title: How check if Vue is in development mode?
body: <p>When I run my Vue app, the console shows:</p>
  
  <pre><code>You are running Vue in development mode.
  Make sure to turn on production mode when deploying for production.
  See more tips at https://vuejs.org/guide/deployment.html
  </code></pre>
  
  <p>So now I want to check if Vue is in development from inside my templates by using:</p>
  
  <pre><code>console.log("mode is " + process.env.NODE_ENV)
  </code></pre>
  
  <p>But that only logs <code>undefined</code>
  Is there a different way to find the NODE_ENV in Vue?</p>
  
  <p>My webpack config has this part:</p>
  
  <pre><code>if (process.env.NODE_ENV === 'production') {
    module.exports.devtool = '#source-map'
    // http://vue-loader.vuejs.org/en/workflow/production.html
    module.exports.plugins = (module.exports.plugins || []).concat([
      new webpack.DefinePlugin({
        'process.env': {
          NODE_ENV: '"production"'
        }
      }),
      new webpack.optimize.UglifyJsPlugin({
        sourceMap: true,
        compress: {
          warnings: false
        }
      }),
      new webpack.LoaderOptionsPlugin({
        minimize: true
      })
    ])
  }
  </code></pre>
  
  <p>Perhaps relevant: I use typescript, so I included this type declaration:</p>
  
  <pre><code>declare var process: {
      env: {
          NODE_ENV: string
      }
  }
  </code></pre>