Fix: Init duplication

packages/cli/src/commands/init/__tests__/validate.test.js

@@ -2,6 +2,7 @@
 import {validateProjectName} from '../validate';
 import InvalidNameError from '../errors/InvalidNameError';
 import ReservedNameError from '../errors/ReservedNameError';
+import HelloWorldError from '../errors/HelloWorldError';
 
 test.each(['projectName', 'ProjectName', 'project_name'])(
   "'%s' project name should be valid",
@@ -23,6 +24,10 @@ test.each([
     name: 'react',
     error: ReservedNameError,
   },
+  {
+    name: 'helloworld_test',
+    error: HelloWorldError,
+  },
 ])("'%s' is invalid name", ({name, error}: {name: string, error: Error}) => {
   expect(() => validateProjectName(name)).toThrowError(error);
 });

packages/cli/src/commands/init/errors/HelloWorldError.js

@@ -0,0 +1,8 @@
+// @flow
+export default class HelloWorldError extends Error {
+  constructor() {
+    super(
+      'Project name shouldn\'t contain "HelloWorld" name in it, because it is CLI\'s default placeholder name.',
+    );
+  }
+}

packages/cli/src/commands/init/validate.js

@@ -1,6 +1,7 @@
 // @flow
 import InvalidNameError from './errors/InvalidNameError';
 import ReservedNameError from './errors/ReservedNameError';
+import HelloWorldError from './errors/HelloWorldError';
 
 const NAME_REGEX = /^[$A-Z_][0-9A-Z_$]*$/i;
 
@@ -12,4 +13,8 @@ export function validateProjectName(name: string) {
   if (name === 'React' || name === 'react') {
     throw new ReservedNameError();
   }
+
+  if (name.match(/helloworld/gi)) {
+    throw new HelloWorldError();
+  }
 }