rspec/rules/S2692/javascript/rule.adoc

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

----
var color = "blue";
var name = "ishmael";

var arr = [color, name];

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

== Compliant Solution

----
var color = "blue";
var name = "ishmael";

var arr = [color, name];

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

== See

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