Add spec for Release API

Add spec for all release API - GET, POST, PUT, DELETE.
Also, fixes some minior bugs.

4 files changed, 153 insertions, 0 deletions

diff --git a/app/services/releases/concerns.rb b/app/services/releases/concerns.rb
new file mode 100644
index 00000000000..a04bb8f9e14
--- /dev/null
+++ b/app/services/releases/concerns.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+module Releases
+  module Concerns
+    extend ActiveSupport::Concern
+    include Gitlab::Utils::StrongMemoize
+
+    included do
+      def tag_name
+        params[:tag]
+      end
+
+      def ref
+        params[:ref]
+      end
+
+      def name
+        params[:name]
+      end
+
+      def description
+        params[:description]
+      end
+
+      def release
+        strong_memoize(:release) do
+          project.releases.find_by_tag(tag_name)
+        end
+      end
+
+      def existing_tag
+        strong_memoize(:existing_tag) do
+          repository.find_tag(tag_name)
+        end
+      end
+
+      def tag_exist?
+        existing_tag.present?
+      end
+
+      def repository
+        strong_memoize(:repository) do
+          project.repository
+        end
+      end
+    end
+  end
+end
diff --git a/app/services/releases/create_service.rb b/app/services/releases/create_service.rb
new file mode 100644
index 00000000000..210bdfbc699
--- /dev/null
+++ b/app/services/releases/create_service.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+module Releases
+  class CreateService < BaseService
+    include Releases::Concerns
+
+    def execute
+      return error('Access Denied', 403) unless allowed?
+      return error('Release already exists', 409) if release
+
+      new_tag = nil
+
+      unless tag_exist?
+        return error('Ref is not specified', 422) unless ref
+
+        result = Tags::CreateService
+          .new(project, current_user)
+          .execute(tag_name, ref, nil)
+
+        return result unless result[:status] == :success
+
+        new_tag = result[:tag]
+      end
+
+      create_release(existing_tag || new_tag)
+    end
+
+    private
+
+    def allowed?
+      Ability.allowed?(current_user, :create_release, project)
+    end
+
+    def create_release(tag)
+      release = project.releases.create!(
+        name: name,
+        description: description,
+        author: current_user,
+        tag: tag.name,
+        sha: tag.dereferenced_target.sha
+      )
+
+      success(tag: tag, release: release)
+    rescue ActiveRecord::RecordInvalid => e
+      error(e.message, 400)
+    end
+  end
+end
diff --git a/app/services/releases/destroy_service.rb b/app/services/releases/destroy_service.rb
new file mode 100644
index 00000000000..8c2bc3b4e6e
--- /dev/null
+++ b/app/services/releases/destroy_service.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Releases
+  class DestroyService < BaseService
+    include Releases::Concerns
+
+    def execute
+      return error('Tag does not exist', 404) unless existing_tag
+      return error('Release does not exist', 404) unless release
+      return error('Access Denied', 403) unless allowed?
+
+      if release.destroy
+        success(tag: existing_tag, release: release)
+      else
+        error(release.errors.messages || '400 Bad request', 400)
+      end
+    end
+
+    private
+
+    def allowed?
+      Ability.allowed?(current_user, :destroy_release, release)
+    end
+  end
+end
diff --git a/app/services/releases/update_service.rb b/app/services/releases/update_service.rb
new file mode 100644
index 00000000000..fabfa398c59
--- /dev/null
+++ b/app/services/releases/update_service.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Releases
+  class UpdateService < BaseService
+    include Releases::Concerns
+
+    def execute
+      return error('Tag does not exist', 404) unless existing_tag
+      return error('Release does not exist', 404) unless release
+      return error('Access Denied', 403) unless allowed?
+      return error('params is empty', 400) if empty_params?
+
+      if release.update(params)
+        success(tag: existing_tag, release: release)
+      else
+        error(release.errors.messages || '400 Bad request', 400)
+      end
+    end
+
+    private
+
+    def allowed?
+      Ability.allowed?(current_user, :update_release, release)
+    end
+
+    # rubocop: disable CodeReuse/ActiveRecord
+    def empty_params?
+      params.except(:tag).empty?
+    end
+    # rubocop: enable CodeReuse/ActiveRecord
+  end
+end