rspec/rules/S3043/java/rule.adoc

== Why is this an issue?

Perhaps counter-intuitively, a ``++compareTo++`` method is _expected_ to throw a ``++NullPointerException++`` if passed a null argument, and a ``++ClassCastException++`` if the argument is of the wrong type. So there's no need to null-test or type-test the argument.


=== Noncompliant code example

[source,java]
----
public int compareTo(Object obj) {

  if (obj == null) { // Noncompliant
    return -1;
  }
  if (! obj instanceof MyClass.class) { // Noncompliant
    return -1;
  }

  MyObject myObj = (MyObject) obj;
  // ...
}
----


=== Compliant solution

[source,java]
----
public int compareTo(Object obj) {

  MyObject myObj = (MyObject) obj;
  // ...
}
----



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

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

=== Message

* Remove this null-test of "xxx".
* Remove this type-test of "xxx".


'''
== Comments And Links
(visible only on this page)

=== on 11 Jun 2015, 18:11:17 Ann Campbell wrote:
CodePro: Allow compareTo to Throw Exceptions

=== on 16 Jun 2015, 13:14:22 Nicolas Peru wrote:
Not an easy one, but looks good.

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