Refactor ConfigurationParser specs

- Add test for passing in CLI options
- Rework the tests to not stub the SUT
- Don't use `let` because Caleb hates it.

spec/configuration_parser_spec.rb

@@ -1,30 +1,74 @@
 require 'spec_helper'
 
 describe Liftoff::ConfigurationParser do
-  describe "#project_configuration" do
-    let (:parser) { described_class.new }
+  describe '#project_configuration' do
+    it 'returns a hash evaluated from the local, user, default, and command line configurations' do
+      stub_and_override(:user, :local)
 
-    before do
-      parser.stub(:default_configuration) { { :pasta => 1, :beer => 1, :cheese_cake => 1 } }
-      parser.stub(:user_configuration) { { :pasta => 0, :pizza => 2 } }
-      parser.stub(:local_configuration) { { :beer => 2, :cheese_cake => 2 } }
+      parser = Liftoff::ConfigurationParser.new(cli_options)
+
+      expected = { :pasta => 0, :pizza => 2, :beer => 0, :cheese_cake => 2 , :whiskey => 1 }
+      expect(parser.project_configuration).to eq expected
     end
 
-    it "returns a set of project_configuration evaluated starting form pwd, falling back to home, falling back to defaults" do
-      expected_project_configuration = { :pasta => 0, :pizza => 2, :beer => 2, :cheese_cake => 2 }
-      parser.project_configuration.should eq(expected_project_configuration)
+    it 'falls back to the user config if no command line options were passed' do
+      stub_and_override(:user, :local)
+
+      parser = Liftoff::ConfigurationParser.new({})
+
+      expected = { :pasta => 0, :beer => 2, :pizza => 2, :cheese_cake => 2 }
+      expect(parser.project_configuration).to eq expected
     end
 
-    it "doesn't break in case the pwd project_configuration are missing" do
-      parser.stub(:local_configuration) { {} }
-      expected_project_configuration = { :pasta => 0, :pizza => 2, :beer => 1, :cheese_cake => 1 }
-      parser.project_configuration.should eq(expected_project_configuration)
+    it 'falls back to the user configuration if the local configuration is missing' do
+      stub_and_override(:user)
+
+      parser = Liftoff::ConfigurationParser.new(cli_options)
+
+      expected = { :pasta => 0, :pizza => 2, :beer => 0, :cheese_cake => 1 , :whiskey => 1}
+      expect(parser.project_configuration).to eq expected
     end
 
-    it "doesn't break in case the home project_configuration are missing" do
-      parser.stub(:user_configuration) { {} }
-      expected_project_configuration = { :pasta => 1, :beer => 2, :cheese_cake => 2 }
+    it 'falls back to the default if the user configuration is missing' do
+      stub_and_override(:local)
+
+      parser = Liftoff::ConfigurationParser.new(cli_options)
+
+      expected_project_configuration = { :pasta => 1, :beer => 0, :cheese_cake => 2 , :whiskey => 1 }
       parser.project_configuration.should eq(expected_project_configuration)
     end
   end
+
+  def stub_and_override(*overrides)
+    stub_defaults
+    stub_user(overrides.include?(:user))
+    stub_local(overrides.include?(:local))
+  end
+
+  def stub_defaults
+    liftoffrc_path = File.expand_path('../../defaults/liftoffrc', __FILE__)
+    default_configuration = { :pasta => 1, :beer => 1, :cheese_cake => 1 }
+    stub_path(liftoffrc_path, default_configuration, true)
+  end
+
+  def stub_user(exists)
+    liftoffrc_path = File.join(ENV['HOME'], '.liftoffrc')
+    user_configuration = { :pasta => 0, :pizza => 2 }
+    stub_path(liftoffrc_path, user_configuration, exists)
+  end
+
+  def stub_local(exists)
+    liftoffrc_path = File.join(Dir.pwd, '.liftoffrc')
+    local_configuration = { :beer => 2, :cheese_cake => 2 }
+    stub_path(liftoffrc_path, local_configuration, exists)
+  end
+
+  def stub_path(path, result, exists)
+    File.stub(:exists?).with(path) { exists }
+    YAML.stub(:load_file).with(path) { result }
+  end
+
+  def cli_options
+    { :beer => 0, :whiskey => 1 }
+  end
 end