react-hold/es/__tests__/utils-test.js

Hold the empty presentational components in react.js

import React from 'react';
import { isNull, isObject, isFunction, getDisplayName } from '../utils';

describe('utils', function () {
  it('isNull', function () {
    expect(isNull()).toBeTruthy();
    expect(isNull(null)).toBeTruthy();

    expect(isNull('')).toBeFalsy();
    expect(isNull(0)).toBeFalsy();
  });

  it('isObject', function () {
    expect(isObject()).toBeFalsy();
    expect(isObject(null)).toBeFalsy();
    expect(isObject('')).toBeFalsy();
    expect(isObject(0)).toBeFalsy();
    expect(isObject([])).toBeFalsy();

    expect(isObject({})).toBeTruthy();
    expect(isObject({ foo: 'bar' })).toBeTruthy();
  });

  it('isFunction', function () {
    expect(isFunction()).toBeFalsy();
    expect(isFunction({})).toBeFalsy();
    expect(isFunction([])).toBeFalsy();

    expect(isFunction(function () {})).toBeTruthy();
  });

  it('getDisplayName', function () {
    var Component1 = function Component1() {
      return React.createElement(
        'div',
        null,
        'foo'
      );
    };
    var Component2 = function Component2() {
      return React.createElement(
        'div',
        null,
        'bar'
      );
    };
    Component2.displayName = 'Bar';
    expect(getDisplayName(Component1)).toBe('Component1');
    expect(getDisplayName(Component2)).toBe('Bar');
    expect(getDisplayName('div')).toBe('div');
  });
});