<!--
  Note: if the issue is about documentation or the website, please file it at:
  https://github.com/reactjs/reactjs.org/issues/new
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**Do you want to request a *feature* or report a *bug*?**
Bug. Behavior regression.

**What is the current behavior?**
Package throws when being required in Node.

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem. Your bug will get fixed much faster if we can run your code and it doesn't have dependencies other than React. Paste the link to your JSFiddle (https://jsfiddle.net/Luktwrdm/) or CodeSandbox (https://codesandbox.io/s/new) example below:**

```
avi@localhost  ~/projects/r168  node
> require('react-dom/test-utils')
ReferenceError: document is not defined
    at /home/avi/projects/r168/node_modules/react-dom/cjs/react-dom-test-utils.development.js:944:27
    at Object.<anonymous> (/home/avi/projects/r168/node_modules/react-dom/cjs/react-dom-test-utils.development.js:1283:5)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Module.require (internal/modules/cjs/loader.js:637:17)
    at require (internal/modules/cjs/helpers.js:22:18)
```

**What is the expected behavior?**
`react-dom/test-utils` should not throw in "pure" node (without `jsdom` providing fake document on global).

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
happens on 16.8.0
previous versions work.
nodeType: 'host',
          props: {},
          instance: null,
          rendered: ['Four'],
        },
      ]),
    );
  });
  it('root instance and createNodeMock ref return the same value', () => {
    const createNodeMock = ref => ({node: ref});
    let refInst = null;
    const renderer = ReactTestRenderer.create(
      <div ref={ref => (refInst = ref)} />,
      {createNodeMock},
    );
    const root = renderer.getInstance();
    expect(root).toEqual(refInst);
  });
  it('toTree() renders complicated trees of composites and hosts', () => {
    
    const Qoo = () => <span className="Qoo">Hello World!</span>;
    
    const Foo = ({className, children}) => (
      <div className={'Foo ' + className}>
        <span className="Foo2">Literal</span>
        {children}
      </div>
    );
    
    class Bar extends React.Component {