’t trust this key. A good signature means that the file has not been tampered. However, due to the nature of public key cryptography, you need to additionally verify that key 6372C20A was created by the real Sebastian Bergmann.

Any attacker can create a public key and upload it to the public key servers. They can then create a malicious release signed by this fake key. Then, if you tried to verify the signature of this corrupt release, it would succeed because the key was not the “real” key. Therefore, you need to validate the authenticity of this key. Validating the authenticity of a public key, however, is outside the scope of this documentation.

Manually verifying the authenticity and integrity of a PHPUnit PHAR using GPG is tedious. This is why PHIVE, the PHAR Installation and Verification Environment, was created. You can learn about PHIVE on its website

Composer

Add a (development-time) dependency on phpunit/phpunit to your project’s composer.json file if you use Composer to manage the dependencies of your project:

  1. composer require --dev phpunit/phpunit ^9.5

Global Installation

Please note that it is not recommended to install PHPUnit globally, as /usr/bin/phpunit or /usr/local/bin/phpunit, for instance.

Instead, PHPUnit should be managed as a project-local dependency.

Either put the PHAR of the specific PHPUnit version you need in your project’s tools directory (which should be managed by PHIVE) or depend on the specific PHPUnit version you need in your project’s composer.json if you use Composer.

Webserver

PHPUnit is a framework for writing as well as a commandline tool for running tests. Writing and running tests is a development-time activity. There is no reason why PHPUnit should be installed on a webserver.

If you upload PHPUnit to a webserver then your deployment process is broken. On a more general note, if your vendor directory is publicly accessible on your webserver then your deployment process is also broken.

Please note that if you upload PHPUnit to a webserver “bad things” may happen. You have been warned.