Testem config file

testem.json

{
  "framework": [
    "jasmine"
  ],
  "launch_in_dev": [
    "PhantomJS"
  ],
  "launch_in_ci": [
    "PhantomJS"
  ],
  "src_files": [
    "spec/coffeescripts/*_spec.coffee",
    "spec/coffeescripts/**/*_spec.coffee"
  ],
  "serve_files": [
    "app/js/*.js",
    "app/js/**/*.js",
    "spec/javascripts/*_spec.js",
    "spec/javascripts/**/*_spec.js"
  ],
  "before_tests": [
    "coffee -o spec/javascripts/ -c spec/coffeescripts/"
  ],
  "on_exit": [
    "find spec/javascripts/ -iname '*_spec.js' | xargs rm -rfv"
  ]
}

testem.yaml

framework: 
  - "jasmine"
launch_in_dev: 
  - "PhantomJS"
launch_in_ci: 
  - "PhantomJS"
src_files:
  - "spec/coffeescripts/*_spec.coffee"
  - "spec/coffeescripts/**/*_spec.coffee"
serve_files:
  - "app/js/*.js"
  - "app/js/**/*.js"
  - "spec/javascripts/*_spec.js"
  - "spec/javascripts/**/*_spec.js"
before_tests: 
  - "coffee -o spec/javascripts/ -c spec/coffeescripts/"
on_exit: 
  - "find spec/javascripts/ -iname '*_spec.js' | xargs rm -rfv"