Change the default behavior for arrays from merging to overwriting (f…

…ixes rubyconfig#12)

README.md

@@ -259,6 +259,46 @@ It won't work with arrays, though.
 
 To upload your local values to Heroku you could ran `bundle exec rake rails_config:heroku`.
 
+## Overwriting or Merging Arrays
+
+We changed the default behavior for arrays from merging to overwriting. Eg:
+
+settings.yml
+
+```yaml
+some_array:
+- 1
+- 2
+```
+
+settings.local.yml
+
+```yaml
+some_array:
+- 3
+- 4
+```
+
+config/initializers/rails_config.rb
+
+```ruby
+RailsConfig.setup do |config|
+  config.const_name = 'settings'
+end
+```
+
+`Settings.some_array` becomes `[3, 4]`.
+
+If you want the old behavior (merging arrays), just set the `overwrite_arrays` var to `false` in your `config/initializers/rails_config.rb` file. Eg:
+
+```ruby
+RailsConfig.setup do |config|
+  config.overwrite_arrays = false
+  config.const_name = 'settings'
+end
+```
+
+`Settings.some_array` becomes `[1, 2, 3, 4]`.
 
 ## Contributing
 

lib/rails_config.rb

@@ -10,9 +10,10 @@ module RailsConfig
   # ensures the setup only gets run once
   @@_ran_once = false
 
-  mattr_accessor :const_name, :use_env
+  mattr_accessor :const_name, :use_env, :overwrite_arrays
   @@const_name = "Settings"
   @@use_env = false
+  @@overwrite_arrays = true
 
   def self.setup
     yield self if @@_ran_once == false
@@ -23,6 +24,7 @@ def self.setup
   # if the first file if they exist in the first file.
   def self.load_files(*files)
     config = Options.new
+    config.overwrite_arrays = overwrite_arrays
 
     # add yaml sources
     [files].flatten.compact.uniq.each do |file|

lib/rails_config/options.rb

@@ -2,6 +2,7 @@
 module RailsConfig
   class Options < OpenStruct
     include Enumerable
+    attr_accessor :overwrite_arrays
 
     def keys()   marshal_dump.keys;   end
     def empty?() marshal_dump.empty?; end
@@ -23,7 +24,7 @@ def reload_env!
         key.to_s.split('.').reverse.each do |element|
           hash = {element => hash}
         end
-        DeepMerge.deep_merge!(hash, conf, :preserve_unmergeables => false)
+        DeepMerge.deep_merge!(hash, conf, :preserve_unmergeables => false, :overwrite_arrays => overwrite_arrays)
       end
 
       merge!(conf[RailsConfig.const_name] || {})
@@ -40,7 +41,7 @@ def reload!
         if conf.empty?
           conf = source_conf
         else
-          DeepMerge.deep_merge!(source_conf, conf, :preserve_unmergeables => false)
+          DeepMerge.deep_merge!(source_conf, conf, :preserve_unmergeables => false, :overwrite_arrays => overwrite_arrays)
         end
       end
 

lib/rails_config/vendor/deep_merge.rb

@@ -25,6 +25,8 @@ class InvalidParameter < StandardError; end
   #      Set to true to skip any unmergeable elements from source
   #   :knockout_prefix        DEFAULT: nil
   #      Set to string value to signify prefix which deletes elements from existing element
+  #   :overwrite_arrays       DEFAULT: true
+  #      Set to true to overwrite arrays intead of merging elements
   #   :sort_merged_arrays     DEFAULT: false
   #      Set to true to sort all arrays that are merged together
   #   :unpack_arrays          DEFAULT: nil
@@ -59,6 +61,7 @@ class InvalidParameter < StandardError; end
   def DeepMerge.deep_merge!(source, dest, options = {})
     # turn on this line for stdout debugging text
     merge_debug = options[:merge_debug] || false
+    overwrite_arrays = options[:overwrite_arrays] || false
     overwrite_unmergeable = !options[:preserve_unmergeables]
     knockout_prefix = options[:knockout_prefix] || nil
     if knockout_prefix == ""; raise InvalidParameter, "knockout_prefix cannot be an empty string in deep_merge!"; end
@@ -127,7 +130,9 @@ def DeepMerge.deep_merge!(source, dest, options = {})
           puts if merge_debug
         end
         puts "#{di} merging arrays: #{source.inspect} :: #{dest.inspect}" if merge_debug
-        dest = dest | source
+        unless overwrite_arrays
+          dest = dest | source
+        end
         if sort_merged_arrays; dest.sort!; end
       elsif overwrite_unmergeable
         puts "#{di} overwriting dest: #{source.inspect} -over-> #{dest.inspect}" if merge_debug

spec/rails_config_spec.rb

@@ -162,6 +162,24 @@
       config.inner2.inner2_inner.marshal_dump.keys.size.should eq 3
     end
 
+    it "should merge arrays from multiple configs" do
+      config.arraylist1.size.should eq 3
+      config.arraylist2.inner.size.should eq 3
+    end
+  end
+
+  context "Deep Merging (old behavior)" do
+    let(:config) do
+      files = ["#{fixture_path}/deep_merge/config1.yml", "#{fixture_path}/deep_merge/config2.yml"]
+      RailsConfig.overwrite_arrays = false
+      RailsConfig.load_files(files)
+    end
+
+    it "should merge hashes from multiple configs" do
+      config.inner.marshal_dump.keys.size.should eq 3
+      config.inner2.inner2_inner.marshal_dump.keys.size.should eq 3
+    end
+
     it "should merge arrays from multiple configs" do
       config.arraylist1.size.should eq 6
       config.arraylist2.inner.size.should eq 6