CodeQL documentation

Non-case label in switch statement

ID: js/label-in-switch Kind: problem Security severity: Severity: warning Precision: very-high Tags: - quality - reliability - correctness Query suites: - javascript-code-quality.qls - javascript-security-and-quality.qls 

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JavaScript allows to freely mix case labels and ordinary statement labels in the body of a switch statement. However, this is confusing to read (especially if both kinds of labels have the same amount of indentation), and indeed most likely the result of a typo.

Recommendation

Examine the statement labels to see whether they were meant to be case labels. If not, consider wrapping them into a statement block and indent them to set them apart visually from the case labels.

Example

In this example, the label case3 is most likely a typo for case 3 and should be fixed.

function f(x) { switch (x) { case 1: case 2: case3: return true; default: return false; } } 

References

  • Ecma International, ECMAScript Language Definition, 5.1 Edition, Section 12.11. ECMA, 2011.