Refine how TypeScript env types are handled (#5593)

* Specify types in package

* Do not remove types file on eject

* Stop copying types into generated project

* Reference react and react-dom

* Reference node types

* Install node types as well

* Restore copying

* Add Node to the list of installed types

* Reference Jest types

* Remove jest types from install

* Remove jest from CRA install

* Remove Jest reference and let user do this themselves

* Stop copying types file

* Add types key to package.json

* Add appTypeDeclarations and create when missing

* Rename declarations file

* Add Jest back to install instructions

* Minimize diff

packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js

@@ -238,21 +238,13 @@ function verifyTypeScriptSetup() {
     writeJson(paths.appTsConfig, appTsConfig);
   }
 
-  // Copy type declarations associated with this version of `react-scripts`
-  const declaredTypes = path.resolve(
-    __dirname,
-    '..',
-    '..',
-    'config',
-    'react-app.d.ts'
-  );
-  const declaredTypesContent = fs
-    .readFileSync(declaredTypes, 'utf8')
-    .replace(/\/\/ @remove-file-on-eject\r?\n/, '');
-  fs.writeFileSync(
-    path.resolve(paths.appSrc, 'react-app.d.ts'),
-    declaredTypesContent
-  );
+  // Reference `react-scripts` types
+  if (!fs.existsSync(paths.appTypeDeclarations)) {
+    fs.writeFileSync(
+      paths.appTypeDeclarations,
+      `/// <reference types="react-scripts" />${os.EOL}`
+    );
+  }
 }
 
 module.exports = verifyTypeScriptSetup;