[enzyme-adapter-react-16] [new] Added support for React.memo

enzymejs · Nov 22, 2018 · ba622ce · ba622ce
1 parent 0a89b1f
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diff --git a/packages/enzyme-adapter-react-16/src/ReactSixteenAdapter.js b/packages/enzyme-adapter-react-16/src/ReactSixteenAdapter.js
@@ -22,6 +22,8 @@ import {
   ForwardRef,
   Profiler,
   Portal,
+  isMemo,
+  Memo,
 } from 'react-is';
 import { EnzymeAdapter } from 'enzyme';
 import { typeOfNode } from 'enzyme/build/Utils';
@@ -94,7 +96,6 @@ function elementToTree(el) {
 
   const { children, containerInfo } = el;
   const props = { children, containerInfo };
-
   return {
     nodeType: 'portal',
     type: Portal,
@@ -143,6 +144,7 @@ function toTree(vnode) {
         instance: node.stateNode,
         rendered: childrenToTree(node.child),
       };
+    case FiberTags.Memo:
     case FiberTags.FunctionalComponent:
       return {
         nodeType: 'function',
@@ -357,6 +359,16 @@ class ReactSixteenAdapter extends EnzymeAdapter {
             || Array.isArray(Component.__reactAutoBindPairs) // fallback for createClass components
           );
 
+
+          if (!isStateful && isMemo(el)) {
+            const InnerComp = el.type.type;
+            const wrappedEl = Object.assign(
+              (...args) => InnerComp(...args), // eslint-disable-line new-cap
+              InnerComp,
+            );
+            return withSetStateAllowed(() => renderer.render({ ...el, type: wrappedEl }, context));
+          }
+
           if (!isStateful && typeof Component === 'function') {
             const wrappedEl = Object.assign(
               (...args) => Component(...args), // eslint-disable-line new-cap
@@ -513,6 +525,7 @@ class ReactSixteenAdapter extends EnzymeAdapter {
     switch ($$typeofType) {
       case ContextConsumer || NaN: return 'ContextConsumer';
       case ContextProvider || NaN: return 'ContextProvider';
+      case Memo || NaN: return 'Memo';
       case ForwardRef || NaN: {
         if (type.displayName) {
           return type.displayName;

diff --git a/packages/enzyme-adapter-react-16/src/detectFiberTags.js b/packages/enzyme-adapter-react-16/src/detectFiberTags.js
@@ -18,6 +18,7 @@ module.exports = function detectFiberTags() {
   const supportsMode = typeof React.StrictMode !== 'undefined';
   const supportsContext = typeof React.createContext !== 'undefined';
   const supportsForwardRef = typeof React.forwardRef !== 'undefined';
+  const supportsMemo = typeof React.memo !== 'undefined';
 
   function Fn() {
     return null;
@@ -44,6 +45,9 @@ module.exports = function detectFiberTags() {
     ClassComponent: getFiber(React.createElement(Cls)).tag,
     Fragment: getFiber([['nested']]).tag,
     FunctionalComponent: getFiber(React.createElement(Fn)).tag,
+    Memo: supportsMemo
+      ? getFiber(React.createElement(React.memo(Fn))).tag
+      : -1,
     HostPortal: getFiber(ReactDOM.createPortal(null, global.document.createElement('div'))).tag,
     HostComponent: getFiber(React.createElement('span')).tag,
     HostText: getFiber('text').tag,

diff --git a/packages/enzyme-test-suite/test/ReactWrapper-spec.jsx b/packages/enzyme-test-suite/test/ReactWrapper-spec.jsx
@@ -28,6 +28,7 @@ import {
   createRef,
   Fragment,
   forwardRef,
+  memo,
   PureComponent,
 } from './_helpers/react-compat';
 import {
@@ -461,6 +462,40 @@ describeWithDOM('mount', () => {
       expect(wrapper.find(TestItem)).to.have.lengthOf(3);
       expect(wrapper.find(TestItem).first().props().test).to.equal('123');
     });
+
+    itIf(is('>= 16.6'), 'works with memo', () => {
+      const InnerComp = () => <div><span>Hello</span></div>;
+      const Foo = memo(({ foo }) => (
+        <div>
+          <InnerComp />
+          <div className="bar">bar</div>
+          <div className="qoo">{foo}</div>
+        </div>
+      ));
+
+      const wrapper = mount(<Foo foo="qux" />);
+      expect(wrapper.debug()).to.equal(`<Component foo="qux">
+  <div>
+    <InnerComp>
+      <div>
+        <span>
+          Hello
+        </span>
+      </div>
+    </InnerComp>
+    <div className="bar">
+      bar
+    </div>
+    <div className="qoo">
+      qux
+    </div>
+  </div>
+</Component>`);
+      expect(wrapper.find('InnerComp')).to.have.lengthOf(1);
+      expect(wrapper.find('.bar')).to.have.lengthOf(1);
+      expect(wrapper.find('.qoo').text()).to.equal('qux');
+    });
+
   });
 
   describeIf(is('>= 16'), 'portals', () => {

diff --git a/packages/enzyme-test-suite/test/ShallowWrapper-spec.jsx b/packages/enzyme-test-suite/test/ShallowWrapper-spec.jsx
@@ -28,6 +28,7 @@ import {
   createRef,
   Fragment,
   forwardRef,
+  memo,
   PureComponent,
 } from './_helpers/react-compat';
 import {
@@ -1273,6 +1274,47 @@ describe('shallow', () => {
         expect(wrapper.find(Component.displayName)).to.have.lengthOf(2);
       });
     });
+
+    describeIf(is('>= 16.6'), 'memo', () => {
+      it('renders memoized component', () => {
+        const Component = () => <div>Memoized component</div>;
+        const ComponentWithMemo = memo(Component);
+
+        const wrapper = shallow(<ComponentWithMemo />);
+        expect(wrapper.find('div')).to.have.lengthOf(1);
+        expect(wrapper.debug()).to.equal(`<div>
+  Memoized component
+</div>`);
+      });
+
+      it('renders memoized component and passes the props', () => {
+        const Component = ({ title }) => <div><span>{title}</span></div>;
+        const ComponentWithMemo = memo(Component);
+
+        const wrapper = shallow(<ComponentWithMemo title="memo test" />);
+        expect(wrapper.find('span').text()).to.equal('memo test');
+      });
+
+      it('finds memo', () => {
+        const Component = memo(() => <div />);
+        Component.displayName = 'CustomMemo';
+        class Foo extends React.Component {
+          render() {
+            return (
+              <div>
+                <Component />
+                <Component />
+              </div>
+            );
+          }
+        }
+
+        const wrapper = shallow(<Foo />);
+        expect(wrapper.find(Component)).to.have.lengthOf(2);
+        expect(wrapper.find('Memo')).to.have.lengthOf(2);
+      });
+    });
+
   });
 
   describe('.findWhere(predicate)', () => {