Scripts#

What is a script?#

A script, in Composer's terms, can either be a PHP callback (defined as a static method) or any command-line executable command. Scripts are useful for executing a package's custom code or package-specific commands during the Composer execution process.

As of Composer 2.5 scripts can also be Symfony Console Command classes, which allows you to easily run them including passing options. This is however not recommended for handling events.

Note: Only scripts defined in the root package's composer.json are executed. If a dependency of the root package specifies its own scripts, Composer does not execute those additional scripts.

Event names#

Composer fires the following named events during its execution process:

Command Events#

  • pre-install-cmd: occurs before the install command is executed with a lock file present.
  • post-install-cmd: occurs after the install command has been executed with a lock file present.
  • pre-update-cmd: occurs before the update command is executed, or before the install command is executed without a lock file present.
  • post-update-cmd: occurs after the update command has been executed, or after the install command has been executed without a lock file present.
  • pre-status-cmd: occurs before the status command is executed.
  • post-status-cmd: occurs after the status command has been executed.
  • pre-archive-cmd: occurs before the archive command is executed.
  • post-archive-cmd: occurs after the archive command has been executed.
  • pre-autoload-dump: occurs before the autoloader is dumped, either during install/update, or via the dump-autoload command.
  • post-autoload-dump: occurs after the autoloader has been dumped, either during install/update, or via the dump-autoload command.
  • post-root-package-install: occurs after the root package has been installed during the create-project command (but before its dependencies are installed).
  • post-create-project-cmd: occurs after the create-project command has been executed.

Installer Events#

  • pre-operations-exec: occurs before the install/upgrade/.. operations are executed when installing a lock file. Plugins that need to hook into this event will need to be installed globally to be usable, as otherwise they would not be loaded yet when a fresh install of a project happens.

Package Events#

  • pre-package-install: occurs before a package is installed.
  • post-package-install: occurs after a package has been installed.
  • pre-package-update: occurs before a package is updated.
  • post-package-update: occurs after a package has been updated.
  • pre-package-uninstall: occurs before a package is uninstalled.
  • post-package-uninstall: occurs after a package has been uninstalled.

Plugin Events#

  • init: occurs after a Composer instance is done being initialized.
  • command: occurs before any Composer Command is executed on the CLI. It provides you with access to the input and output objects of the program.
  • pre-file-download: occurs before files are downloaded and allows you to manipulate the HttpDownloader object prior to downloading files based on the URL to be downloaded.
  • post-file-download: occurs after package dist files are downloaded and allows you to perform additional checks on the file if required.
  • pre-command-run: occurs before a command is executed and allows you to manipulate the InputInterface object's options and arguments to tweak a command's behavior.
  • pre-pool-create: occurs before the Pool of packages is created, and lets you filter the list of packages that is going to enter the Solver.

Note: Composer makes no assumptions about the state of your dependencies prior to install or update. Therefore, you should not specify scripts that require Composer-managed dependencies in the pre-update-cmd or pre-install-cmd event hooks. If you need to execute scripts prior to install or update please make sure they are self-contained within your root package.

Defining scripts#

The root JSON object in composer.json should have a property called "scripts", which contains pairs of named events and each event's corresponding scripts. An event's scripts can be defined as either a string (only for a single script) or an array (for single or multiple scripts.)

For any given event:

  • Scripts execute in the order defined when their corresponding event is fired.
  • An array of scripts wired to a single event can contain both PHP callbacks and command-line executable commands.
  • PHP classes and commands containing defined callbacks must be autoloadable via Composer's autoload functionality.
  • Callbacks can only autoload classes from psr-0, psr-4 and classmap definitions. If a defined callback relies on functions defined outside of a class, the callback itself is responsible for loading the file containing these functions.

Script definition example:

{
    "scripts": {
        "post-update-cmd": "MyVendor\\MyClass::postUpdate",
        "post-package-install": [
            "MyVendor\\MyClass::postPackageInstall"
        ],
        "post-install-cmd": [
            "MyVendor\\MyClass::warmCache",
            "phpunit -c app/"
        ],
        "post-autoload-dump": [
            "MyVendor\\MyClass::postAutoloadDump"
        ],
        "post-create-project-cmd": [
            "php -r \"copy('config/local-example.php', 'config/local.php');\""
        ]
    }
}

Using the previous definition example, here's the class MyVendor\MyClass that might be used to execute the PHP callbacks:

<?php

namespace MyVendor;

use Composer\Script\Event;
use Composer\Installer\PackageEvent;

class MyClass
{
    public static function postUpdate(Event $event)
    {
        $composer = $event->getComposer();
        // do stuff
    }

    public static function postAutoloadDump(Event $event)
    {
        $vendorDir = $event->getComposer()->getConfig()->get('vendor-dir');
        require $vendorDir . '/autoload.php';

        some_function_from_an_autoloaded_file();
    }

    public static function postPackageInstall(PackageEvent $event)
    {
        $installedPackage = $event->getOperation()->getPackage();
        // do stuff
    }

    public static function warmCache(Event $event)
    {
        // make cache toasty
    }
}

Note: During a Composer install or update command run, a variable named COMPOSER_DEV_MODE will be added to the environment. If the command was run with the --no-dev flag, this variable will be set to 0, otherwise it will be set to 1. The variable is also available while dump-autoload runs, and it will be set to the same as the last install or update was run in.

Event classes#

When an event is fired, your PHP callback receives as first argument a Composer\EventDispatcher\Event object. This object has a getName() method that lets you retrieve the event name.

Depending on the script types you will get various event subclasses containing various getters with relevant data and associated objects:

Running scripts manually#

If you would like to run the scripts for an event manually, the syntax is:

php composer.phar run-script [--dev] [--no-dev] script

For example composer run-script post-install-cmd will run any post-install-cmd scripts and plugins that have been defined.

You can also give additional arguments to the script handler by appending -- followed by the handler arguments. e.g. composer run-script post-install-cmd -- --check will pass--check along to the script handler. Those arguments are received as CLI arg by CLI handlers, and can be retrieved as an array via $event->getArguments() by PHP handlers.

Writing custom commands#

If you add custom scripts that do not fit one of the predefined event name above, you can either run them with run-script or also run them as native Composer commands. For example the handler defined below is executable by running composer test:

{
    "scripts": {
        "test": "phpunit",
        "do-something": "MyVendor\\MyClass::doSomething"
        "my-cmd": "MyVendor\\MyCommand"
    }
}

Similar to the run-script command you can give additional arguments to scripts, e.g. composer test -- --filter <pattern> will pass --filter <pattern> along to the phpunit script.

Using a PHP method via composer do-something arg lets you execute a static function doSomething(\Composer\Script\Event $event) and arg becomes available in $event->getArguments(). This however does not let you easily pass custom options in the form of --flags.

Using a symfony/console Command class you can define and access arguments and options more easily.

For example with the command below you can then simply call composer my-cmd --arbitrary-flag without even the need for a -- separator. To be detected as symfony/console commands the class name must end with Command and extend symfony's Command class. Also note that this will run using Composer's built-in symfony/console version which may not match the one you have required in your project, and may change between Composer minor releases. If you need more safety guarantees you should rather use your own binary file that runs your own symfony/console version in isolation in its own process then.

<?php

namespace MyVendor;

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;

class MyCommand extends Command
{
    protected function configure(): void
    {
        $this->setDefinition([
            new InputOption('arbitrary-flag', null, InputOption::VALUE_NONE, 'Example flag'),
            new InputArgument('foo', InputArgument::OPTIONAL, 'Optional arg'),
        ]);
    }

    public function execute(InputInterface $input, OutputInterface $output): int
    {
        if ($input->getOption('arbitrary-flag')) {
            $output->writeln('The flag was used');
        }

        return 0;
    }
}

Note: Before executing scripts, Composer's bin-dir is temporarily pushed on top of the PATH environment variable so that binaries of dependencies are directly accessible. In this example no matter if the phpunit binary is actually in vendor/bin/phpunit or bin/phpunit it will be found and executed.

Managing the process timeout#

Although Composer is not intended to manage long-running processes and other such aspects of PHP projects, it can sometimes be handy to disable the process timeout on custom commands. This timeout defaults to 300 seconds and can be overridden in a variety of ways depending on the desired effect:

  • disable it for all commands using the config key process-timeout,
  • disable it for the current or future invocations of composer using the environment variable COMPOSER_PROCESS_TIMEOUT,
  • for a specific invocation using the --timeout flag of the run-script command,
  • using a static helper for specific scripts.

To disable the timeout for specific scripts with the static helper directly in composer.json:

{
    "scripts": {
        "test": [
            "Composer\\Config::disableProcessTimeout",
            "phpunit"
        ]
    }
}

To disable the timeout for every script on a given project, you can use the composer.json configuration:

{
    "config": {
        "process-timeout": 0
    }
}

It's also possible to set the global environment variable to disable the timeout of all following scripts in the current terminal environment:

export COMPOSER_PROCESS_TIMEOUT=0

To disable the timeout of a single script call, you must use the run-script composer command and specify the --timeout parameter:

php composer.phar run-script --timeout=0 test

Referencing scripts#

To enable script re-use and avoid duplicates, you can call a script from another one by prefixing the command name with @:

{
    "scripts": {
        "test": [
            "@clearCache",
            "phpunit"
        ],
        "clearCache": "rm -rf cache/*"
    }
}

You can also refer a script and pass it new arguments:

{
    "scripts": {
        "tests": "phpunit",
        "testsVerbose": "@tests -vvv"
    }
}

Calling Composer commands#

To call Composer commands, you can use @composer which will automatically resolve to whatever composer.phar is currently being used:

{
    "scripts": {
        "test": [
            "@composer install",
            "phpunit"
        ]
    }
}

One limitation of this is that you can not call multiple composer commands in a row like @composer install && @composer foo. You must split them up in a JSON array of commands.

Executing PHP scripts#

To execute PHP scripts, you can use @php which will automatically resolve to whatever php process is currently being used:

{
    "scripts": {
        "test": [
            "@php script.php",
            "phpunit"
        ]
    }
}

One limitation of this is that you can not call multiple commands in a row like @php install && @php foo. You must split them up in a JSON array of commands.

You can also call a shell/bash script, which will have the path to the PHP executable available in it as a PHP_BINARY env var.

Controlling additional arguments#

As of Composer 2.8, you can control how additional arguments are passed to script commands.

When running scripts like composer script-name arg arg2 or composer script-name -- --option, Composer will by default append arg, arg2 and --option to the script's command.

If you do not want these args in a given command, you can put @no_additional_args anywhere in it, that will remove the default behavior and that flag will be removed as well before running the command.

If you want the args to be added somewhere else than at the very end, then you can put @additional_args to be able to choose exactly where they go.

For example running composer run-commands ARG with the below config:

{
    "scripts": {
        "run-commands": [
            "echo hello @no_additional_args",
            "command-with-args @additional_args && do-something-without-args --here"
        ]
    }
}

Would end up executing these commands:

echo hello
command-with-args ARG && do-something-without-args --here

Setting environment variables#

To set an environment variable in a cross-platform way, you can use @putenv:

{
    "scripts": {
        "install-phpstan": [
            "@putenv COMPOSER=phpstan-composer.json",
            "@composer install --prefer-dist"
        ]
    }
}

Custom descriptions#

You can set custom script descriptions with the following in your composer.json:

{
    "scripts-descriptions": {
        "test": "Run all tests!"
    }
}

The descriptions are used in composer list or composer run -l commands to describe what the scripts do when the command is run.

Note: You can only set custom descriptions of custom commands.

Custom aliases#

As of Composer 2.7, you can set custom script aliases with the following in your composer.json:

{
    "scripts-aliases": {
        "phpstan": ["stan", "analyze"]
    }
}

The aliases provide alternate command names.

Note: You can only set custom aliases of custom commands.

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