Relocate plugins command unit test to feature test

bridgetown-core/test/features/feature_helper.rb

@@ -56,9 +56,10 @@ def after_teardown
 
   ####
 
-  def run_bridgetown(command, args = "", skip_status_check: false)
+  def run_bridgetown(command, args = "", skip_status_check: false, trace: true)
     args = args.strip.split # Shellwords?
-    process, output = exec_command("ruby", Paths.bridgetown_bin.to_s, command, *args, "--trace")
+    args << "--trace" if trace
+    process, output = exec_command("ruby", Paths.bridgetown_bin.to_s, command, *args)
     unless skip_status_check
       assert process.exitstatus.zero?, "Bridgetown process failed: #{process} \n#{output}"
     end

bridgetown-core/test/features/test_plugins_command.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require "features/feature_helper"
+
+class TestPluginsCommand < BridgetownFeatureTest
+  describe "list registered plugins" do
+    before do
+      create_directory "config"
+      create_file "config/initializers.rb", <<~RUBY
+        Bridgetown.configure do |config|
+        end
+      RUBY
+    end
+
+    it "excludes init (Initializer) from registered plugins list" do
+      _, output = run_bridgetown "plugins", "list", trace: false
+      output = Bridgetown::Foundation::Packages::Ansi.strip(output)
+
+      refute_includes output, "init (Initializer)"
+      assert_includes output, "Registered Plugins: 5"
+    end
+  end
+end