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SubCommand::setupSubCommands()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 4
Code Lines 2

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
dl 0
loc 4
rs 10
c 0
b 0
f 0
cc 1
eloc 2
nc 1
nop 0
1
<?php namespace Tarsana\Command;
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use Tarsana\Command\Command;
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/**
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 * A SubCommand which has a parent command and can access it.
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 */
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abstract class SubCommand extends Command {
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    /**
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     * The parent command.
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     *
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     * @var Tarsana\Command\Command
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     */
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    protected $parent;
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    /**
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     * Creates a new SubCommand.
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     *
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     * @param Command $parent
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     */
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    public function __construct(Command $parent)
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    {
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        parent::__construct();
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        $this->parent = $parent;
0 ignored issues
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Documentation Bug introduced by
It seems like $parent of type object<Tarsana\Command\Command> is incompatible with the declared type object<Tarsana\Command\Tarsana\Command\Command> of property $parent.

Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property.

Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property..

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        $this->console = $parent->console;
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    }
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    protected function setupSubCommands()
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    {
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        return $this;
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    }
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    /**
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     * parent getter and setter.
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     *
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     * @param  Tarsana\Command\Command|null
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     * @return Tarsana\Command\Command
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     */
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    public function parent(Command $value = null)
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    {
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        if (null === $value) {
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            return $this->parent;
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        }
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        $this->parent = $value;
0 ignored issues
show
Documentation Bug introduced by
It seems like $value of type object<Tarsana\Command\Command> is incompatible with the declared type object<Tarsana\Command\Tarsana\Command\Command> of property $parent.

Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property.

Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property..

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        return $this;
0 ignored issues
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Bug Best Practice introduced by
The return type of return $this; (Tarsana\Command\SubCommand) is incompatible with the return type documented by Tarsana\Command\SubCommand::parent of type Tarsana\Command\Tarsana\Command\Command.

If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.

Let’s take a look at an example:

class Author {
    private $name;

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

    public function getName() {
        return $this->name;
    }
}

abstract class Post {
    public function getAuthor() {
        return 'Johannes';
    }
}

class BlogPost extends Post {
    public function getAuthor() {
        return new Author('Johannes');
    }
}

class ForumPost extends Post { /* ... */ }

function my_function(Post $post) {
    echo strtoupper($post->getAuthor());
}

Our function my_function expects a Post object, and outputs the author of the post. The base class Post returns a simple string and outputting a simple string will work just fine. However, the child class BlogPost which is a sub-type of Post instead decided to return an object, and is therefore violating the SOLID principles. If a BlogPost were passed to my_function, PHP would not complain, but ultimately fail when executing the strtoupper call in its body.

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    }
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}
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