no-unused-vars-error.js

/**
 * Proposing a new rule for no-unused-vars.args
 * See http://eslint.org/docs/rules/no-unused-vars#args
 * It would behave similar to after-used, except arguments with `error` sounding names should cause errors if ignored
 * Configuring this manually with an array would be great
 */

/*eslint no-unused-vars: ["error", { "args": "after-used-and-errors", "errors": ["e", "err", "error"] }]*/

asyncWork((err, data) => { // e.g. args: all
  // In this case I want eslint to error as I'm not handling my error
  data.xyz = true;
  callback(null, data);
});

asyncWork((err, ignorable, data) => {
  // Ignoring `ignorable` should be okay
  if (err) {
    return callback(err);
  }
  
  data.xyz = true;

  callback(null, data);
});

function somethingSync(ignorable, realData) { // e.g. args: after-used
  // Here I don't want eslint to error, I need to ignore `ignorable` to get to realData
  return realData++;
}

eslint/eslint#9112