import {PairsPipe} from './pairs';

describe('PairsPipe', () => {
  let pipe: PairsPipe;

  beforeEach(() => {
    pipe = new PairsPipe();
  });

  it('should keep the element the same way if its not an object', () => {
    expect(pipe.transform([1, 2, 3])).toEqual([1, 2, 3]);
    expect(pipe.transform([])).toEqual([]);
    expect(pipe.transform('foo')).toEqual('foo');
    expect(pipe.transform(null)).toEqual(null);
    expect(pipe.transform(undefined)).toEqual(undefined);
  });

  it('should return array of pairs', () => {
    expect(pipe.transform({})).toEqual([]);
    expect(pipe.transform({foo: 'bar'})).toEqual([['foo', 'bar']]);
    expect(pipe.transform({foo: 1, bar: 42})).toEqual([['foo', 1],['bar', 42]]);
    expect(pipe.transform({foo: [1, 2], bar: {a: 2}})).toEqual([['foo', [1, 2]],['bar', {a: 2}]]);
  });
});