title: Is it possibly for JEST mocks to be overwritten by each other?
body: <p>I have two tests that look something like:</p>
  <pre><code>import someThing from '../someThing';
  jest.mock('../someThing');
  
  describe('group', () =&gt; {
      it('test #1', async () =&gt; {
          someThing.someFunction.mockImplementation(() =&gt; 123);
      });
      it('test #2', async () =&gt; {
          someThing.someFunction.mockImplementation(() =&gt; 456);
      });
  });
  
  </code></pre>
  <p>I'm seeing an issue where it appears the mockImplementation from the first test is being called in the second test. If I disable test #1 test# 2 works as expected. (My actual code is more complicated than this).</p>
  <p>The reason I need a separate mock for both is that one is supposed to return a failure result and one is supposed to return a success one given the same input.</p>
  <p>From what I understand, JEST runs all test in parallel so I'm assuming what's happening is that the mockImplementation is being modified by both tests at the same time as it's the same import.</p>