Issues with tree-shaking in v3 beta

Intended outcome:

I would expect these bundles to be roughly the same size:

import {Observable} from 'apollo-boost'
console.log(Observable)

and:

import {Observable} from '@apollo/client'
console.log(Observable)

Actual outcome:

The apollo-boost bundle is 7.6 KiB, whereas the @apollo/client bundle is 94.2 KiB.

How to reproduce the issue:

Compare this branch to this branch. To produce the bundle size measurements, check out either branch and run npm run build.

Versions

For the apollo-boost bundle:

  System:
    OS: macOS Mojave 10.14.6
  Binaries:
    Node: 12.13.1 - ~/.config/nvm/12.13.1/bin/node
    npm: 6.13.4 - ~/.config/nvm/12.13.1/bin/npm
  Browsers:
    Chrome: 79.0.3945.79
    Firefox: 69.0.2
    Safari: 13.0.4
  npmPackages:
    apollo-boost: ^0.4.7 => 0.4.7 

The @apollo/client one is the same except:

  npmPackages:
    @apollo/client: 3.0.0-beta.34 => 3.0.0-beta.34

[benjamn]

Thanks for all the detailed info @miqdadfwz! We will dig into this before the Apollo Client v3.4 launch is finalized (though probably during the Release Candidate phase, since improving tree-shakeability should be relatively a transparent optimization, not a change in functionality).

[miqdadfwz]

Well I’m using the same webpack configuration (webpack v4), but ended up with significantly larger size comparing with former AC version.

Here is AC3 result using webpack bundle analyzer, it takes 39kb gzip along with graphql dependency. I’m afraid the tree shaking is partially not working here.

And here for AC2 with same chunks combination and other AC2 dependecies such as apollo-link-* and @apollo/react-hooks, it only takes 26kb.