ГОГНОКОДЕ

gistfile1.txt

  class Enumerable {
  constructor(collection, operations) {
    this.collection = collection;
    this.operations = operations || [];
  }

  build(fn) {
    return new Enumerable(this.collection.slice(), this.operations.concat(fn));
  }

  // BEGIN (write your solution here)
  where(...theArgs) {
    const newOp = this.operations.slice();
    const newEl = this.collection.slice();
    theArgs.forEach((element) => {
      if (typeof element === 'function') {
        newOp.push(coll => coll.filter(element));
      }
    });

    let filteredArray = newEl;
    const selObj = theArgs.filter(element1 => typeof element1 !== 'function');
    selObj.forEach((key1) => {
      const keyObj = Object.keys(key1);
      keyObj.forEach((key2) => {
        const valueObj = key1[key2];
        filteredArray = newEl.filter(element2 => element2[key2] === valueObj);
      });
    });
    return new Enumerable(filteredArray, newOp);
  }
  // END

  get length() {
    return this.toArray().length;
  }

  toArray() {
    if (!this.memo) {
      this.memo = this.operations.reduce((acc, func) => func(acc), this.collection);
    }

    return this.memo;
  }
}

export default Enumerable;