rspec/rules/S4351/java/rule.adoc

== Why is this an issue?

When implementing the ``++Comparable<T>.compareTo++`` method, the parameter's type has to match the type used in the ``++Comparable++`` declaration. When a different type is used this creates an overload instead of an override, which is unlikely to be the intent.


This rule raises an issue when the parameter of the ``++compareTo++`` method of a class implementing ``++Comparable<T>++`` is not same as the one used in the ``++Comparable++`` declaration.


=== Noncompliant code example

[source,java]
----
public class Foo {
  static class Bar implements Comparable<Bar> {
    public int compareTo(Bar rhs) {
      return -1;
    }
  }

  static class FooBar extends Bar {
    public int compareTo(FooBar rhs) {  // Noncompliant: Parameter should be of type Bar
      return 0;
    }
  }
}
----


=== Compliant solution

[source,java]
----
public class Foo {
  static class Bar implements Comparable<Bar> {
    public int compareTo(Bar rhs) {
      return -1;
    }
  }

  static class FooBar extends Bar {
    public int compareTo(Bar rhs) {
      return 0;
    }
  }
}
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Refactor this method so that its argument is of type 'xxx'


=== Highlighting

compareTo declaration


endif::env-github,rspecator-view[]