Source-map refresh question

[merqlove]

How to setup it right for guaranteed source-map refresh?

Currently i have new branch of Rails 4.2 with Sprockets 4.0 beta2.

TL;DR
Repo with reproduce:
https://github.com/merqlove/sprockets4-source-map-bug

Added manifest file with source like this:

// assets/config/manifest.js
//= link_tree ../images
//= link_directory ../javascripts .js
//= link_directory ../stylesheets .scss

//= link application.js
//= link application.css

Also i have root coffeescript file:

# assets/javascripts/application.coffee

#= require web/index

And web folder index file:

# assets/javascripts/web/index.coffee
#= require_self
...
#= require_tree ./broadcasts
...
# some code

First time SourceMap processor generates right version of the map.
But, if i did some changes in the content, for example its child file with coffeescript source in ./broadcasts, content of application....js is changing, for example i'm added console('LALALA') but SourceMap not refreshing, always same source-map file with same fingerprint.
4 times i've looks to the end of application....js, and 4 times i found:

//# sourceMappingURL=application.js-64eb1dee0f03a6038c4dd3bd9f77a25f7b5c05095344c19b5800bba7289b443e.map
//# sourceMappingURL=application.js-64eb1dee0f03a6038c4dd3bd9f77a25f7b5c05095344c19b5800bba7289b443e.map
//# sourceMappingURL=application.js-64eb1dee0f03a6038c4dd3bd9f77a25f7b5c05095344c19b5800bba7289b443e.map
//# sourceMappingURL=application.js-64eb1dee0f03a6038c4dd3bd9f77a25f7b5c05095344c19b5800bba7289b443e.map

Same picture also i've seen with master branch of current repo.

[merqlove]

Seems that something with cache.
Because i see map changes in coffee processor.

[merqlove]

So here screenshot and repo with reproduce:
https://github.com/merqlove/sprockets4-source-map-bug

[Strech]

I will try to debug and fix it (I hope, that I can find a solution or point to the root cause)

[merqlove]

@Strech
Example, how SourceMap can look out from Webpack:

[Strech]

@merqlove I've succeeded with reproducible failure in tests. Hopefully, I will nail this issue 😲

[schneems]

Thanks for this repro case, it made verifying the fix way easier. Thank you all for your detailed bug report and for fix.

[merqlove]

Thanks! Seems it works. Tested on staging project.