Unreachable 'case' branch of a 'switch' statement

Reports an unreachable case branch of a switch statement.

Example:

/**
 * @param {('foo' | 'bar')} p
 */
function foo(p) {
    switch (p) {
        case 'foo': break;
        case 'bar': break;
        case 'baz': break; // unreachable
    }
}

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

JSUnreachableSwitchBranches

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | JavaScript and TypeScript | Switch statement issues

Inspection options

Here you can find the description of settings available for the Unreachable 'case' branch of a 'switch' statement inspection, and the reference of their default values.

Don't show this warning in the context of a dynamic type: Default: Selected

Inspection Details
By default bundled with:	CLion 2025.1, GoLand 2025.1, IntelliJ IDEA 2024.3, JetBrains Rider 2024.3, PhpStorm 2024.3, PyCharm 2025.1, Qodana for .NET 2024.3, Qodana for Go 2025.1, Qodana for JS 2025.1, Qodana for JVM 2024.3, Qodana for PHP 2024.3, Qodana for Ruby 2025.1, RubyMine 2025.1, WebStorm 2025.1
Can be installed with plugin:	JavaScript and TypeScript, 251.24737

01 April 2025