tenfold.js

function checkType(item, test) {
  const parsedTest = Array.isArray(test) ? test[0] : test;
  return item.constructor === parsedTest;
}

function checkArrayType(value, test) {
  const result = [];
  value.forEach((item, i) => {
    if (typeof item === 'object') {
      result.push(checkObjectType(item, test[i]));
    } else if (checkType(item, test)) {
      result.push(item);
    }
  });
  return result;
}

function checkObjectType(value, test) {
  const keys = Object.keys(value);
  const result = {};

  keys.forEach((key) => {
    const newValue = value[key];

    debugger;
    if (Array.isArray(newValue) && test) {
      result[key] = checkArrayType(newValue, test[key]);
    } else if (typeof newValue === 'object' && test) {
      result[key] = checkObjectType(newValue, test[key]);
    } else if (test && test[key] && checkType(newValue, test[key])) {
      result[key] = newValue;
    }
  });
  return result;
}

function nestedTypeFilter(value, test) {
  if (value === null) {
    return undefined;
  }

  if (Array.isArray(test) || Array.isArray(value)) {
    return checkArrayType(value, test);
  }

  if (typeof value === 'object') {
    return checkObjectType(value, test);
  }

  if (checkType(value, test)) {
    return value;
  }

  return undefined;
}

module.exports = nestedTypeFilter;