$ yarn test
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  viewOfInterval()
    ✓ returns a day interval for day view (2ms)
    ✓ returns a week interval for week view (2ms)
    ✕ returns a month interval for month view (7ms)
    ✓ returns a year interval for year view (30ms)
  viewOfDays()
    ✕ returns day intervals for view and datetime (5ms)
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   ● viewOfInterval() › returns a month interval for month view

    expect(received).toBe(expected) // Object.is equality

    Expected: 31
    Received: 42

      87 |     const datetime = DateTime.fromObject({ year: 2019, month: 12, day: 30 });
      88 |     const interval = viewOfInterval(datetime, 'months');
    > 89 |     expect(numUnit(interval, 'days')).toBe(31);
         |                                       ^
      90 |     expect(interval.start.day).toBe(1);
      91 |     expect(interval.end.day).toBe(31);
      92 |   });

      at Object.<anonymous> (test/calx.test.tsx:89:39)

  ● viewOfDays() › returns day intervals for view and datetime

    expect(received).toBe(expected) // Object.is equality

    Expected: 31
    Received: 42

      108 |     const datetime = DateTime.fromObject({ year: 2019, month: 12, day: 30 });
      109 |     const days = viewOfDays(datetime, 'month');
    > 110 |     expect(days.length).toBe(31);
          |                         ^
      111 |     expect(days[0].start.day).toBe(1);
      112 |     expect(days[30].start.day).toBe(31);
      113 |   });

      at Object.<anonymous> (test/calx.test.tsx:110:25)
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Test Suites: 1 failed, 1 total
Tests:       2 failed, 19 passed, 21 total
Snapshots:   0 total
Time:        2.416s, estimated 4s