src/content/docs/linter/rules/no-duplicate-case.mdx
import { Tabs, TabItem } from '@astrojs/starlight/components';
<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v1.0.0` - Diagnostic Category: [`lint/suspicious/noDuplicateCase`](/reference/diagnostics#diagnostic-category) - This rule is **recommended**, meaning it is enabled by default. - This rule doesn't have a fix. - The default severity of this rule is [**error**](/reference/diagnostics#error). - Sources: - Same as [`no-duplicate-case`](https://eslint.org/docs/latest/rules/no-duplicate-case){
"linter": {
"rules": {
"suspicious": {
"noDuplicateCase": "error"
}
}
}
}
Disallow duplicate case labels.
If a switch statement has duplicate test expressions in case clauses, it is likely that a programmer copied a case clause but forgot to change the test expression.
switch (a) {
case 1:
break;
case 1:
break;
default:
break;
}
switch (a) {
case one:
break;
case one:
break;
default:
break;
}
switch (a) {
case "1":
break;
case "1":
break;
default:
break;
}
switch (a) {
case 1:
break;
case 2:
break;
default:
break;
}
switch (a) {
case one:
break;
case two:
break;
default:
break;
}
switch (a) {
case "1":
break;
case "2":
break;
default:
break;
}