title: TypeError: Cannot read property 'find' of undefined in React-redux while running a test
body: <p>I know there has been a lot of "cannot read property ".find" fo undefined" questions, but I have been looking at them and have not found an answer that I am looking for. 
  I am running a test of my components.. and this one does not pass.. I was able to make the other tests pass.. but the ".find" returns an undefined error.. been looking at it the whole morning, but cannot find the solution.. can anybody help me?
  Here is the commentList.test.js file:</p>
  
  <pre><code>import React from 'react';
  import { mount } from 'enzyme';
  
  import { CommentList } from 'components/commentList';
  import Root from 'Root';
  
  let wrapped;
  beforeEach(() =&gt; {
    const initialState = {
      comments: ['Comment 1', 'Comment 2']
    };
  
    wrapped = mount(
      &lt;Root initialState={initialState}&gt;
        &lt;CommentList /&gt;
      &lt;/Root&gt;
    );
  });
  
  it('creates one LI per comment', () =&gt; {
    expect(wrapped.find('li').length).toEqual(2);
  });
  </code></pre>
  
  <p>Here is the commentList.js file</p>
  
  <pre><code>import { connect } from 'react-redux';
  import React, { Component } from 'react';
  
  class CommentList extends Component {
    renderComments() {
      return this.props.comments.map(comment  =&gt; {
        return &lt;li key={comment}&gt;{comment}&lt;/li&gt;
      })
    }
  
    render() {
        return (
          &lt;div&gt;
            &lt;ul&gt;
              {this.renderComments()}
            &lt;/ul&gt;
        &lt;/div&gt;
      )
  }
  }
  
  const mapStateToProps = (state) =&gt; {
    return {
      comments: state.comments
    };
  }
  
  export default connect(mapStateToProps)(CommentList);
  </code></pre>
  
  <p>and finally the Root.js file:</p>
  
  <pre><code>import React from 'react';
  import { Provider } from 'react-redux';
  import { createStore } from 'redux';
  import reducers from 'reducers';
  
  export default ({ children, initialState = {} }) =&gt; {
    return (
      &lt;Provider store={createStore(reducers, initialState)}&gt;
        {children}
      &lt;/Provider&gt;
    )
  }
  </code></pre>
  
  <p>Here is what can bee seen in my terminal
  <a href="https://i.stack.imgur.com/mnqtA.png" rel="nofollow noreferrer">enter image description here</a></p>