How do you get the package name from a Composer event? - composer-php

Question

The Problem
I'm attempting to set up a post-update script with Composer that checks to see which package is being updated. However, I'm having trouble figuring out how to consistently get the package name from a Composer\Installer\PackageEvent.
Attempts to solve
The source code says that $packageEvent->getOperation->getReason() should return a string, but in my testing is actually returning an instance of Composer\DependencyResolver\GenericRule.
Calling Composer\DependencyResolver\Rule::getReasonData() sometimes returns a string (the package name), and sometimes returns Composer\Package\Link.
The following code mostly works to figure out the package's name:
$reasonData = $packageEvent->getOperation()->getReason()->getReasonData();
$packageName = is_string($reasonData) ? $reasonData : $reasonData->getTarget();
except sometimes $packageEvent->getOperation()->getReason() returns null.
The Question
How do you consistently get the package name from a Composer PackageEvent?
Bonus Points
How do you get the name of the package being installed/updated/etc. from all of the Composer event classes?

Answer 1

My mistake! Composer operations still have access to packages, just through different methods, which depend on whether the operation is an InstallOperation or an UpdateOperation. The following works:
/**
* Returns the package name associated with $event
*
* #param PackageEvent $event Package event
* #return string
*/
public static function getPackageName(PackageEvent $event)
{
/** #var InstallOperation|UpdateOperation $operation */
$operation = $event->getOperation();
$package = method_exists($operation, 'getPackage')
? $operation->getPackage()
: $operation->getInitialPackage();
return $package->getName();
}