expose post merge environments

app/controllers/projects/merge_requests_controller.rb

@@ -204,11 +204,17 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   end
   def ci_environments_status
+    sha = if ci_environments_status_on_merge_result?
+            @merge_request.merge_commit_sha
+          else
+            @merge_request.diff_head_sha
+          end
+
     environments =
       begin
-        @merge_request.environments_for(current_user).map do |environment|
+        @merge_request.environments_for(current_user, post_merge: ci_environments_status_on_merge_result?).map do |environment|
           project    = environment.project
-          deployment = environment.first_deployment_for(@merge_request.diff_head_sha)
+          deployment = environment.first_deployment_for(sha)
           stop_url =
             if can?(current_user, :stop_environment, environment)
@@ -274,6 +280,10 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     end
   end
+  def ci_environments_status_on_merge_result?
+    params[:target] == 'merge'
+  end
+
   private
   def target_branch_missing?

app/models/merge_request.rb

@@ -953,16 +953,17 @@ class MergeRequest < ActiveRecord::Base
     actual_head_pipeline&.success? || actual_head_pipeline&.skipped?
   end
-  def environments_for(current_user)
-    return [] unless diff_head_commit
+  def environments_for(current_user, post_merge: false)
+    commit = post_merge ? merge_commit : diff_head_commit
+    return [] unless commit
     @environments ||= Hash.new do |h, current_user|
       envs = EnvironmentsFinder.new(target_project, current_user,
-        ref: target_branch, commit: diff_head_commit, with_tags: true).execute
+        ref: target_branch, commit: commit, with_tags: true).execute
       if source_project
         envs.concat EnvironmentsFinder.new(source_project, current_user,
-          ref: source_branch, commit: diff_head_commit).execute
+          ref: source_branch, commit: commit).execute
       end
       h[current_user] = envs.uniq

spec/controllers/projects/merge_requests_controller_spec.rb

@@ -778,6 +778,14 @@ describe Projects::MergeRequestsController do
         expect(json_response.first['url']).to match /#{forked.full_path}/
       end
+      context "when target is 'merge'" do
+        it 'returns nothing' do
+          get_ci_environments_status(target: 'merge')
+
+          expect(json_response).to be_empty
+        end
+      end
+
       # we're trying to reduce the overall number of queries for this method.
       # set a hard limit for now. https://gitlab.com/gitlab-org/gitlab-ce/issues/52287
       it 'keeps queries in check' do
@@ -786,11 +794,15 @@ describe Projects::MergeRequestsController do
         expect(control_count).to be <= 137
       end
-      def get_ci_environments_status
-        get :ci_environments_status,
+      def get_ci_environments_status(extra_params = {})
+        params = {
           namespace_id: merge_request.project.namespace.to_param,
           project_id: merge_request.project,
-          id: merge_request.iid, format: 'json'
+          id: merge_request.iid,
+          format: 'json'
+        }
+
+        get :ci_environments_status, params.merge(extra_params)
       end
     end
   end