Faux Implementation of Redux-Saga

saga-implementation-example.js

/*
The following is a fake implementation of functions inside of Redux-Saga.
*/

// Simplistic fake implementations of Saga Effects
const put = action => ({effect:'PUT', action});
const call = fn => ({effect:'CALL', fn});

// Simplistic fake implementation of runSaga
function runSaga(genFn, ...args){
  const gen = genFn(...args);
  let next = gen.next();
  while(!next.done){
    const {effect, action, fn} = next.value;
    switch(effect){
      case 'PUT':
        dispatch(action);
        next = gen.next(action);
        break;
      case 'CALL':
        next = gen.next(fn());
        break;
    }
  }
}

// Fake Redux dispatch
function dispatch(action){
  console.log(`Dispatching ${JSON.stringify(action)}`); 
}

/*
The rest of the code in this gist is code that you would supply to make use of the Redux-Saga functions above
*/
// Make a saga
function* mySaga(value){
  yield put({type:'FIRST_ACTION', value});
  const active = yield call(isActive);
  if(active){
    yield put({type:'ACTIVE_ACTION'});
  }else{
    yield put({type:'WONT_BE_DISPATCHED'}); 
  }
}

// helper for demonstration purposes
function isActive(){
  return true;
}

// Run the saga!
runSaga(mySaga, 123);

/*
Running this code will output:
Dispatching {"type":"FIRST_ACTION","value":123}
Dispatching {"type":"ACTIVE_ACTION"}
*/