Change action name and fix code styling

Change action name to show and fix a few code style issues.

app/controllers/projects/metrics_dashboard_controller.rb

 # frozen_string_literal: true
-
-class Projects::MetricsDashboardController < Projects::ApplicationController
-  before_action :metrics_dashboard_page do
-    authorize_metrics_dashboard!
-
+module Projects
+  class MetricsDashboardController < Projects::ApplicationController
+    before_action :authorize_metrics_dashboard!
+    before_action do
       push_frontend_feature_flag(:prometheus_computed_alerts)
     end
 
-  def metrics_dashboard_page
+    def show
       if environment
         render 'projects/environments/metrics'
       else
@@ -19,14 +18,11 @@ class Projects::MetricsDashboardController < Projects::ApplicationController
 
     def environment
       @environment ||=
-      if metrics_dashboard_page_params[:environment]
-        project.environments.find(metrics_dashboard_page_params[:environment])
+        if params[:environment]
+          project.environments.find(params[:environment])
         else
           project.default_environment
         end
     end
-
-  def metrics_dashboard_page_params
-    params.permit(:environment)
   end
 end

config/routes/project.rb

@@ -26,7 +26,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
       scope '-' do
         get 'archive/*id', constraints: { format: Gitlab::PathRegex.archive_formats_regex, id: /.+?/ }, to: 'repositories#archive', as: 'archive'
         get 'd(/:dashboard_path)', constraints: { dashboard_path: /.+\.yml/ },
-          to: 'metrics_dashboard#metrics_dashboard_page', as: :metrics_dashboard_page, format: false
+          to: 'metrics_dashboard#show', as: :metrics_dashboard, format: false
 
         resources :artifacts, only: [:index, :destroy]
 

spec/requests/projects/metrics_dashboard_spec.rb

@@ -44,7 +44,7 @@ describe 'metrics dashboard page' do
     end
   end
 
-  describe 'GET /:namespace/:project/-d/:dashboard_path' do
+  describe 'GET /:namespace/:project/-/d/:dashboard_path' do
     let(:dashboard_path) { '.gitlab/dashboards/dashboard_path.yml' }
 
     it 'returns 200' do
@@ -58,7 +58,7 @@ describe 'metrics dashboard page' do
     end
   end
 
-  describe 'GET :/namespace/:project/-d/:dashboard_path?environment=:environment.id' do
+  describe 'GET :/namespace/:project/-/d/:dashboard_path?environment=:environment.id' do
     let(:dashboard_path) { '.gitlab/dashboards/dashboard_path.yml' }
 
     it 'returns 200' do
@@ -80,6 +80,6 @@ describe 'metrics dashboard page' do
   end
 
   def send_request(params = {})
-    get namespace_project_metrics_dashboard_page_path(namespace_id: project.namespace, project_id: project, **params)
+    get namespace_project_metrics_dashboard_path(namespace_id: project.namespace, project_id: project, **params)
   end
 end