wix-style-react/src/utils/operators/pickBy.spec.js

wix-style-react

import pickBy from './pickBy';
import sinon from 'sinon';

describe('pickBy operator', () => {
  it('should return an empty object for non-object input', () => {
    expect(pickBy(1)).toEqual({});
    expect(pickBy(true)).toEqual({});
    expect(pickBy('')).toEqual({});
    expect(pickBy(null)).toEqual({});
    expect(pickBy(undefined)).toEqual({});
    expect(pickBy(Symbol.for('foo'))).toEqual({});
  });

  it('should return an empty object for non-function pick function', () => {
    expect(pickBy({ a: 1 }, 'not-a-function')).toEqual({});
  });

  it('should return given input', () => {
    expect(pickBy({ a: 1 })).toEqual({ a: 1 });
  });

  it('should pick input values by predicate', () => {
    const anObject = { a: 1, b: 2, c: 3, d: 4, e: 5, f: 6 };
    const biggerThanThree = value => value > 3;
    expect(pickBy(anObject, biggerThanThree)).toEqual({ d: 4, e: 5, f: 6 });
  });

  it('should call predicate with (value, key)', () => {
    const anObject = { a: 1 };
    const pickFunc = sinon.spy();
    pickBy(anObject, pickFunc);

    expect(pickFunc.calledWithExactly(1, 'a'));
  });
});