How to decrease prod bundle size?

Question

I have a simple app, initialized by angular-cli.

It display some pages relative to 3 routes. I have 3 components. On one of this page I use lodash

Answer 1

The following solution assumes you are serving your dist/ folder using nodejs. Please use the following app.js in root level

const express = require('express'),http = require('http'),path = require('path'),compression = require('compression');

const app = express();

app.use(express.static(path.join(__dirname, 'dist')));
app.use(compression()) //compressing dist folder 
app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'dist/index.html'));
})

const port = process.env.PORT || '4201';
app.set('port', port);

const server = http.createServer(app);
server.listen(port, () => console.log('Running at port ' + port))

Make sure you install dependencies;

npm install compression --save
npm install express --save;

Now build the app

ng build --prod --build-optimizer

If you want to further compress the build say reduce 300kb(approx) from , then follow the below process;

Create a folder called vendor inside the src folder and inside vendor folder create a file rxjs.ts and paste the below code in it;

export {Subject} from 'rxjs/Subject';
export {Observable} from 'rxjs/Observable';
export {Subscription} from 'rxjs/Subscription';

And then add the follwing in the tsconfig.json file in your angular-cli application. Then in the compilerOptions , add the following json;

"paths": {
      "rxjs": [
        "./vendor/rxjs.ts"
      ]
    }

This will make your build size way too smaller. In my project I reduced the size from 11mb to 1mb. Hope it helps