beknar.askarov askbeka

## optional-spreading-explainer.md

      
        
          
            
              
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                askbeka
                / optional-spreading-explainer.md
            
            
              Last active
              October 22, 2020 10:19
            
              
                [es-proposal] Optional spreading. https://es.discourse.group/t/optional-spreading-proposal/224
              
          
        
      
        
  
      
    TLDR;

Optional spreading [?...ArrayOrNullish] {?...ObjectOrNullish}. Noop when spreading value is nullish. Intuitive addition to javascript, inspired by optional chaining and Nullish coalescing operator
Problem

Spreading is great, it contributes towards "declerativity" of the language and reduces verbosity, but in case value being spread is nullish, we either have to give up on this feature or sacrifice verbosity and performance for declarativity.
Consider following code pattern that naturally appears in configuartion management
function getConfig(customConfig) {
 return {