sync-generator-promises.js

function resolvePromise(promise, iterator) {
    promise.then(
        (response) => {
            let result = iterator.next(response);
            if (!result.done) {
                sync(result.value, iterator);
            }
        },
        error => {
            let result = iterator.next(error);
            if (!result.done) {
                sync(result.value, iterator);
            }
        }
    );
}

function resolveGenerator(generator, iterator) {
    let result = generator.next();


    if (!result.done) {
        sync(result.value, iterator);
    }
}

function resolveSimpleResult(result, iterator) {
    let _result = iterator.next(result);
    if (!_result.done) {
        sync(_result.value, iterator)
    }
}

function callGenerator(generator) {
    if (typeof generator == "function") {
        return generator();
    }

    return generator;
}

function decideOnGeneratorOrPromiseOrSimpleAnswer(result) {
    if (result.next) {
        return {type: "generator", result};
    } else if (result.then) {
        return {type: "promise", result};
    }

    return {type: "result", result};
}

function chooseGenerator(generator, iterator) {
    if (generator.next) {
        return generator;
    }

    return iterator;
}

export function sync(generator, iterator) {
    let {type, result} = decideOnGeneratorOrPromiseOrSimpleAnswer(callGenerator(generator));
    if (type == "generator") {
        resolveGenerator(result, chooseGenerator(result, iterator));
    } else if (type == "promise") {
        resolvePromise(result, chooseGenerator(result, iterator));
    } else if (type == "result") {
        console.log(result);
        resolveSimpleResult(result, chooseGenerator(result, iterator));
    }
}



/////////////////////////////////////////
// utitlities and foo bar example
///////////////////////////////////////

// throwError
export function throwError(middleWareName, recover, _message = "") {
	let error = new Error('cant pass ' + middleWareName);
	error.recover = function () {
		recover();
	};

	error.message = function () {
		return _message;
	};

	throw  error;
}

//isLoginMiddleWare
export function* isLoginMiddleware(nextState, replace, next) {
	let {user, response} = yield ping();

	if (response.statusCode == 200) {
		throwError('isLoginMiddleware', function () {
			console.log('recovered')
		}, 'custom message');
		replace('/profile');
	} else {
		browserHistory.push('/login');
		AlertBox("error", "لطفا در ابتدا وارد حساب کاربری شوید")
	}
}

// example
sync(function*() {
	try {
		yield* isLoginMiddleware(nextState, replace);

		next()
	} catch (error) {
		error.recover();
		console.log(error.message())
	}
});