title: angular 2 npm start duplicate identifiers error
body: <p>I am getting the following errors:</p>
  
  <p><img src="https://i.stack.imgur.com/JS8FQ.png" alt="this is the error "></p>
  
  <p>When I run  the command (npm-install) in windows cmd it works fine, but when I used the command npm start it gives me an error "duplicate identifiers" in ts files.</p>
  
  <p>I tried to remove node-modules and then I run the command npm install the problem persist.</p>
  
  <p>This is my tsconfig.json:</p>
  
  <pre><code>{
    "compilerOptions": {
      "target": "es5",
      "module": "commonjs",
      "moduleResolution": "node",
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "sourceMap": true,
      "baseUrl": "./src/main/webapp",
      "paths": {
      },
      "lib": [
        "es2015",
        "dom"
      ],
      "typeRoots": [
        "node_modules/@types"
      ]
    },
    "exclude": [
      "node_modules",
      "target"
    ],
    "awesomeTypescriptLoaderOptions": {
      "forkChecker": true,
      "useWebpackText": true
    },
    "compileOnSave": false,
    "buildOnSave": false,
    "atom": {
      "rewriteTsconfig": false
    }
  }
  </code></pre>