Fix server render strict mode

packages/react-dom/src/__tests__/ReactDOMServerIntegrationFragment-test.js

@@ -99,7 +99,7 @@ describe('ReactDOMServerIntegration', () => {
       expect(parent.childNodes[2].tagName).toBe('P');
     });
 
-    itRenders('an empty framgent', async render => {
+    itRenders('an empty fragment', async render => {
       expect(await render(<React.Fragment />)).toBe(null);
     });
   });

packages/react-dom/src/__tests__/ReactDOMServerIntegrationStrictMode-test.js

@@ -0,0 +1,106 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @emails react-core
+ */
+
+'use strict';
+
+const ReactDOMServerIntegrationUtils = require('./utils/ReactDOMServerIntegrationTestUtils');
+
+let React;
+let ReactDOM;
+let ReactDOMServer;
+
+function initModules() {
+  // Reset warning cache.
+  jest.resetModuleRegistry();
+  React = require('react');
+  ReactDOM = require('react-dom');
+  ReactDOMServer = require('react-dom/server');
+
+  // Make them available to the helpers.
+  return {
+    ReactDOM,
+    ReactDOMServer,
+  };
+}
+
+const {resetModules, itRenders} = ReactDOMServerIntegrationUtils(initModules);
+
+describe('ReactDOMServerIntegration', () => {
+  beforeEach(() => {
+    resetModules();
+  });
+
+  describe('React.StrictMode', () => {
+    itRenders('a strict mode with one child', async render => {
+      let e = await render(
+        <React.StrictMode>
+          <div>text1</div>
+        </React.StrictMode>,
+      );
+      let parent = e.parentNode;
+      expect(parent.childNodes[0].tagName).toBe('DIV');
+    });
+
+    itRenders('a strict mode with several children', async render => {
+      let Header = props => {
+        return <p>header</p>;
+      };
+      let Footer = props => {
+        return (
+          <React.StrictMode>
+            <h2>footer</h2>
+            <h3>about</h3>
+          </React.StrictMode>
+        );
+      };
+      let e = await render(
+        <React.StrictMode>
+          <div>text1</div>
+          <span>text2</span>
+          <Header />
+          <Footer />
+        </React.StrictMode>,
+      );
+      let parent = e.parentNode;
+      expect(parent.childNodes[0].tagName).toBe('DIV');
+      expect(parent.childNodes[1].tagName).toBe('SPAN');
+      expect(parent.childNodes[2].tagName).toBe('P');
+      expect(parent.childNodes[3].tagName).toBe('H2');
+      expect(parent.childNodes[4].tagName).toBe('H3');
+    });
+
+    itRenders('a nested strict mode', async render => {
+      let e = await render(
+        <React.StrictMode>
+          <React.StrictMode>
+            <div>text1</div>
+          </React.StrictMode>
+          <span>text2</span>
+          <React.StrictMode>
+            <React.StrictMode>
+              <React.StrictMode>
+                {null}
+                <p />
+              </React.StrictMode>
+              {false}
+            </React.StrictMode>
+          </React.StrictMode>
+        </React.StrictMode>,
+      );
+      let parent = e.parentNode;
+      expect(parent.childNodes[0].tagName).toBe('DIV');
+      expect(parent.childNodes[1].tagName).toBe('SPAN');
+      expect(parent.childNodes[2].tagName).toBe('P');
+    });
+
+    itRenders('an empty strict mode', async render => {
+      expect(await render(<React.StrictMode />)).toBe(null);
+    });
+  });
+});

packages/react-dom/src/server/ReactPartialRenderer.js

@@ -28,6 +28,7 @@ import {ReactDebugCurrentFrame} from 'shared/ReactGlobalSharedState';
 import {warnAboutDeprecatedLifecycles} from 'shared/ReactFeatureFlags';
 import {
   REACT_FRAGMENT_TYPE,
+  REACT_STRICT_MODE_TYPE,
   REACT_CALL_TYPE,
   REACT_RETURN_TYPE,
   REACT_PORTAL_TYPE,
@@ -814,6 +815,7 @@ class ReactDOMServerRenderer {
       }
 
       switch (elementType) {
+        case REACT_STRICT_MODE_TYPE:
         case REACT_FRAGMENT_TYPE: {
           const nextChildren = toArray(
             ((nextChild: any): ReactElement).props.children,