Sprockets/Rails: Find all files Sprockets knows how to compile

Question

For Konacha, a Rails engine for testing Rails apps, we need a way to find all files that Sprockets can compile to JavaScript. Right now we use something like ``` Dir['spec/javascripts/**/*_spec.*'] ``` but this picks up `.bak`, `.orig`, and other backup files. Can Sprockets tell us somehow whether it knows how to compile a file, so that backup files would be automatically excluded? `content_type_of` doesn't help: ``` Rails.application.assets.content_type_of('test/javascripts/foo.js.bak') => "application/javascript" ```

Accepted Answer

You can iterate through all the files in a `Sprockets::Environment`'s load path using the `each_file` method:

```
Rails.application.assets.each_file { |pathname| ... }
```

The block will be invoked with a `Pathname` instance for the fully expanded path of each file in the load path.

`each_file` returns an `Enumerator`, so you can skip the block and get an array with `to_a`, or call `include?` on it. For example, to check whether a file is in the load path:

```
assets = Rails.application.assets
pathname1 = Pathname.new("test/javascripts/foo.js").expand_path
pathname2 = Pathname.new("test/javascripts/foo.js.bak").expand_path
assets.each_file.include?(pathname1) # => true
assets.each_file.include?(pathname2) # => false
```

Sprockets/Rails: Find all files Sprockets knows how to compile

Solution

Problem