title: Shallow rendering using enzyme simple test not working
body: <p>I am very new to the enzyme/shallow render testing. I probably don't fully understand it yet.</p>
  
  <p>Using this simplified component:</p>
  
  <pre><code>export const PlacementOption = (props) =&gt; &lt;div/&gt;
  const UpdatingSelectField = (props) =&gt; &lt;div/&gt;
  
  export class DevicePlatforms extends Component{                                                                                                         
    render(){                                                                                                                                             
      return &lt;div&gt;                                                                                                                                        
        &lt;UpdatingSelectField/&gt;
        {this.props.value.device_platforms &amp;&amp; this.props.children}                                                                                        
      &lt;/div&gt;                                                                                                                                              
    }                                                                                                                                                     
  }   
  </code></pre>
  
  <p>I am trying to tests <strong>DevicePlatforms</strong>. If <strong>this.props.value.device_platforms</strong> is not present children are not rendered and if it is they are rendered.</p>
  
  <pre><code>import React from 'react';                                                                                                                              
  import { shallow, mount, render } from 'enzyme';                                                                                                        
  import { DevicePlatforms } from './Placement.js';                                                                                                       
  import { PlacementOption } from './Placement.js'                                                                                                        
  
  describe("&lt;DevicePlatforms/&gt;", function() {                                                                                                             
    it("with all devices selected renders all children", function() {                                                                                     
      const value = {                                                                                                                                     
        device_platforms: "mobile/desktop",                                                                                                               
      }                                                                                                                                                   
      const Component = &lt;DevicePlatforms                                                                                                                  
        value={value}
      &gt;                                                                                                                                                   
        &lt;PlacementOption/&gt;                                                                                                                                
        &lt;PlacementOption/&gt;                                                                                                                                
      &lt;/DevicePlatforms&gt;                                                                                                                                  
  
      const wrapper = shallow(Component)                                                                                                                  
      expect(wrapper.find('PlacementOption')).toBe(2)
    })                                                                                                                                                    
  
    it("with no devices selected renders no children", function() {                                                                                       
      const value = {}                                                                                                                                    
      const Component = &lt;DevicePlatforms                                                                                                                  
        value={value}                                                                                                                                     
      &gt;                                                                                                                                                   
        &lt;PlacementOption/&gt;                                                                                                                                
        &lt;PlacementOption/&gt;                                                                                                                                
      &lt;/DevicePlatforms&gt;                                                                                                                                  
  
      const wrapper = shallow(Component)                                                                                                                  
      expect(wrapper.find('PlacementOption')).toBe(0)                                                                                                     
    })                                                                                                                                                    
  }) 
  </code></pre>
  
  <p>I have tried <strong>'PlacementOption'</strong>, <strong>PlacementOption</strong> in a find call.</p>
  
  <p>All I get is a:</p>
  
  <pre><code>Expected ShallowWrapper({ many many lines of shallow wrapper content }) to be 3
  Expected ShallowWrapper({ many many lines of shallow wrapper content }) to be 0
  </code></pre>
  
  <p>errors.</p>
  
  <p>I can paste the "many many lines of shallow wrapper content" if needed but i don't think it is related and my problem is somewhere else - probably around somewhere around me not knowing how to use shallow render stuff.</p>