FEATURE: Allow theme settings to request refresh (#15037)

Similar to site settings, adds support for `refresh` option to theme settings.

```yaml
super_feature_enabled:
  type: bool
  default: false
  refresh: true
```

app/models/theme.rb

@@ -94,6 +94,13 @@ class Theme < ActiveRecord::Base
     clear_cached_settings!
     DB.after_commit { ColorScheme.hex_cache.clear }
     notify_theme_change(with_scheme: notify_with_scheme)
+
+    if theme_setting_requests_refresh
+      DB.after_commit do
+        Discourse.request_refresh!
+        self.theme_setting_requests_refresh = false
+      end
+    end
   end
 
   def update_child_components
@@ -572,6 +579,10 @@ class Theme < ActiveRecord::Base
     raise Discourse::NotFound unless target_setting
 
     target_setting.value = new_value
+
+    if target_setting.requests_refresh?
+      self.theme_setting_requests_refresh = true
+    end
   end
 
   def update_translation(translation_key, new_value)
@@ -727,6 +738,8 @@ class Theme < ActiveRecord::Base
 
   private
 
+  attr_accessor :theme_setting_requests_refresh
+
   def to_scss_variable(name, value)
     escaped = SassC::Script::Value::String.quote(value, sass: true)
     "$#{name}: unquote(#{escaped});"

lib/theme_settings_manager.rb

@@ -37,6 +37,10 @@ class ThemeSettingsManager
     @opts[:description] # Old method of specifying description. Is now overridden by locale file
   end
 
+  def requests_refresh?
+    @opts[:refresh]
+  end
+
   def value=(new_value)
     ensure_is_valid_value!(new_value)
 

lib/theme_settings_parser.rb

@@ -43,6 +43,8 @@ class ThemeSettingsParser
     opts[:textarea] = !!raw_opts[:textarea]
     opts[:json_schema] = raw_opts[:json_schema]
 
+    opts[:refresh] = !!raw_opts[:refresh]
+
     opts
   end
 

spec/fixtures/theme_settings/valid_settings.yaml

@@ -80,3 +80,7 @@ invalid_json_schema_setting:
 valid_json_schema_setting:
   default: ""
   json_schema: '{ "type": "array", "uniqueItems": true, "items": { "type": "object", "properties": { "color": { "type": "string" }, "icon": { "type": "string" } }, "additionalProperties": false } }'
+
+causes_refresh:
+  default: ""
+  refresh: true

spec/models/theme_spec.rb

@@ -902,4 +902,44 @@ HTML
       expect(new_digest).to eq(digest)
     end
   end
+
+  describe "#update_setting" do
+    it "requests clients to refresh if `refresh: true`" do
+      theme.set_field(target: :settings, name: "yaml", value: <<~YAML)
+        super_feature_enabled:
+          type: bool
+          default: false
+          refresh: true
+      YAML
+
+      ThemeSetting.create!(theme: theme, data_type: ThemeSetting.types[:bool], name: "super_feature_enabled")
+      theme.save!
+
+      messages = MessageBus.track_publish do
+        theme.update_setting(:super_feature_enabled, true)
+        theme.save!
+      end.filter { |m| m.channel == "/global/asset-version" }
+
+      expect(messages.count).to eq(1)
+    end
+
+    it "does not request clients to refresh if `refresh: false`" do
+      theme.set_field(target: :settings, name: "yaml", value: <<~YAML)
+        super_feature_enabled:
+          type: bool
+          default: false
+          refresh: false
+      YAML
+
+      ThemeSetting.create!(theme: theme, data_type: ThemeSetting.types[:bool], name: "super_feature_enabled")
+      theme.save!
+
+      messages = MessageBus.track_publish do
+        theme.update_setting(:super_feature_enabled, true)
+        theme.save!
+      end.filter { |m| m.channel == "/global/asset-version" }
+
+      expect(messages.count).to eq(0)
+    end
+  end
 end