updeep-remeda/test/reject-spec.js

import { expect } from 'chai';
import u from '../lib';

describe('u.reject', () => {
  it('can reject by index', () => {
    const result = u.reject((_, index) => index === 1, [3, 4, 5]);

    expect(result).to.eql([3, 5]);
  });

  it('can reject with callback shorthand', () => {
    const result = u.reject('bad', [{ bad: true }, { bad: false }]);

    expect(result).to.eql([{ bad: false }]);
  });

  it('returns the same instance if reject doesn\'t make changes', () => {
    const object = { foo: [1, 2, 3] };
    const result = u({
      foo: u.reject(x => x === 'Justin Bieber'),
    }, object);

    expect(result).to.equal(object);
  });

  it('returns a different instance if reject makes changes', () => {
    const object = { foo: [1, 2, 3, 4] };
    const result = u({
      foo: u.reject(x => x === 4),
    }, object);

    expect(result).to.not.equal(object);
  });

  it('freezes the result', () => {
    expect(Object.isFrozen(u.reject('a', []))).to.be.true;
  });
});