classConstant.inTrait

Code example

<?php declare(strict_types = 1);

trait FooBar
{
	const FOO = 'foo';
	public const BAR = 'bar';
}

class Consumer
{
	use FooBar;
}

Why is it reported?

Constants in traits are only supported starting from PHP 8.2. If the project targets an earlier PHP version, declaring a constant inside a trait will cause a syntax error at runtime. This error is reported when PHPStan detects that the configured PHP version is lower than 8.2.

How to fix it

Move the constants to the class that uses the trait, or to an interface:

 <?php declare(strict_types = 1);

 trait FooBar
 {
-	const FOO = 'foo';
-	public const BAR = 'bar';
 }

 class Consumer
 {
 	use FooBar;
+
+	const FOO = 'foo';
+	public const BAR = 'bar';
 }

Or upgrade the minimum PHP version of the project to 8.2 or later.