There are lots of moving parts for this question so I will post everything. I am running npm run build and I get the following:

Here is my build script in package.json file:

"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build":"browserify -d app/scripts/src/main.js -o app/scripts/dist/main.js" 
  },
  "browserify":{
    "transform":[
      "babelify",{"presets":["es2015"],"sourceMap":true}
    ]
  },

app.js:

class ChatApp {
  constructor() {
    console.log("Hello World")
  }
}
 export default ChatApp 

main.js:

import ChatApp from './app'
new ChatApp()

Node version: 6.9.4

Browserify version: 14.3.0

UPDATE:

I updated it and still same result.

  "build":"browserify app/scripts/src/main.js -d -o app/scripts/dist/main.js"

This also does not work and gives the same error:

"build":"browserify app/scripts/src/main.js > app/scripts/dist/main.js -d -o"

Also this same result:

"build":"browserify app/scripts/src/main.js > app/scripts/dist/main.js"

UPDATE: Running only the Browserify command from terminal

browserify app/scripts/src/main.js app/scripts/dist/main.js -d -o 
TypeError: Path must be a string.
    at resolve (/usr/local/lib/node_modules/browserify/node_modules/resolve/lib/async.js:15:19)
    at nr (/usr/local/lib/node_modules/browserify/node_modules/module-deps/index.js:282:24)
    at /usr/local/lib/node_modules/browserify/node_modules/resolve/lib/async.js:17:13
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)