DEV: Plugins can extend color definitions (#10383)

spec/components/discourse_plugin_registry_spec.rb

@@ -227,6 +227,12 @@ describe DiscoursePluginRegistry do
       expect(registry.stylesheets[plugin_directory_name]).to eq(nil)
     end
 
+    it "registers color definitions properly" do
+      registry.register_asset("test.css", :color_definitions, plugin_directory_name)
+      expect(registry.color_definition_stylesheets[plugin_directory_name]).to eq('test.css')
+      expect(registry.stylesheets[plugin_directory_name]).to eq(nil)
+    end
+
     it "registers sass variable properly" do
       registry.register_asset("test.css", :variables)
 

spec/components/plugin/instance_spec.rb

@@ -11,8 +11,8 @@ describe Plugin::Instance do
   context "find_all" do
     it "can find plugins correctly" do
       plugins = Plugin::Instance.find_all("#{Rails.root}/spec/fixtures/plugins")
-      expect(plugins.count).to eq(3)
-      plugin = plugins[2]
+      expect(plugins.count).to eq(4)
+      plugin = plugins[3]
 
       expect(plugin.name).to eq("plugin-name")
       expect(plugin.path).to eq("#{Rails.root}/spec/fixtures/plugins/my_plugin/plugin.rb")

spec/components/stylesheet/compiler_spec.rb

@@ -84,5 +84,26 @@ describe Stylesheet::Compiler do
       expect(css).to include("--header_primary: #88af8e")
       expect(css).to include("--header_background-rgb: 248,116,92")
     end
+
+    context "with a plugin" do
+      before do
+        plugin = Plugin::Instance.new
+        plugin.path = "#{Rails.root}/spec/fixtures/plugins/color_definition/plugin.rb"
+        Discourse.plugins << plugin
+        plugin.activate!
+      end
+
+      after do
+        Discourse.plugins.pop
+        DiscoursePluginRegistry.reset!
+      end
+
+      it "includes color definitions from plugins" do
+        css, _map = Stylesheet::Compiler.compile_asset("color_definitions")
+
+        expect(css).to include("--plugin-color")
+      end
+    end
+
   end
 end