Compiler fails silently if no output file is selected

[changemewtf]

Create this folder structure:

.
|-- Gemfile
|-- Guardfile
|-- application.coffee
`-- static/

With this Guardfile:

guard 'coffeescript', input: '', output: 'static' do
  watch 'application.coffee'
end

Guard will output Successfully generated static/application.js when application.coffee is changed, but no file will be created.

This is due to the detect_nested_directories method using patterns.product(files) to generate output locations when :shallow is set to false (the default).

Perhaps this error message would be appropriate:

ArgumentError: Ambiguous output directory for application.js. Try setting :shallow to true.

[e2]

Thanks. Could you create a PR for this?

[changemewtf]

I'm not sure where the spec for it should go, nor exactly how to manipulate the inputs to faithfully recreate the error conditions. I'm assuming the integration test is the right place, but how much is being faked out? The test suite in general assumes non-pwd input directory.

[e2]

Yeah, it's not beautiful, but I'll be glad to help you as much as I can.

Since the fix is in the detect_nested_directories method I guess, it should be in the runner_spec.rb. It's about testing an edge case for a method, so don't worry about integration testing.

Maybe here:

guard-coffeescript/spec/guard/coffeescript/runner_spec.rb

Line 122 in 5272ccd

context 'with the :shallow option set to false' do

The specs aren't great, so just copy a similar block, set the parameters to the ones you have, and just reproduce the problem for now.

If you're unsure about the setting up the conditions properly, just output values to the screen while having the problem, and check if you get the same values while running the spec.