Identifying Typescript argument types

The given code is functional, but I am looking to refactor it for better clarity using Typescript syntax if possible.

class Actions { actions: string[] }
type Argument = object | Actions;

export class GetFilesContext implements IExecutable {

   execute( args: Argument, response: ServerResponse<IncomingMessage> ): void {
      ...
      // eslint-disable-next-line no-prototype-builtins
      if( args && args.hasOwnProperty( "actions" )) {
         ctxt.actions.length = 0;
         ctxt.actions.push( ...(args as Actions).actions );
      }
      response.end( JSON.stringify( ctxt ));
   }
}

The conditional check:

// eslint-disable-next-line no-prototype-builtins
if( args && args.hasOwnProperty( "actions" )) {

translates to "if args is defined and contains an attribute called actions"

How can this be rewritten?

I attempted to use typeof and instanceof, but without success.

typescriptvariable-types

Answer №1

The solution to this problem was provided by pink in the comments section. Much appreciated!

type Argument = object | { actions: string[] };

export class GetFilesContext implements IExecutable {

   execute( args: Argument, response: ServerResponse<IncomingMessage> ): void {
      ...
      if( args &&( 'actions' in args )) {
         ctxt.actions.push( ...args.actions );
      }
      response.end( JSON.stringify( ctxt ));
   }
}

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