Use $XDG_CONFIG_HOME to load config

.gitignore

@@ -5,3 +5,4 @@ Gemfile.lock
 .env
 coverage
 tmp
+/vendor/

README.md

@@ -43,12 +43,16 @@ gem install gem-release
 # Configuration
 
 Defaults for all options can be specified in a config file at either one of
-these locations:
+these locations in this specific order:
 
-* `~/.gem_release/config.yml`
-* `~/.gem_release.yml`
-* `./.gem_release/config.yml`
-* `./.gem_release.yml`
+* ./.gem_release/config.yml
+* ./.gem_release.yml
+* $XDG_CONFIG_HOME/.gem_release/config.yml
+* $XDG_CONFIG_HOME/.gem_release.yml
+* ~/.gem_release/config.yml
+* ~/.gem_release.yml
+
+`$XDG_CONFIG_HOME` defaults to `~/.config` if not set.
 
 Config files must be in the [YAML](http://www.yaml.org/) format, and list
 options per command. Common options can be set on the root.

README.md.erb

@@ -43,12 +43,13 @@ gem install gem-release
 # Configuration
 
 Defaults for all options can be specified in a config file at either one of
-these locations:
+these locations in this specific order:
 
-* `~/.gem_release/config.yml`
-* `~/.gem_release.yml`
-* `./.gem_release/config.yml`
-* `./.gem_release.yml`
+<% class Gem::Release::Config::Files; def xdg_config_home; '$XDG_CONFIG_HOME/'; end; end -%>
+<% Gem::Release::Config::Files.new.combine_paths.map do |path| -%>
+* <%= path %>
+<% end %>
+`$XDG_CONFIG_HOME` defaults to `~/.config` if not set.
 
 Config files must be in the [YAML](http://www.yaml.org/) format, and list
 options per command. Common options can be set on the root.

lib/gem/release/config/files.rb

@@ -7,28 +7,36 @@ class Config
       class Files
         include Helper::Hash
 
-        PATHS = %w(
-          ./.gem_release/config.yml
-          ./.gem_release.yml
-          ~/.gem_release/config.yml
-          ~/.gem_release.yml
-        )
+        FILES = %w[.gem_release/config.yml .gem_release.yml]
 
         def load
           return {} unless path
           symbolize_keys(YAML.load_file(path) || {})
         end
 
+        def combine_paths
+          folders = ['./', xdg_config_home, '~/']
+
+          folders.product(FILES).map do |folder, file|
+            File.join(folder, file)
+          end
+        end
+
         private
 
           def path
             @path ||= paths.first
           end
 
           def paths
-            paths = PATHS.map { |path| File.expand_path(path) }
+            paths = combine_paths.map { |path| File.expand_path(path) }
             paths.select { |path| File.exist?(path) }
           end
+
+          def xdg_config_home
+            home_config =  File.join(ENV.fetch('HOME'), '.config')
+            ENV.fetch('XDG_CONFIG_HOME', home_config)
+          end
       end
     end
   end

spec/gem/release/config_spec.rb

@@ -1,6 +1,7 @@
 describe Gem::Release::Config do
-  let(:global) { { bump: { commit: false }, tag: { push: false }, quiet: true } }
-  let(:local)  { { bump: { commit: true, push: true }, quiet: false } }
+  let(:global) { { release: { host: 'https://example.com/global' } } }
+  let(:local) { { release: { host: 'https://example.com/local' } } }
+  let(:xdg_config) { { release: { host: 'https://example.com/xdg' } } }
 
   subject { described_class.new.opts }
 
@@ -37,6 +38,41 @@
       before { write './.gem_release.yml', '' }
       it { should eq({}) }
     end
+
+    describe 'XDG_CONFIG_HOME' do
+      describe 'default' do
+        before { write File.join(ENV.fetch('HOME'), '.config/.gem_release.yml'), YAML.dump(xdg_config) }
+        it { should eq xdg_config }
+      end
+
+      describe 'set to ~/.my-little-config' do
+        env XDG_CONFIG_HOME: '~/.my-little-config'
+        before { write '~/.my-little-config/.gem_release.yml', YAML.dump(xdg_config) }
+        it { should eq xdg_config }
+      end
+    end
+
+    describe 'all three ./.gem_release.yml, XDG_CONFIG_HOME, and ~/.gem_release.yml' do
+      before { write './.gem_release.yml', YAML.dump(local) }
+      env XDG_CONFIG_HOME: '~/.my-little-config'
+      before { write '~/.my-little-config/.gem_release.yml', YAML.dump(xdg_config) }
+      before { write '~/.gem_release.yml', YAML.dump(global) }
+      it { should eq local }
+    end
+
+    describe 'both XDG_CONFIG_HOME and ~/.gem_release.yml' do
+      describe 'XDG_CONFIG_HOME default' do
+        before { write File.join(ENV.fetch('HOME'), '.config/.gem_release.yml'), YAML.dump(xdg_config) }
+        before { write '~/.gem_release.yml', YAML.dump(global) }
+        it { should eq xdg_config }
+      end
+      describe 'XDG_CONFIG_HOME set to ~/.my-little-config' do
+        env XDG_CONFIG_HOME: '~/.my-little-config'
+        before { write '~/.my-little-config/.gem_release.yml', YAML.dump(xdg_config) }
+        before { write '~/.gem_release.yml', YAML.dump(global) }
+        it { should eq xdg_config }
+      end
+    end
   end
 
   describe 'both env and files' do