1 files changed, 44 insertions, 0 deletions
diff --git a/app/graphql/resolvers/environments/last_deployment_resolver.rb b/app/graphql/resolvers/environments/last_deployment_resolver.rb
new file mode 100644
index 00000000000..76f80112673
--- /dev/null
+++ b/app/graphql/resolvers/environments/last_deployment_resolver.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module Resolvers
+  module Environments
+    class LastDeploymentResolver < BaseResolver
+      argument :status,
+               Types::DeploymentStatusEnum,
+               required: true,
+               description: 'Status of the Deployment.'
+
+      type Types::DeploymentType, null: true
+
+      def resolve(status:)
+        return unless object.present? && object.is_a?(::Environment)
+
+        validate!(status)
+
+        find_last_deployment(status)
+      end
+
+      private
+
+      def find_last_deployment(status)
+        BatchLoader::GraphQL.for(object).batch(key: status) do |environments, loader, args|
+          association_name = "last_#{args[:key]}_deployment".to_sym
+
+          Preloaders::Environments::DeploymentPreloader.new(environments)
+            .execute_with_union(association_name, {})
+
+          environments.each do |environment|
+            loader.call(environment, environment.public_send(association_name)) # rubocop:disable GitlabSecurity/PublicSend
+          end
+        end
+      end
+
+      def validate!(status)
+        unless Deployment::FINISHED_STATUSES.include?(status.to_sym) ||
+            Deployment::UPCOMING_STATUSES.include?(status.to_sym)
+          raise Gitlab::Graphql::Errors::ArgumentError, "\"#{status}\" status is not supported."
+        end
+      end
+    end
+  end
+end