The typehint provided for the function is not a valid class type. This may happen because of a typo, or the class specified in typehint is not present in the current namespace. You can also face this issue on using native union types if your PHP version is < 8.0. Native union types are only available in PHP 8.0 and later.

Bad Practice

// invalid: User class used as return type doesn't exists
function getUser(): User
{
    return new User('John');
}

class User
{
    public function update(array $data) {}
}

// invalid: Parameter type contains typo
function updateUser(Usr $user, array $data): void
{
    $user->update(['name' => $data['name']]);
}

Recommended

Make sure class used in return typehint exists:

class User
{
    private string $name;

    public function __construct(string $name)
    {
        $this->name = $name;
    }
}

function getUser(): User
{
    return new User('John');
}

Make sure there are no typos:

class User
{
    public function update(array $data) {}
}

// invalid: Parameter type contains typo
function updateUser(User $user, array $data): void
{
    $user->update(['name' => $data['name']]);
}

References

Type declarations

rafandoo / HelpDeskRplus

No ignore rules found