JSFiddle - React, Tailwind, and code Playground

JavaScript

function Executor(program, args, errorAction) {
	this.program = program;
	this.args = args;	
	
	this.successAction = function(data) {
		console.log(data);
	};

	this.errorAction = function(err) {
		console.log(err);
	};
	
	this.execute = function() {
		var argsString = "";
		for(var o in args) {
			argsString += args[o] + ' ';
		}
		var command = this.program + ' ' + argsString;
		console.log("Execution => " + command);
    this.errorAction("йоба");	//                      тут выполняется
		exec(command, function(err, data) {
			if(err != null) {
				this.errorAction(err);		//                  а тут нет :(
			} else {
				this.successAction(data);
			}
		});
	}
	this.execute();
}