#switch-exhaustiveness-check

#Configuration

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/switch-exhaustiveness-check': 'error',
    },
  },
]);

#Rule Details

Require switch statements over union types to be exhaustive. When switching over a union type (such as a discriminated union or enum), it is easy to forget to handle all possible cases. This rule ensures that every possible value of the union is handled with a case clause, either explicitly or via a default clause, preventing runtime errors from unhandled values.

Examples of incorrect code for this rule:

type Direction = 'north' | 'south' | 'east' | 'west';

function move(dir: Direction) {
  switch (dir) {
    case 'north':
      break;
    case 'south':
      break;
    // 'east' and 'west' are not handled
  }
}

Examples of correct code for this rule:

type Direction = 'north' | 'south' | 'east' | 'west';

function move(dir: Direction) {
  switch (dir) {
    case 'north':
      break;
    case 'south':
      break;
    case 'east':
      break;
    case 'west':
      break;
  }
}

#Original Documentation

• typescript-eslint switch-exhaustiveness-check