Error Identifier: generics.callSiteVarianceNotAllowed
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);
/** @template T */
interface Collection
{
}
/** @implements Collection<covariant string> */
class StringCollection implements Collection
{
}
Why is it reported? #
Call-site variance annotations (covariant and contravariant) are used in PHPDoc to project type parameters at use sites. However, they are not allowed when specifying type arguments in @extends, @implements, or @use tags. These locations require concrete type arguments, not variance-annotated projections.
In the example above, covariant string is used in the @implements tag, but call-site variance annotations are not meaningful in this context because the class is providing a concrete type for the template parameter.
How to fix it #
Remove the variance annotation and specify the type directly:
<?php declare(strict_types = 1);
-/** @implements Collection<covariant string> */
+/** @implements Collection<string> */
class StringCollection implements Collection
{
}
How to ignore this error #
You can use the identifier generics.callSiteVarianceNotAllowed to ignore this error using a comment:
// @phpstan-ignore generics.callSiteVarianceNotAllowed
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: generics.callSiteVarianceNotAllowed