16f6c0aecf
Inline adoc files when they are included exactly once. Also fix language tags because this inlining gives us better information on what language the code is written in.
79 lines
1.8 KiB
Plaintext
79 lines
1.8 KiB
Plaintext
== Why is this an issue?
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The ``++in++`` operator used on an array is valid but the code will likely not have the expected behavior. The ``++in++`` operator deals with the indexes of the array, not with the values.
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If checking for an array slot is indeed desired, using ``++hasOwnProperty++`` makes the code intention clearer.
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=== Noncompliant code example
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[source,javascript]
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----
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function func1() {
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let arr = ["a", "b", "c"];
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let expectedValue = "b";
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if (expectedValue in arr) { // Noncompliant, will be always false
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return expectedValue + " found in the array";
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} else {
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return expectedValue + " not found";
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}
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}
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function func2() {
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let arr = ["a", "b", "c"];
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let expectedValue = "1"; // index #1 is corresponding to the value "b"
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if (expectedValue in arr) { // Noncompliant, will be always true because the array is made of 3 elements and the #1 is always there whatever its value
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return expectedValue + " found in the array";
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} else {
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return expectedValue + " not found";
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}
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}
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----
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=== Compliant solution
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[source,javascript]
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----
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function func() {
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let arr = ["a", "b", "c"];
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let expectedValue = "b";
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if (arr.includes(expectedValue)) {
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return expectedValue + " was found in the array";
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} else {
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return expectedValue + " not found";
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}
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}
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----
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Use "indexOf" or "includes" (available from ES2016) instead.
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=== Highlighting
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"in" expression
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'''
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== Comments And Links
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(visible only on this page)
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=== on 7 May 2018, 13:56:14 Stas Vilchik wrote:
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\[~alexandre.gigleux] JavaScript is not a compiled language, so please remove the word "compile" from the description.
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endif::env-github,rspecator-view[]
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