rspec/rules/S2692/javascript/rule.adoc

== Why is this an issue?

Most checks against an ``++indexOf++`` call against an array compare it with -1 because 0 is a valid index. Any checks which look for values >0 ignore the first element, which is likely a bug. If you're merely checking the presence of the element, consider using ``++includes++`` instead. Before using ``++includes++`` method make sure that your browser version is supporting it.

=== Noncompliant code example

[source,javascript]
----
var color = "blue";
var name = "ishmael";

var arr = [color, name];

if (arr.indexOf("blue") > 0) { // Noncompliant
  // ...
}
----

=== Compliant solution

[source,javascript]
----
var color = "blue";
var name = "ishmael";

var arr = [color, name];

if (arr.indexOf("blue") >= 0) { 
  // ...
}
if (arr.includes("blue")) { 
  // ...
}
----

== Resources

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes[Array.prototype.includes()] documentation at MDN

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

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

=== Message

This check ignores index 0; consider using 'includes' method to make this check safe and explicit.


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

=== on 10 Apr 2017, 15:29:04 Elena Vilchik wrote:
Temporary removed from SW before FP are removed: SONARJS-991

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

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