rspec/rules/S2159/python/rule.adoc

== Why is this an issue?

In some cases a comparison with operators ``++==++``, or ``++!=++`` will always return True or always return False. When this happens, the comparison and all its dependent code can simply be removed. This includes:

* comparing unrelated builtin types such as string and integer.
* comparing class instances which do not implement ``++__eq__++`` or ``++__ne__++`` to an object of a different type (builtin or from an unrelated class which also doesn't implement ``++__eq__++`` or ``++__ne__++``).

=== Noncompliant code example

[source,python]
----
foo = 1 == "1"  # Noncompliant. Always False.

foo = 1 != "1"  # Noncompliant. Always True.

class A:
    pass

myvar = A() == 1  # Noncompliant. Always False.
myvar = A() != 1  # Noncompliant. Always True.
----

=== Compliant solution

[source,python]
----
foo = 1 == int("1")

foo = str(1) != "1"

class Eq:
    def __eq__(self, other):
        return True

myvar = Eq() == 1
myvar = 1 == Eq()
myvar = Eq() != 1  # Ok. "__ne__" calls "__eq__" by default
myvar = 1 != Eq()
----

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

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

=== Message

* Remove this equality check between incompatible types X and Y; it will always return True/False


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

include::../comments-and-links.adoc[]

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