react-native-ui-lib/src/incubator/WheelPicker/__tests__/usePresenter.spec.js

<p align="center"> <img src="https://user-images.githubusercontent.com/1780255/105469025-56759000-5ca0-11eb-993d-3568c1fd54f4.png" height="250px" style="display:block"/> </p> <p align="center">UI Toolset & Components Library for React Native</p> <p a

import usePresenter from '../usePresenter';
import {renderHook} from '@testing-library/react-hooks';

describe('WheelPicker presenter tests', () => {
  const makeSUT = ({items = makeItems(9), children, initialValue, itemHeight = 10, preferredNumVisibleRows = 20}) => {
    return renderHook(() =>
      usePresenter({
        items,
        children,
        initialValue,
        itemHeight,
        preferredNumVisibleRows
      }));
  };

  const makeItems = (count, stringValue) => {
    const items = [];
    while (count >= items.length) {
      const someData = stringValue ? stringValue + items.length : items.length;
      const item = {value: someData, label: someData};
      items.push(item);
    }
    return items;
  };

  it('expect height of the content-view to be itemHeight * preferredNumVisibleRows', () => {
    let sut = makeSUT({items: makeItems(44), itemHeight: 10, preferredNumVisibleRows: 5});
    expect(sut.result.current.height).toEqual(50);

    sut = makeSUT({items: makeItems(10), itemHeight: 20, preferredNumVisibleRows: 3});
    expect(sut.result.current.height).toEqual(60);

    sut = makeSUT({items: makeItems(10), itemHeight: 0, preferredNumVisibleRows: 0});
    expect(sut.result.current.height).toEqual(0);
  });

  it('Expect to find items by their string types', () => {
    let sut = makeSUT({items: makeItems(15, 'a'), initialValue: 'a2'});
    expect(sut.result.current.index).toEqual(2);

    sut = makeSUT({items: makeItems(100, 'bbb'), initialValue: 'bbb71'});
    expect(sut.result.current.index).toEqual(71);

    // no data found
    sut = makeSUT({items: makeItems(10, 'b'), initialValue: '$$$'});
    expect(sut.result.current.index).toEqual(-1);
  });

  it('Expect to find items by their number types', () => {
    let sut = makeSUT({items: makeItems(11), initialValue: 0});
    expect(sut.result.current.index).toEqual(0);

    sut = makeSUT({items: makeItems(8), initialValue: 4});
    expect(sut.result.current.index).toEqual(4);

    sut = makeSUT({items: makeItems(18), initialValue: 18});
    expect(sut.result.current.index).toEqual(18);

    sut = makeSUT({items: makeItems(18), initialValue: 99});
    expect(sut.result.current.index).toEqual(-1);

    sut = makeSUT({items: makeItems(0), initialValue: 99});
    expect(sut.result.current.index).toEqual(-1);

    sut = makeSUT({items: makeItems(0), initialValue: 0});
    expect(sut.result.current.index).toEqual(0);
  });

  it('Expect to find items by their object of {value, label} types', () => {
    const {result} = makeSUT({items: makeItems(15, 'b'), initialValue: {value: 'b6', label: 'abc'}});
    expect(result.current.index).toEqual(6);
  });

  it('Expect getRowItemAtOffset to return the right row for offset', () => {
    let sut = makeSUT({initialValue: 2, itemHeight: 100});

    let offset = 300;
    expect(sut.result.current.getRowItemAtOffset(offset).value).toEqual(3);

    sut = makeSUT({initialValue: 0, itemHeight: 100});
    offset = 0;
    expect(sut.result.current.getRowItemAtOffset(offset).value).toEqual(0);
  });
});