docs: remove useless @return BaseConnection|ConnectionInterface on BaseBuilder::db()

[samsonasik]

Description

BaseConnection is implements ConnectionInterface so it can be removed from @return doc. Detected by run latest "rector/rector": "dev-main"

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[samsonasik]

Ready to merge 👍

[kenjis]

BaseConnection is implements ConnectionInterface so it can be removed from @return doc.

Why? BaseConnection has more public methods than ConnectionInterface.

In fact, the db() returns BaseConnection.
Or the return type ConnectionInterface is incorrect.

Or ConnectionInterface is broken.
Or we don't know how to use interface correctly.
See #4356

[samsonasik]

The problem with including the interface itself in the union make all other type already valid as child of it.

The current usage is incorrect imo, if union type to be used, both should be a class that implement the interface, eg, for param which valid:

/** @param SomeClass|SomeClass2 $param */
public function run(SomeInterface $param)
{
   echo $param->prop;
}

which both SomeClass and SomeClass2 child of SomeInterface and has prop property, so that "more" data is valid.

[samsonasik]

The another solution is mark as BaseConnection instead:

/** @return BaseConnection */
public function db(): ConnectionInterface

[samsonasik]

@kenjis I updated to @return BaseConnection a2802a6

[kenjis]

@samsonasik Yes, after all, our code is incorrect.
But I think this is better.

/** @return BaseConnection */
public function db(): ConnectionInterface

Because devs expect BaseConnection instead of ConnectionInterface.

[samsonasik]

done 👍

[samsonasik]

Thank you @kenjis for the review.