set allchunks: true for ExtractTextPlugin

Author: viankakrisna

packages/react-scripts/config/webpack.config.prod.js

@@ -412,6 +412,10 @@ module.exports = {
     }),
     // Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
     new ExtractTextPlugin({
+      // Turning this on because we want all css to be included in the main
+      // css bundle when doing code splitting to avoid FOUC:
+      // https://github.com/facebook/create-react-app/issues/2415
+      allChunks: true,
       filename: cssFilename,
     }),
     // Generate a manifest file which contains a mapping of all asset filenames

packages/react-scripts/fixtures/kitchensink/integration/webpack.test.js

@@ -17,8 +17,10 @@ describe('Integration', () => {
         doc.getElementsByTagName('style')[0].textContent.replace(/\s/g, '')
       ).to.match(/html\{/);
       expect(
-        doc.getElementsByTagName('style')[1].textContent.replace(/\s/g, '')
+        doc.getElementsByTagName('style')[0].textContent.replace(/\s/g, '')
       ).to.match(/#feature-css-inclusion\{background:.+;color:.+}/);
+      // we expect to only have one style tag when allChunks: true
+      expect(doc.getElementsByTagName('style').length).to.equal(1);
     });
 
     it('css modules inclusion', async () => {