Add failing test for #20190

spec/features/projects/files/creating_a_file_spec.rb

+require 'spec_helper'
+
+feature 'User wants to create a file', feature: true do
+  include WaitForAjax
+
+  let(:project) { create(:project) }
+  let(:user) { create(:user) }
+
+  background do
+    project.team << [user, :master]
+    login_as user
+    visit namespace_project_new_blob_path(project.namespace, project, project.default_branch)
+  end
+
+  def submit_new_file(options)
+    file_name = find('#file_name')
+    file_name.set options[:file_name] || 'README.md'
+
+    file_content = find('#file-content')
+    file_content.set options[:file_content] || 'Some content'
+
+    click_button 'Commit Changes'
+  end
+
+  scenario 'file name contains Chinese characters' do
+    submit_new_file(file_name: '测试.md')
+    expect(page).to have_content 'The file has been successfully created.'
+  end
+
+  scenario 'directory name contains Chinese characters' do
+    submit_new_file(file_name: '中文/测试.md')
+    expect(page).to have_content 'The file has been successfully created.'
+  end
+
+  scenario 'file name contains invalid characters' do
+    submit_new_file(file_name: '\\')
+    expect(page).to have_content 'Your changes could not be committed, because the file name can contain only'
+  end
+
+  scenario 'file name contains directory traversal' do
+    submit_new_file(file_name: '../README.md')
+    expect(page).to have_content 'Your changes could not be committed, because the file name cannot include directory traversal.'
+  end
+end