test-railway.js

test-railway.js

const addOne = value => {
	return value + 1;
};

const failIfOdd = value => {
	return value + 1;
};

function railway ( chain ) {
	return new Promise((resolve) => {
		chain( val => new Promise( resolve => resolve( val ) ) )
			.then( result => resolve( [ true, result ] ) )
			.catch( error => resolve( [ false, error ] ) );
	});
}	

const [ ok, result ] = railway(
	start => {
		start( 1 )
		.then( addOne )
		.then( failIfOdd )
		.then( addOne )
	}
);

console.log(ok, result);