src/main/scheduler/preprocess/manyDrawObjects.js

import moduleKeys from './../moduleKeys';

const { BIND, RENDER } = moduleKeys();

const keyMatchError = 'drawShedule Objects in arrays must follow the '+
  'pattern of keys of the first Object';

function keyMatch(keyArray) {
  let master = keyArray.shift();

  for (let i = 0; i < keyArray.length; i++) {
    let inner = keyArray[i];
    
    for (let j = 0; j < inner.length; j++) {
      
      if( master.indexOf(inner[j]) < 0 ) {
        return false;
      }
    }
  }
  return true;
}

/**
 * matches the order is objects in a drawShedule object
 * @private
 * @param {Array} isObjects - an undetermined amount of is objects.
 */
export function byKeyOrder(isObjectsArray, stringType){
  const allKeys = isObjectsArray.map(obj => Object.keys(obj));
  
  if ( keyMatch(allKeys) ) {
    const result = allKeys.map(setOfKeys =>
      // get to inner keys
      setOfKeys.map(key =>
        // get to inner objects
        isObjectsArray.map( obj => 
          ({
            type: stringType,
            value: [obj[key]]
          })
        )
      )
    );

    const merged = result[0].map(arr => {
      return arr.reduce((pre, curr) => {
        if(Object.keys(pre).length === 0) {
          return curr;
        } else {
          let value = pre.value.concat(curr.value);
          return Object.assign({}, pre, {value});
        }
      }, {});
    });

    return merged;
  }

  else {
    throw new Error(keyMatchError);
  }
}

/**
 * matches the order of many drawShedule objects
 * @private
 * @param {Array} drawScheduleObjectArray - array of that
 */
export function manyDrawObjects(drawSchObjectArray) {
  const bindArray = drawSchObjectArray.map(drawSchObj => drawSchObj.bind);
  
  const renderArray = drawSchObjectArray.map(drawSchObj => drawSchObj.is);
  
  const orderedBindArray = byKeyOrder(bindArray, BIND);

  const orderedRenderArray = byKeyOrder(renderArray, RENDER);

  return orderedBindArray
    .concat(orderedRenderArray );
}