Merge pull request #486 from BBC-News/imports

Adds 'Imports' functionality

lib/wraith/helpers/utilities.rb

@@ -1,5 +1,11 @@
 require "wraith/helpers/custom_exceptions"
 
+def absolute_path_of_dir(filepath)
+  path_parts = filepath.split('/')
+  path_to_dir = path_parts.first path_parts.size - 1
+  path_to_dir.join('/')
+end
+
 def convert_to_absolute(filepath)
   if !filepath
     "false"

lib/wraith/wraith.rb

@@ -7,11 +7,21 @@ class Wraith::Wraith
   attr_accessor :config
 
   def initialize(config, yaml_passed = false)
-    @config = yaml_passed ? config : open_config_file(config)
+    if yaml_passed
+      @config = config
+    else
+      filepath = determine_config_path config
+      @config = YAML.load_file filepath
+    end
+
+    if @config['imports']
+      @config = apply_imported_config(@config['imports'], @config)
+    end
+
     logger.level = verbose ? Logger::DEBUG : Logger::INFO
   end
 
-  def open_config_file(config_name)
+  def determine_config_path(config_name)
     possible_filenames = [
       config_name,
       "#{config_name}.yml",
@@ -22,13 +32,24 @@ def open_config_file(config_name)
 
     possible_filenames.each do |filepath|
       if File.exist?(filepath)
-        config = File.open filepath
-        return YAML.load config
+        @config_dir = absolute_path_of_dir(convert_to_absolute filepath)
+        return convert_to_absolute filepath
       end
     end
+
     fail ConfigFileDoesNotExistError, "unable to find config \"#{config_name}\""
   end
 
+  def apply_imported_config(config_to_import, config)
+    path_to_config = "#{@config_dir}/#{config_to_import}"
+    if File.exist?(path_to_config)
+      yaml = YAML.load_file path_to_config
+      return yaml.merge(config)
+    end
+
+    fail ConfigFileDoesNotExistError, "unable to find referenced imported config \"#{config_name}\""
+  end
+
   def directory
     # Legacy support for those using array configs
     @config["directory"].is_a?(Array) ? @config["directory"].first : @config["directory"]

spec/config_spec.rb

@@ -16,6 +16,16 @@
     it "contains shot options" do
       expect(wraith.config).to include "directory" => "shots"
     end
+
+    it "should be able to import other configs" do
+      config_name = get_path_relative_to __FILE__, "./configs/test_config--imports.yaml"
+      wraith = Wraith::Wraith.new(config_name)
+
+      # retain the imported config settings
+      expect(wraith.paths).to eq("home" => "/", "uk_index" => "/uk")
+      # ...but override the imported config in places
+      expect(wraith.widths).to eq [1337]
+    end
   end
 
   describe "When creating a wraith worker" do

spec/configs/test_config--imports.yaml

@@ -0,0 +1,4 @@
+imports: 'test_config--phantom.yaml'
+
+screen_widths:
+  - 1337