fixed issue which caused always using yarn as the packager

[feat] add support for Yarn + inheriting exec process

README.md

@@ -2,14 +2,17 @@
 
 Clean and minimalist React Native template for a quick start with TypeScript.
 
+[![Header](https://cdn-images-1.medium.com/max/500/1*E9RnPOATuhjuNrlFkv5oSg.jpeg)](https://medium.com/@emin93/react-native-typescript-b965059109d3)
+
 This template can be used with the React Native CLI, which means it doesn't mess with the platform specific files. Instead of including a lot of dependencies, my aim when creating this template was to provide a very easy and minimalist way to start your React Native project with TypeScript. Of course you can always include other dependencies as you need them.
 
 ## :star: Features
 
--   Seamless integration with the React Native CLI
--   Always latest dependencies
--   React Native TypeScript transformer directly integrated into the packager! (No separate process for TSC)
--   Unit testing in TypeScript with Jest
+-   Seamless integration with the React Native CLI! :sparkles:
+-   Consistent with the default React Native template (no additional stuff)
+-   React Native TypeScript transformer directly integrated into the packager (no separate process for `tsc`)
+-   Unit testing in TypeScript with TS Jest
+-   Always latest dependencies :raised_hands:
 
 ## :arrow_forward: Quick Start
 
@@ -23,10 +26,10 @@ node setup.js
 
 ### What is included in this template?
 
-- [TypeScript](https://github.com/Microsoft/TypeScript)
-- [React Native TypeScript transformer](https://github.com/ds300/react-native-typescript-transformer)
-- [Type definitions for React & React Native](https://github.com/DefinitelyTyped/DefinitelyTyped)
-- [TS Jest](https://github.com/kulshekhar/ts-jest)
+-   [TypeScript](https://github.com/Microsoft/TypeScript)
+-   [React Native TypeScript transformer](https://github.com/ds300/react-native-typescript-transformer)
+-   [Type definitions for React & React Native](https://github.com/DefinitelyTyped/DefinitelyTyped)
+-   [TS Jest](https://github.com/kulshekhar/ts-jest)
 
 This template always uses the latest versions of the dependencies at the time when the setup script (`node setup.js`) is being executed. This means you don't have to worry about old versions.
 
@@ -40,6 +43,10 @@ The React Native CLI supports automatic installation of production dependencies
 
 The React Native CLI will do everything just as without a template and afterwards overwrite the files with the ones from this template. This means you don't have to worry about incompatibility issues with later React Native upgrades.
 
+## :globe_with_meridians: Links
+
+-   ["Using React Native with TypeScript just became simple" on Medium](https://medium.com/@emin93/react-native-typescript-b965059109d3)
+
 ## :computer: Contributing
 
 Contributions are very welcome. Please try to stay consistent with the other files I've created.

index.ts

@@ -1,4 +0,0 @@
-import { AppRegistry } from 'react-native';
-import App from './App';
-
-AppRegistry.registerComponent('HelloWorld', () => App);

package.json

@@ -12,7 +12,6 @@
     "keywords": [
         "react-native",
         "typescript",
-        "tslint",
         "jest",
         "template",
         "boilerplate"

setup.js

@@ -8,16 +8,32 @@ const devDependencies = require('./devDependencies.json');
 
 const deleteFile = (fileName) => fs.unlinkSync(path.join(process.cwd(), fileName));
 const writeFile = (fileName, data) => fs.writeFileSync(path.join(process.cwd(), fileName), data);
+const isYarnAvailable = () => {
+    try {
+        execSync('yarnpkg --version', { stdio: 'ignore' });
+        return true;
+    } catch (e) {
+        return false;
+    }
+}
 
-console.log('🔄 Please wait...');
+const packager = isYarnAvailable() ? 'yarn' : 'npm';
+const execOptions = { stdio: 'inherit' };
+
+console.log('\n🔄 Please wait...\n');
 
 packageJson.scripts.start = `${packageJson.scripts.start} --config ../../../../rn-cli.config.js`;
 packageJson.jest = Object.assign(packageJson.jest, jestJson);
 writeFile('package.json', JSON.stringify(packageJson, null, 2));
 
-execSync(`npm i ${devDependencies.join(' ')} --save-dev --save-exact`);
+console.log(`\n📦 Installing dependencies with ${packager}...\n`);
+
+if (packager === 'yarn') {
+    execSync(`yarn add ${devDependencies.join(' ')} --dev --exact`, execOptions);
+} else {
+    execSync(`npm i ${devDependencies.join(' ')} --save-dev --save-exact`, execOptions);
+}
 
-deleteFile('index.js');
 deleteFile('App.js');
 deleteFile('__tests__/App.js');
 deleteFile('.flowconfig');
@@ -27,4 +43,4 @@ deleteFile('README.md');
 deleteFile('LICENSE');
 deleteFile('setup.js');
 
-console.log('✅ Setup completed! You can now start with: npm start');
+console.log(`\n✅ Setup completed! You can now start with: ${packager} start\n`);