Revert the extension path to not expand to sub-directories to stop OOM

[robdimarco]

After upgrading to 2.0, I was consistently running out of RAM when trying to run webpack.

After some digging, I came across a comment on the webpack project that helped shed some light.

webpack/webpack#1914 (comment)

It seems that in PR 201 (#201), the extensionGlob
was changed from *{${paths.extensions.join(',')}}* to **/*{${paths.extensions.join(',')}}*

This change removes the **/ in the extension and fixes my OOM issue.

I am not sure about the ramifications for allowing pack files in subdirectories
(the original intent of the PR that introduced the change). Maybe we need a comment or a
flag when generating the configuration that will set it one way or the other?

[gauravtiwari]

@robdimarco What files you have under packs or whatever folder you are using for entries/packs?

[robdimarco]

I have 5 files directly in app/javascript/packs and 131 files all told if you include files in subdirectories. This includes Jest tests (in __tests__ subdirectories).

[guilleiguaran]

@joerodrig this looks similar to the issue you found the last week.

[guilleiguaran]

I guess the official reply for this is that this is totally expected since we expect to have in app/javascripts/packs only the 'packs' that are equivalent to webpack entry points, anything else should be in app/javascripts but outside of packs, that's just the convention that we have adopted for this.

[robdimarco]

OK, that works for me. Thanks.

[gauravtiwari]

Perhaps we make this more clear in README 👍

[marcelkooi]

@robdimarco I'm curious to know if you've run into any issues with this change? We're looking to make this change for our app as well and have noticed that it reduces our deployment time substantially, but would like to make sure it doesn't have any downstream effects

[robdimarco]

@Marz0 worked great for us. No side-effects.