Remove test packages from production bundles

[leosoaivan]

Because:

An analysis of our javascript packs/bundle showed test packages being included, including @testing-library and pretty-format.

Presently, it doesn't appear as though there is an option in webpacker.yml for an exclude path/pattern (see here). Therefore, it appears as though webpacker is creating an abstract syntax tree that includes all JS files in app/javascript/, including the component test files. This would explain why the final bundle includes the 2 aforementioned packages, and not Jest.

This reduces our bundle size by about 200KB.

This commit

• Installs webpack-bundle-analyzer and creates an npm script for it
• Ignores files under any directories that match **/__tests__/*

Checklist

• You have read The Odin Projects Contributing Guide?
• You have verified the tests and linters all pass against your changes?
• You have included automated tests for your changes where applicable?

[leosoaivan]

ok to test

[KevinMulhern]

Hey @leosoaivan, thanks for digging into this. It looks like something with webpack-bundle-analyzer is breaking the review app build.

snippet from the stacktrace:

 Compiling...
       Compilation failed:
       /tmp/build_351b75c3/node_modules/webpack-cli/bin/cli.js:93
       				throw err;
       				^
       
       Error: Cannot find module 'webpack-bundle-analyzer'
       Require stack:

I've sent you an invite to the Heroku pipeline the review app's are built on so you can have a play with it.

[KevinMulhern]

ahh It might be this, do we only want the bundle-analyzer in development mode since production will ignore the dev dependencies?

I think moving all the webpack-bundle-analyzer stuff to config/webpack/development.js will fix the build issue if thats the case.

[ChargrilledChook]

I'm guessing this is going to be redundant soon with the shakapacker switch - #3031

Is this something we should still have a look at?

[KevinMulhern]

Closing due to inactivity