Error Identifier: callable.shadowTemplate
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
*/
class Collection
{
/**
* @param callable<T>(T): T $callback
*/
public function map(callable $callback): void
{
}
}
Why is it reported? #
A generic callable type in a PHPDoc tag defines a template type parameter with the same name as an existing template on the enclosing function or class. In the example above, both the class and the map method define a template named T, which creates ambiguity about which T is being referred to inside the callable type.
How to fix it #
Rename the template type parameter in the callable to avoid shadowing:
<?php declare(strict_types = 1);
/**
* @template T
*/
class Collection
{
/**
- * @param callable<T>(T): T $callback
+ * @param callable<U>(U): U $callback
*/
public function map(callable $callback): void
{
}
}
How to ignore this error #
You can use the identifier callable.shadowTemplate to ignore this error using a comment:
// @phpstan-ignore callable.shadowTemplate
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: callable.shadowTemplate