code coverage with expand_assets=false

Hi,

we're trying to get code coverage via istanbul working with expand_assets=false. We're getting the following error message (coverage object is null, when using expand_assets=true, coverage object is defined):

$ bundle exec rake teaspoon

** Invoke teaspoon (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute teaspoon
Starting the Teaspoon server...
Teaspoon running default suite at http://127.0.0.1:63634/teaspoon/default
..

Finished in 2.28000 seconds
2 examples, 0 failures

Unable to generate text-summary coverage report:
/usr/local/lib/node_modules/istanbul/lib/collector.js:69
        Object.keys(coverage).forEach(function (key) {
               ^

TypeError: Cannot convert undefined or null to object
    at Function.keys (native)
    at Object.Collector.add (/usr/local/lib/node_modules/istanbul/lib/collector.js:69:16)
    at /usr/local/lib/node_modules/istanbul/lib/command/report.js:111:27
    at Array.forEach (native)
    at /usr/local/lib/node_modules/istanbul/lib/command/report.js:109:19
    at /usr/local/lib/node_modules/istanbul/lib/util/file-matcher.js:39:20
    at Object.next (/usr/local/lib/node_modules/istanbul/node_modules/fileset/lib/fileset.js:43:14)
    at emitOne (events.js:77:13)
    at Fileset.emit (events.js:169:7)
    at Fileset.Glob._finish (/usr/local/lib/node_modules/istanbul/node_modules/fileset/node_modules/glob/glob.js:172:8)

versions:

$ teaspoon --version
1.1.1

$ ruby -v
ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-darwin14]

teaspoon_env:

Teaspoon.configure do |config|
  config.mount_at = "/teaspoon"
  config.root = nil
  config.asset_paths = ["spec/javascripts", "spec/javascripts/stylesheets"]
  config.fixture_paths = ["spec/javascripts/fixtures"]

  config.suite do |suite|
    suite.use_framework :jasmine, "2.3.4"
    suite.matcher = "{spec/javascripts/desktop}/**/*_spec.{js,js.coffee,coffee,js.erb}"
    suite.helper = "spec_helper_desktop"
    suite.boot_partial = "boot"
    suite.body_partial = "body"
    suite.expand_assets = false
  end

  config.suite :mobile do |suite|
    suite.matcher = "{spec/javascripts/mobile}/**/*_spec.{js,js.coffee,coffee,js.erb}"
    suite.helper = "spec_helper_mobile"
  end

  config.use_coverage = true

  config.coverage do |coverage|
    coverage.reports = ["text-summary", 'html']
    coverage.ignore = [%r{.rvm}, %r{/lib/ruby/gems/}, %r{/vendor/assets/}, %r{/support/}, %r{/(.+)_helper.}, %r{/app/assets/javascripts/(.+)/vendor}, %r{/app/assets/javascripts/(.+)/vendor}, %r{/vendor/bundle}, %r{/spec/javascripts}]
    coverage.ignore = coverage.ignore.reject { |matcher| matcher.match('/spec_helper*.') }
  end
end

spec/javascripts/spec_helper_desktop.js

// Teaspoon includes some support files, but you can use anything from your own support path too.
// require support/jasmine-jquery-1.7.0
// require support/jasmine-jquery-2.0.0
// require support/jasmine-jquery-2.1.0
// require support/sinon
//
// PhantomJS (Teaspoons default driver) doesn't have support for Function.prototype.bind, which has caused confusion.
// Use this polyfill to avoid the confusion.
//= require support/phantomjs-shims
//= require support/factories
//= require support/promise
//= require desktop/application
//

spec/javascripts/spec_helper_mobile.js

// Teaspoon includes some support files, but you can use anything from your own support path too.
// require support/jasmine-jquery-1.7.0
// require support/jasmine-jquery-2.0.0
// require support/jasmine-jquery-2.1.0
// require support/sinon
//
// PhantomJS (Teaspoons default driver) doesn't have support for Function.prototype.bind, which has caused confusion.
// Use this polyfill to avoid the confusion.
//= require support/phantomjs-shims
//= require support/factories
//= require support/promise
//= require mobile/application
//

example spec: spec/javascripts/desktop/link_spec.js

describe('Link', function() {
    'use strict';
    it('should be available in global namespace', function() {
        expect(Link).toBeDefined();
    });
});

Is there an error within our config or is this an issue?

jejacks0n / teaspoon

code coverage with expand_assets=false #436