rspec/rules/S3760/javascript/rule.adoc

== Why is this an issue?

Expressions with arithmetic (``/, {empty}*, %, {plus}{plus}, --, -, -=, {empty}*=, /=, %=, +=, {plus}``), unary (``++-++``), or comparison operators (``++>, <, >=, <=++``) where one, or both, of the operands is a String, Boolean or Date value rely on implicit conversions. Both the maintainability and reliability levels of such a piece of code are questionable.


=== Noncompliant code example

[source,javascript]
----
str = "80";
quarter = str / 4; // Noncompliant

if (str < 10) { // Noncompliant
   // ...
}
----


=== Compliant solution

[source,javascript]
----
str = "80";
parsedStr = parseInt(str);
quarter = parsedStr / 4;

if (parsedStr < 10) {
  // ...
}
----


=== Exceptions

* Expressions using the binary ``{plus}`` operator with at least one ``++String++`` operand are ignored because the ``{plus}`` operator will perform a concatenation in that case.
* Comparisons where both operands are strings are ignored because a lexicographical comparison is performed in that case.


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

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

=== Message

Convert this operand into a number.


=== Highlighting

Primary: non numerical operand


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

=== on 18 Oct 2016, 10:59:01 Pierre-Yves Nicolas wrote:
The current title of the rule seems rather vague to me. Shouldn't it mention "arithmetic and comparison expressions"?

=== on 18 Oct 2016, 13:09:38 Ann Campbell wrote:
\[~jeanchristophe.collet], please reword title into canonical form (x should [not] y)

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