Add warning about implicit dependency on react-addons-test-utils

src/react-compat.js

@@ -62,15 +62,36 @@ if (REACT013) {
     return TestUtils.renderIntoDocument(node);
   };
 } else {
-  const ReactDOM = require('react-dom');
+  let ReactDOM;
+
+  try {
+    ReactDOM = require('react-dom');
+  } catch (e) {
+    console.error(
+      'react-dom is an implicit dependency in order to support [email protected]. ' +
+      'Please add the appropriate version to your devDependencies. ' +
+      'See https://github.com/airbnb/enzyme#installation'
+    );
+    throw e;
+  }
+
   renderToStaticMarkup = require('react-dom/server').renderToStaticMarkup;
   findDOMNode = ReactDOM.findDOMNode;
   unmountComponentAtNode = ReactDOM.unmountComponentAtNode;
   // We require the testutils, but they don't come with 0.14 out of the box, so we
   // require them here through this node module. The bummer is that we are not able
   // to list this as a dependency in package.json and have 0.13 work properly.
   // As a result, right now this is basically an implicit dependency.
-  TestUtils = require('react-addons-test-utils');
+  try {
+    TestUtils = require('react-addons-test-utils');
+  } catch (e) {
+    console.error(
+      'react-addons-test-utils is an implicit dependency in order to support [email protected]. ' +
+      'Please add the appropriate version to your devDependencies. ' +
+      'See https://github.com/airbnb/enzyme#installation'
+    );
+    throw e;
+  }
 
   // Shallow rendering changed from 0.13 => 0.14 in such a way that
   // 0.14 now does not allow shallow rendering of native DOM elements.