/* tslint:disable:no-unused-variable */
import { groupBy, lastItems } from './utils';

describe('utils', () => {

  describe('groupBy', () => {
    beforeEach(() => {
    });

    it('should exist', () => {
      expect(typeof groupBy).toBe('function');
    });

    it('should group an array of objects into an object of arrays, with a STRING as an identifier', () => {
      const data = [{a: 1}, {a: 2}, {b: 3}, {a: 1}];
      const result = groupBy(data, 'a');

      expect(result[1].length).toBe(2);
      expect(result[2].length).toBe(1);
      expect(result['undefined'].length).toBe(1);
      expect(Object.keys(result).length).toBe(3);

      expect(result[1]).toContain(data[0]);
      expect(result[1]).toContain(data[3]);
      expect(result[2]).toContain(data[1]);
      expect(result['undefined']).toContain(data[2]);
    });

    it('should group an array of objects into an object of arrays with a FUNCTION as an identifier', () => {
      const data = [{a: {b: 'x'}}, {a: {b: 'y'}}, {a: {b: 'x'}}, {a: {b: 'y'}}, {a: {b: 'z'}}];
      const result = groupBy(data, (value) => value['a']['b']);

      expect(result['x'].length).toBe(2);
      expect(result['y'].length).toBe(2);
      expect(result['z'].length).toBe(1);
      expect(Object.keys(result).length).toBe(3);

      expect(result['x']).toContain(data[0]);
      expect(result['y']).toContain(data[1]);
      expect(result['x']).toContain(data[2]);
      expect(result['y']).toContain(data[3]);
      expect(result['z']).toContain(data[4]);
    });
  });
});