The `prefer-switch` rule can behave strangely in certain situations

Description

  // eslint-disable-next-line unicorn/prefer-switch
  if (typeof document.exitFullscreen === 'function') {
    await document.exitFullscreen();
  } else if (typeof document.webkitExitFullscreen === 'function') {
    await document.webkitExitFullscreen();
  } else if (typeof document.mozExitFullscreen === 'function') {
    await document.mozExitFullscreen();
  }

  switch ('function') {
    case typeof document.exitFullscreen: {
      await document.exitFullscreen();

      break;
    }
    case typeof document.webkitExitFullscreen: {
      await document.webkitExitFullscreen();

      break;
    }
    case typeof document.mozExitFullscreen: {
      await document.mozExitFullscreen();

      break;
    }
  // No default
  }

Contributor guide

Tech stack

javascripttypescript

Domain

toolingdeveloper experience

Issue type

bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

1-3 hours

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

fresh

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

understanding of ESLint rule creationJavaScriptTypeScriptAST basics

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

45

Research direction

Look at the implementation of the `prefer switch` rule, likely in `rules/prefer switch.js`. The bug occurs when the `if` condition is a `typeof` comparison against a string literal. The rule incorrectly transforms these into a switch on the string value. Investigate how the rule detects if statements suitable for conversion and add a check to exclude `typeof` comparisons.