Check for multiple project names when initializing (facebook#6080)

packages/create-react-app/createReactApp.js

@@ -143,11 +143,24 @@ if (program.info) {
     .then(console.log);
 }
 
-if (typeof projectName === 'undefined') {
-  console.error('Please specify the project directory:');
-  console.log(
-    `  ${chalk.cyan(program.name())} ${chalk.green('<project-directory>')}`
-  );
+const hasMultipleProjectNameArgs =
+  process.argv[3] && !process.argv[3].startsWith('-');
+if (typeof projectName === 'undefined' || hasMultipleProjectNameArgs) {
+  console.log();
+  if (hasMultipleProjectNameArgs) {
+    console.error(
+      `You have provided more than one argument for ${chalk.green(
+        '<project-directory>'
+      )}.`
+    );
+    console.log();
+    console.log('Please specify only one project directory, without spaces.');
+  } else {
+    console.error('Please specify the project directory:');
+    console.log(
+      `  ${chalk.cyan(program.name())} ${chalk.green('<project-directory>')}`
+    );
+  }
   console.log();
   console.log('For example:');
   console.log(`  ${chalk.cyan(program.name())} ${chalk.green('my-react-app')}`);