title: Why Jest (JavaScript framework for unit testing) does not work with `this`?
body: <pre><code>class Test {
    static Test1 () { console.log(this); this.Test2();  }
    static Test2 () { console.log('qwe'); }
  }
  
  Test.Test1();
  
  export default Test;
  export const Test1 = Test.Test1;
  </code></pre>
  
  <p>Compiled with BabelJS with ES2015 preset. With <code>node</code> the compiled code runs fine. But within unit test <code>this</code> is <code>undefined</code>. Why this happens?</p>