no-confusing-void-expression.md

Pattern: Misplaced void expression in value position

Issue: -

Description

A void expression represents a function call meant to be ignored, but using it in a value position (like assignment or return) creates confusing code. This can lead to programmer errors when void values are accidentally used where actual values are expected.

Examples

Example of incorrect code:

// Storing void result in variable
const result = alert('Warning');

// Using void result in console
console.log(alert('Hello'));

// Returning void result
function logError() {
  return console.error('Failed');
}

// Chaining void promise
promise.then(value => window.postMessage(value));

Example of correct code:

// Void function in statement position
alert('Warning');

// Explicit void handling in promise
promise.then(value => {
  window.postMessage(value);
});

// Explicit return after void call
function logError() {
  console.error('Failed');
  return;
}

// Side effects in logical expressions
condition && console.log('True');
condition ? console.log('Yes') : console.log('No');

// Using void operator when intended
return void console.log('Done');