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noUnusedLabels (since v1.0.0)

Diagnostic Category: lint/correctness/noUnusedLabels

Source: no-unused-labels

Disallow unused labels.

Labels that are declared and never used are most likely an error due to incomplete refactoring.

Examples

Section titled Examples

Invalid

Section titled Invalid
LOOP: for (const x of xs) {
    if (x > 0) {
        break;
    }
    f(x);
}
correctness/noUnusedLabels.js:1:1 lint/correctness/noUnusedLabels  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Unused label.
  
  > 1 │ LOOP: for (const x of xs) {
      │ ^^^^
    2 │     if (x > 0) {
    3 │         break;
  
  ℹ The label is not used by any break statement and continue statement.
  
  ℹ Safe fix: Remove the unused label.
  
    1 │ LOOP:·for·(const·x·of·xs)·{
      │ ------

Valid

Section titled Valid
LOOP: for (const x of xs) {
    if (x > 0) {
        break LOOP;
    }
    f(x);
}
function nonNegative(n) {
    DEV: assert(n >= 0);
    return n;
}
Section titled Related links