Error Identifier: property.virtualDefault

Every error reported by PHPStan has an error identifier. Here’s a list of all error identifiers. In PHPStan Pro you can see the error identifier next to each error and filter errors by their identifiers.

Code example #

<?php declare(strict_types = 1);

class User
{
	public string $fullName = 'Unknown' {
		get => $this->firstName . ' ' . $this->lastName;
	}

	public string $firstName = 'John';
	public string $lastName = 'Doe';
}

Why is it reported? #

A virtual hooked property has no backing storage – it computes its value through hooks. Assigning a default value to such a property is not allowed because there is no field to store it. PHP rejects this at compile time.

A property is virtual when all of its hooks are defined and none of them reference $this->propertyName for the property itself.

How to fix it #

Remove the default value from the virtual property:

-public string $fullName = 'Unknown' {
+public string $fullName {
 	get => $this->firstName . ' ' . $this->lastName;
 }

Or add a backing store by including a set hook that assigns to $this->fullName:

 public string $fullName = 'Unknown' {
 	get => $this->firstName . ' ' . $this->lastName;
+	set => $this->fullName = $value;
 }

Non-ignorable error #

This error cannot be ignored using @phpstan-ignore or the ignoreErrors configuration. Non-ignorable errors indicate code that would cause a crash or a fatal error at runtime, or a fundamental problem in the analysed code that must be addressed.

Rules that report this error #

PHPStan\Rules\Properties\PropertyInClassRule [1]

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