Work on tests for mattermost

app/helpers/projects_helper.rb

@@ -150,10 +150,10 @@ module ProjectsHelper
 
   def mattermost_teams_options(teams)
     teams_options = teams.map do |id, options|
-      return nil unless id && options['display_name']
-      [options['display_name'], id]
-    end.compact
-    teams_options.unshift(['Select team...', '0'])
+      [options['display_name'] || options['name'], id]
+    end
+
+    teams_options.compact.unshift(['Select team...', '0'])
   end
 
   private

lib/mattermost/client.rb

 module Mattermost
+  class ClientError < Mattermost::Error; end
+
   class Client
     attr_reader :user
 
@@ -30,9 +32,9 @@ module Mattermost
       if response.success?
         json_response
       elsif json_response['message']
-        raise json_response['message']
+        raise ClientError(json_response['message'])
       else
-        raise 'Undefined error'
+        raise ClientError('Undefined error')
       end
     end
   end

lib/mattermost/session.rb

 module Mattermost
-  class NoSessionError < StandardError
+  class Error < StandardError; end
+
+  class NoSessionError < Error
     def message
       'No session could be set up, is Mattermost configured with Single Sign on?'
     end
   end
 
+  class ConnectionError < Error
+    def message
+      'Could not connect. Is Mattermost up?'
+    end
+  end
+
   # This class' prime objective is to obtain a session token on a Mattermost
   # instance with SSO configured where this GitLab instance is the provider.
   #
@@ -66,10 +74,14 @@ module Mattermost
 
     def get(path, options = {})
       self.class.get(path, options.merge(headers: @headers))
+    rescue Errno::ECONNREFUSED
+      raise ConnectionError
     end
 
     def post(path, options = {})
       self.class.post(path, options.merge(headers: @headers))
+    rescue Errno::ECONNREFUSED
+      raise ConnectionError
     end
 
     private

spec/models/project_services/mattermost_slash_commands_service_spec.rb

@@ -2,4 +2,39 @@ require 'spec_helper'
 
 describe MattermostSlashCommandsService, :models do
   it_behaves_like "chat slash commands service"
+
+  describe '#configure!' do
+    let(:project) { create(:empty_project) }
+    let(:service) { project.build_mattermost_slash_commands_service }
+    let(:user) { create(:user)}
+
+    before do
+      allow_any_instance_of(Mattermost::Session).to
+        receive(:with_session).and_yield
+    end
+
+    subject do
+      service.configure!(user, team_id: 'abc',
+        trigger: 'gitlab', url: 'http://trigger.url',
+        icon_url: 'http://icon.url/icon.png')
+    end
+
+    context 'the requests succeeds' do
+      it 'saves the service' do
+        expect { subject }.to change { project.services.count }.by(1)
+      end
+
+      it 'saves the token' do
+        subject
+
+        expect(service.reload.token).to eq('mynewtoken')
+      end
+    end
+
+    context 'an error is received' do
+      it 'shows error messages' do
+        expect(subject).to raise_error("Error")
+      end
+    end
+  end
 end