fix: Set avatar for users(agent/contact) in slack channels (#7960)

spec/controllers/slack_uploads_controller_spec.rb

@@ -0,0 +1,44 @@
+require 'rails_helper'
+
+RSpec.describe SlackUploadsController do
+  describe 'GET #show' do
+    context 'when a valid blob key is provided' do
+      file = Rack::Test::UploadedFile.new('spec/assets/avatar.png', 'image/png')
+      blob = ActiveStorage::Blob.create_and_upload! io: file, filename: 'avatar.png'
+
+      it 'redirects to the blob service URL' do
+        get :show, params: { blob_key: blob.key }
+        redirect_path = response.location
+        expect(redirect_path).to match(%r{rails/active_storage/representations/redirect/.*/avatar.png})
+      end
+    end
+
+    context 'when an invalid blob key is provided' do
+      it 'returns contact default avatar url if the user is contact' do
+        get :show, params: { key: 'invalid_key', sender_type: 'contact' }
+        redirect_path = response.location
+        expect(redirect_path).to match(%r{integrations/slack/contact.png})
+      end
+
+      it 'returns agent default avatar url if the user is agent' do
+        get :show, params: { key: 'invalid_key', sender_type: 'user' }
+        redirect_path = response.location
+        expect(redirect_path).to match(%r{integrations/slack/user.png})
+      end
+    end
+
+    context 'when no blob key is provided' do
+      it 'returns contact default avatar url if the user is contact' do
+        get :show, params: { sender_type: 'contact' }
+        redirect_path = response.location
+        expect(redirect_path).to match(%r{integrations/slack/contact.png})
+      end
+
+      it 'returns agent default avatar url if the user is agent' do
+        get :show, params: { sender_type: 'user' }
+        redirect_path = response.location
+        expect(redirect_path).to match(%r{integrations/slack/user.png})
+      end
+    end
+  end
+end