Missing native return type declaration for closure/anonymous function PHP-T1003
Type check
Minor
The closure/anonymous function is missing the native return type declaration. Native return type can help enforce type, which can lead to more readable, reliable code. They ensure that the value is of the specified type at call time, otherwise a TypeError is thrown.
Use of nullable mixed is forbidden PHP-T1006
Type check
Critical
Autofix
The mixed type already includes null, so specifying mixed type as a nullable is redundant and doesn't make any sense. PHP lets you typehint properties, parameters, and return values as mixed which can contain any value.
To fix this issue, it is recommended to drop null from the nullable mixed type.