Javascript === ‘mint!’

Consider this rather lengthy approach to error checking:

if (errors.length > 0) {
  next(errors);
} else {
  next();
}

Typically, you would use a ternary operator to express this more tersely:

next(errors.length > 0 ? errors : null);

However, this often becomes ugly and cumbersome with symbols littering themselves thought the code, for example:

next(errors.length > 0 ? errors.length < 10 ? errors : null);

My prefered approach is as follows:

next(errors.length && errors || null);

This uses short-circuit evaluation to return null if there are zero errors and implicit conversion to return the errors if there are any.