1
0
mirror of https://github.com/danog/psalm.git synced 2024-12-05 21:19:03 +01:00
psalm/docs/running_psalm/issues/ParamNameMismatch.md

96 lines
2.3 KiB
Markdown
Raw Normal View History

# ParamNameMismatch
Emitted when method overrides a parent method but renames a param.
```php
<?php
class A {
public function foo(string $str, bool $b = false) : void {}
}
class AChild extends A {
public function foo(string $string, bool $b = false) : void {}
}
```
## Why is this bad?
PHP 8 introduces [named parameters](https://wiki.php.net/rfc/named_params) which allow developers to call methods with explicitly-named parameters;
```php
<?php
function callFoo(A $a) {
$a->foo(str: "hello");
}
```
In the first example passing `new AChild()` to `callFoo()` results in a fatal error, as AChild's definition of the method `foo()` doesn't have a parameter named `$str`.
## How to fix
You can change the child method param name to match:
```php
<?php
class A {
public function foo(string $str, bool $b = false) : void {}
}
class AChild extends A {
public function foo(string $str, bool $b = false) : void {}
}
```
2020-08-17 17:58:30 +02:00
This fix [can be applied automatically by Psalter](https://psalm.dev/docs/manipulating_code/fixing/#paramnamemismatch).
## Workarounds
2020-08-14 06:27:33 +02:00
### @no-named-arguments
2020-08-14 06:27:33 +02:00
Alternatively you can ignore this issue by adding a `@no-named-arguments` annotation to the parent method:
```php
<?php
class A {
/** @no-named-arguments */
public function foo(string $str, bool $b = false) : void {}
}
class AChild extends A {
public function foo(string $string, bool $b = false) : void {}
}
```
Any method with this annotation will be prevented (by Psalm) from being called with named parameters, so the original issue does not matter.
2020-08-14 06:27:33 +02:00
### Config allowNamedArgumentCalls="false"
This prevents any use of named params in your codebase. Ideal for self-contained projects, but less ideal for libraries.
It means the original code above will not emit any errors as long as the class `A` is defined in a directory that Psalm can scan.
2020-08-14 06:27:33 +02:00
### Config allowInternalNamedArgumentCalls="false"
For library authors Psalm supports a more nuanced flag that tells Psalm to prohibit any named parameter calls on `@internal` classes or methods.
With that config value, this is now allowed:
```php
<?php
/**
* @internal
*/
class A {
public function foo(string $str, bool $b = false) : void {}
}
class AChild extends A {
public function foo(string $string, bool $b = false) : void {}
}
```