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Error Identifier: mixin.deprecatedClass

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);

/** @deprecated Use NewHelper instead */
class OldHelper
{
	public function help(): void {}
}

/**
 * @mixin OldHelper
 */
class Foo // ERROR: PHPDoc tag @mixin references deprecated class OldHelper.
{
}

Why is it reported? #

This error is reported by phpstan/phpstan-deprecation-rules.

The @mixin PHPDoc tag references a class that has been marked as deprecated with the @deprecated PHPDoc tag. Using deprecated classes should be avoided because they may be removed in a future version of the library or application. The deprecation notice typically suggests a replacement class to use instead.

How to fix it #

Replace the deprecated class with its suggested replacement:

 <?php declare(strict_types = 1);
 
 /**
- * @mixin OldHelper
+ * @mixin NewHelper
  */
 class Foo
 {
 }

If no direct replacement exists, remove the @mixin tag and implement the needed methods directly:

 <?php declare(strict_types = 1);
 
-/**
- * @mixin OldHelper
- */
 class Foo
 {
+	public function help(): void {}
 }

How to ignore this error #

You can use the identifier mixin.deprecatedClass to ignore this error using a comment:

// @phpstan-ignore mixin.deprecatedClass
codeThatProducesTheError();

You can also use only the identifier key to ignore all errors of the same type in your configuration file in the ignoreErrors parameter:

parameters:
	ignoreErrors:
		-
			identifier: mixin.deprecatedClass

Rules that report this error #

  • PHPStan\Rules\Deprecations\RestrictedDeprecatedClassNameUsageExtension [1] phpstan/phpstan-deprecation-rules

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