Add adapter check and conditional to update or not

Author: sstern6

packages/enzyme-adapter-react-16/src/ReactSixteenAdapter.js

@@ -28,7 +28,7 @@ import {
   Memo,
 } from 'react-is';
 import { EnzymeAdapter } from 'enzyme';
-import { typeOfNode } from 'enzyme/build/Utils';
+import { typeOfNode, shallowEqual } from 'enzyme/build/Utils';
 import {
   displayNameOfNode,
   elementToTree as utilElementToTree,
@@ -617,10 +617,12 @@ class ReactSixteenAdapter extends EnzymeAdapter {
     return isElement(element);
   }
 
-  shouldUpdateComponent(root, nodes) {
-    // not sure how to compare prevState/prevProps with current state/props for nodes here.
-    // store values on the instance?
-    return hasRootNodeChanged(root);
+  shouldUpdateComponent(prevProps, root) {
+    if (root.instance() !== null) {
+      return (
+        root.instance().updater._renderer._newState !== null || !shallowEqual(prevProps, root.instance().props)
+      );
+    }
   }
 
   isValidElementType(object) {

packages/enzyme-test-suite/test/ShallowWrapper-spec.jsx

@@ -1147,7 +1147,7 @@ describe('shallow', () => {
       expect(wrapper.find('.b').find('.c')).to.have.lengthOf(6);
     });
 
-    it('is able to call find on the same wrapper more than once', () => {
+    it('can call find on the same wrapper more than once', () => {
       class TestComponent extends React.Component {
         render() {
           return (
@@ -3609,10 +3609,6 @@ describe('shallow', () => {
       });
     });
 
-    describe('getNodesInternal', () => {
-
-    });
-
     it('does not return true for HTML elements', () => {
       const wrapper = shallow(<div className="bar baz" />);
       expect(wrapper.isEmptyRender()).to.equal(false);

packages/enzyme/src/ShallowWrapper.js

@@ -361,9 +361,14 @@ class ShallowWrapper {
    */
   getNodesInternal() {
     const adapter = getAdapter(this[OPTIONS]);
+    const prevProps = (this[UNRENDERED] && this[UNRENDERED].props) || {};
 
     if (this[ROOT] === this && this.length === 1) {
-      if (adapter.shouldUpdateComponent(this[ROOT], this[NODES])) {
+      if (adapter.shouldUpdateComponent) {
+        if (adapter.shouldUpdateComponent(prevProps, this[ROOT])) {
+          this.update();
+        }
+      } else {
         this.update();
       }
     }