Adds a --use-pnp option

Author: Maël Nison

packages/create-react-app/createReactApp.js

@@ -76,6 +76,7 @@ const program = new commander.Command(packageJson.name)
     'use a non-standard version of react-scripts'
   )
   .option('--use-npm')
+  .option('--use-pnp')
   .allowUnknownOption()
   .on('--help', () => {
     console.log(`    Only ${chalk.green('<project-directory>')} is required.`);
@@ -178,10 +179,11 @@ createApp(
   program.verbose,
   program.scriptsVersion,
   program.useNpm,
+  program.usePnp,
   hiddenProgram.internalTestingTemplate
 );
 
-function createApp(name, verbose, version, useNpm, template) {
+function createApp(name, verbose, version, useNpm, usePnp, template) {
   const root = path.resolve(name);
   const appName = path.basename(root);
 
@@ -241,7 +243,16 @@ function createApp(name, verbose, version, useNpm, template) {
       version = '[email protected]';
     }
   }
-  run(root, appName, version, verbose, originalDirectory, template, useYarn);
+  run(
+    root,
+    appName,
+    version,
+    verbose,
+    originalDirectory,
+    template,
+    useYarn,
+    usePnp
+  );
 }
 
 function shouldUseYarn() {
@@ -253,7 +264,7 @@ function shouldUseYarn() {
   }
 }
 
-function install(root, useYarn, dependencies, verbose, isOnline) {
+function install(root, useYarn, usePnp, dependencies, verbose, isOnline) {
   return new Promise((resolve, reject) => {
     let command;
     let args;
@@ -263,6 +274,9 @@ function install(root, useYarn, dependencies, verbose, isOnline) {
       if (!isOnline) {
         args.push('--offline');
       }
+      if (usePnp) {
+        args.push('--enable-pnp');
+      }
       [].push.apply(args, dependencies);
 
       // Explicitly set cwd() to work around issues like
@@ -287,6 +301,12 @@ function install(root, useYarn, dependencies, verbose, isOnline) {
         '--loglevel',
         'error',
       ].concat(dependencies);
+
+      if (usePnp) {
+        console.log(chalk.yellow("NPM doesn't support PnP."));
+        console.log(chalk.yellow('Falling back to the regular installs.'));
+        console.log();
+      }
     }
 
     if (verbose) {
@@ -313,7 +333,8 @@ function run(
   verbose,
   originalDirectory,
   template,
-  useYarn
+  useYarn,
+  usePnp
 ) {
   const packageToInstall = getInstallPackage(version, originalDirectory);
   const allDependencies = ['react', 'react-dom', packageToInstall];
@@ -336,9 +357,14 @@ function run(
       );
       console.log();
 
-      return install(root, useYarn, allDependencies, verbose, isOnline).then(
-        () => packageName
-      );
+      return install(
+        root,
+        useYarn,
+        usePnp,
+        allDependencies,
+        verbose,
+        isOnline
+      ).then(() => packageName);
     })
     .then(async packageName => {
       checkNodeVersion(packageName);

tasks/e2e-installs.sh

@@ -233,8 +233,7 @@ yarn start --smoke-test
 # Test when PnP is enabled
 # ******************************************************************************
 cd "$temp_app_path"
-echo $OSTYPE
-YARN_PLUGNPLAY_OVERRIDE=1 npx create-react-app test-app-pnp
+npx create-react-app test-app-pnp --use-pnp
 cd test-app-pnp
 ! exists node_modules
 exists .pnp.js