accounts-frontend/packages/app/components/ui/popup/reducer.test.js

import expect from 'app/test/unexpected';
import React from 'react';
import reducer from 'app/components/ui/popup/reducer';
import { create, destroy } from 'app/components/ui/popup/actions';

describe('popup/reducer', () => {
  it('should have no popups by default', () => {
    const actual = reducer(undefined, {
      type: 'init',
    });

    expect(actual.popups, 'to be an', 'array');
    expect(actual.popups, 'to be empty');
  });

  describe('#create', () => {
    it('should create popup', () => {
      const actual = reducer(
        undefined,
        create({
          Popup: FakeComponent,
        }),
      );

      expect(actual.popups[0], 'to equal', {
        Popup: FakeComponent,
      });
    });

    it('should create multiple popups', () => {
      let actual = reducer(
        undefined,
        create({
          Popup: FakeComponent,
        }),
      );
      actual = reducer(
        actual,
        create({
          Popup: FakeComponent,
        }),
      );

      expect(actual.popups[1], 'to equal', {
        Popup: FakeComponent,
      });
    });

    it('throws when no type provided', () => {
      expect(
        () =>
          reducer(
            undefined,
            // @ts-ignore
            create({}),
          ),
        'to throw',
        'Popup is required',
      );
    });
  });

  describe('#destroy', () => {
    let state;
    let popup;

    beforeEach(() => {
      state = reducer(state, create({ Popup: FakeComponent }));
      popup = state.popups[0];
    });

    it('should remove popup', () => {
      expect(state.popups, 'to have length', 1);

      state = reducer(state, destroy(popup));

      expect(state.popups, 'to have length', 0);
    });

    it('should not remove something, that it should not', () => {
      state = reducer(
        state,
        create({
          Popup: FakeComponent,
        }),
      );

      state = reducer(state, destroy(popup));

      expect(state.popups, 'to have length', 1);
      expect(state.popups[0], 'not to be', popup);
    });
  });
});

function FakeComponent() {
  return <span />;
}