The return type of return false; (false) is incompatible with the return type documented by NoXMLSpace::noSpace of type xml.
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
for object oriented design.
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.
This code seems to be duplicated across your project.
Duplicated code is one of the most pungent code smells. If you need to duplicate
the same code in three or more different places, we strongly encourage you to
look into extracting the code into a single class or operation.
You can also find more detailed suggestions in the “Code” section of your repository.