DEV: improve design of site setting default provider

This refactors it so "Defaults provider" is only responsible for "defaults"

Locale handling and management of locale settings is moved back into
SiteSettingExtension

This eliminates complex state management using DistributedCache and makes
it way easier to test SiteSettingExtension

spec/components/site_setting_extension_spec.rb

@@ -505,6 +505,15 @@ describe SiteSettingExtension do
   end
 
   describe "shadowed_by_global" do
+
+    context "default_locale" do
+      it "supports adding a default locale via a global" do
+        global_setting :default_locale, 'zh_CN'
+        settings.default_locale = 'en'
+        expect(settings.default_locale).to eq('zh_CN')
+      end
+    end
+
     context "without global setting" do
       before do
         settings.setting(:trout_api_key, 'evil', shadowed_by_global: true)

spec/components/site_settings/defaults_provider_spec.rb

@@ -26,20 +26,7 @@ describe SiteSettings::DefaultsProvider do
     new_settings(provider_local)
   end
 
-  describe 'inserts default_locale into refresh' do
-    it 'when initialize' do
-      expect(settings.refresh_settings.include?(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY)).to be_truthy
-    end
-  end
-
   describe '.db_all' do
-    it 'collects values from db except default locale' do
-      settings.provider.save(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY,
-                             'en',
-                             SiteSetting.types[:string])
-      expect(settings.defaults.db_all).to eq([])
-    end
-
     it 'can collect values from db' do
       settings.provider.save('try_a', 1, SiteSetting.types[:integer])
       settings.provider.save('try_b', 2, SiteSetting.types[:integer])
@@ -55,11 +42,9 @@ describe SiteSettings::DefaultsProvider do
     end
 
     describe '.all' do
-      it 'returns all values according to the current locale' do
+      it 'returns all values according to locale' do
         expect(settings.defaults.all).to eq(test_override: 'default', test_default: 'test')
-        settings.defaults.site_locale = 'zh_CN'
-        settings.defaults.refresh_site_locale!
-        expect(settings.defaults.all).to eq(test_override: 'cn', test_default: 'test')
+        expect(settings.defaults.all('zh_CN')).to eq(test_override: 'cn', test_default: 'test')
       end
     end
 
@@ -72,11 +57,6 @@ describe SiteSettings::DefaultsProvider do
         expect(settings.defaults.get('test_override')).to eq 'default'
       end
 
-      it 'returns the default value according to current locale' do
-        expect(settings.defaults.get(:test_override)).to eq 'default'
-        settings.defaults.site_locale = 'zh_CN'
-        expect(settings.defaults.get(:test_override)).to eq 'cn'
-      end
     end
 
     describe '.set_regardless_of_locale' do
@@ -85,8 +65,7 @@ describe SiteSettings::DefaultsProvider do
       it 'sets the default value to a site setting regardless the locale' do
         settings.defaults.set_regardless_of_locale(:test_override, val)
         expect(settings.defaults.get(:test_override)).to eq val
-        settings.defaults.site_locale = 'zh_CN'
-        expect(settings.defaults.get(:test_override)).to eq val
+        expect(settings.defaults.get(:test_override, 'zh_CN')).to eq val
       end
 
       it 'handles the string' do
@@ -111,143 +90,13 @@ describe SiteSettings::DefaultsProvider do
         }.to raise_error(Discourse::InvalidParameters)
       end
     end
-
-    describe '.each' do
-      it 'yields the pair of site settings' do
-        expect { |b| settings.defaults.each(&b) }.to yield_successive_args([:test_override, 'default'], [:test_default, 'test'])
-        settings.defaults.site_locale = 'zh_CN'
-        expect { |b| settings.defaults.each(&b) }.to yield_successive_args([:test_override, 'cn'], [:test_default, 'test'])
-      end
-    end
-  end
-
-  describe '.site_locale' do
-    it 'returns the current site locale' do
-      expect(settings.defaults.site_locale).to eq 'en'
-    end
-
-    context 'when locale is set in the db' do
-      let(:db_val) { 'zr' }
-      let(:global_val) { 'gr' }
-
-      before do
-        settings.provider.save(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY,
-                               db_val,
-                               SiteSetting.types[:string])
-        settings.defaults.refresh_site_locale!
-      end
-
-      it 'should load from database' do
-        expect(settings.defaults.site_locale).to eq db_val
-      end
-
-      it 'prioritizes GlobalSetting than value from db' do
-        GlobalSetting.stubs(:default_locale).returns(global_val)
-        settings.defaults.refresh_site_locale!
-        expect(settings.defaults.site_locale).to eq global_val
-      end
-
-      it 'ignores blank GlobalSetting' do
-        GlobalSetting.stubs(:default_locale).returns('')
-        settings.defaults.refresh_site_locale!
-        expect(settings.defaults.site_locale).to eq db_val
-      end
-    end
-
-  end
-
-  describe '.site_locale=' do
-    it 'should store site locale in a distributed cache' do
-      expect(settings.defaults.class.class_variable_get(:@@site_locales))
-        .to be_a(DistributedCache)
-    end
-
-    it 'changes and store the current site locale' do
-      settings.defaults.site_locale = 'zh_CN'
-
-      expect(settings.defaults.site_locale).to eq('zh_CN')
-    end
-
-    it 'changes and store the current site locale' do
-      expect { settings.defaults.site_locale = 'random' }.to raise_error(Discourse::InvalidParameters)
-      expect(settings.defaults.site_locale).to eq 'en'
-    end
-
-    it "don't change when it's shadowed" do
-      GlobalSetting.stubs(:default_locale).returns('shadowed')
-      settings.defaults.site_locale = 'zh_CN'
-      expect(settings.defaults.site_locale).to eq 'shadowed'
-    end
-
-    it 'refresh_site_locale! when called' do
-      settings.defaults.expects(:refresh_site_locale!)
-      settings.defaults.site_locale = 'zh_CN'
-    end
-
-    it 'refreshes the client when changed' do
-      Discourse.expects(:request_refresh!).once
-      settings.defaults.site_locale = 'zh_CN'
-    end
-
-    it "doesn't refresh the client when changed" do
-      Discourse.expects(:request_refresh!).never
-      settings.defaults.site_locale = 'en'
-    end
-  end
-
-  describe '.locale_setting_hash' do
-    it 'returns the hash for client display' do
-      result = settings.defaults.locale_setting_hash
-
-      expect(result[:setting]).to eq(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY)
-      expect(result[:default]).to eq(SiteSettings::DefaultsProvider::DEFAULT_LOCALE)
-      expect(result[:type]).to eq(SiteSetting.types[SiteSetting.types[:enum]])
-      expect(result[:preview]).to be_nil
-      expect(result[:value]).to eq(SiteSettings::DefaultsProvider::DEFAULT_LOCALE)
-      expect(result[:category]).to eq(SiteSettings::DefaultsProvider::DEFAULT_CATEGORY)
-      expect(result[:valid_values]).to eq(LocaleSiteSetting.values)
-      expect(result[:translate_names]).to eq(LocaleSiteSetting.translate_names?)
-      expect(result[:description]).not_to be_nil
-    end
   end
 
   describe '.load_setting' do
-    it 'adds a setting to the cache' do
-      settings.defaults.load_setting('new_a', 1)
+    it 'adds a setting to the cache correctly' do
+      settings.defaults.load_setting('new_a', 1, zh_CN: 7)
       expect(settings.defaults[:new_a]).to eq 1
-    end
-
-    it 'takes care of locale default' do
-      settings.defaults.load_setting(:new_b, 1, locale_default: { zh_CN: 2, zh_TW: 2 })
-      expect(settings.defaults[:new_b]).to eq 1
-    end
-  end
-
-  describe '.refresh_site_locale!' do
-    it 'loads the change to locale' do
-      expect(settings.defaults.site_locale).to eq 'en'
-      settings.provider.save(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY,
-                             'zh_CN',
-                             SiteSetting.types[:string])
-      settings.defaults.refresh_site_locale!
-      expect(settings.defaults.site_locale).to eq 'zh_CN'
-    end
-
-    it 'loads from GlobalSettings' do
-      expect(settings.defaults.site_locale).to eq 'en'
-      GlobalSetting.stubs(:default_locale).returns('fr')
-      settings.defaults.refresh_site_locale!
-      expect(settings.defaults.site_locale).to eq 'fr'
-    end
-
-    it 'prioritized GlobalSettings than db' do
-      expect(settings.defaults.site_locale).to eq 'en'
-      settings.provider.save(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY,
-                             'zh_CN',
-                             SiteSetting.types[:string])
-      GlobalSetting.stubs(:default_locale).returns('fr')
-      settings.defaults.refresh_site_locale!
-      expect(settings.defaults.site_locale).to eq 'fr'
+      expect(settings.defaults.get(:new_a, 'zh_CN')).to eq 7
     end
   end
 
@@ -266,7 +115,7 @@ describe SiteSettings::DefaultsProvider do
     end
 
     it 'default_locale always exists' do
-      expect(settings.defaults.has_setting?(SiteSettings::DefaultsProvider::DEFAULT_LOCALE_KEY)).to be_truthy
+      expect(settings.defaults.has_setting?(:default_locale)).to be_truthy
     end
 
     it 'returns false when the key is not exist' do