Errors are shown when I am trying to run mobile automation TC using Appium + Capybara + Rspec + Ruby - ruby

Question

I am trying to adjust environment for mobile TC running using Appium + Capybara + Rspec + Ruby. I've created two files:
1) The first file is capybara_spec.rb:
require 'rspec'
require 'capybara/rspec'
require 'appium_capybara'
require 'site_prism'
require 'rspec/expectations'
require 'capybara-screenshot/rspec'
require 'launchy'
require '../specs/capybara_test_spec'
RSpec.configure do |config|
# config.include CapybaraTest
config.include RSpec::Matchers
config.include Capybara::DSL
Capybara.default_driver = :appium
Capybara.register_driver(:appium) do |app|
desired_caps = {
caps: {
platformName: 'Android',
versionNumber: '6.0.1',
deviceName: 'Galaxy S6',
device: 'Android',
app: '../app-mockBLE_SK.apk'
# browserName: 'Chrome'
}
}
Appium::Capybara::Driver.new(app, desired_caps)
end
Capybara.save_path = "../Reports" # path where screenshots are saved
config.after(:each) do |result|
CapybaraScreenshot.save_and_open_page_path if result.exception
Capybara.current_session.driver.browser.remove_app 'com.medtronicndt.envisionpro.mock'
Capybara.current_session.driver.browser.quit
end
Capybara::Screenshot.register_filename_prefix_formatter(:rspec) do |example|
"screenshot_#{example.description.gsub(' ', '-').gsub(/^.*\/spec\//, '')}"
end
end
Capybara.default_max_wait_time = 15
2) the second file with TC capybara_test_spec.rb:
require_relative '../specs/capybara_spec'
describe 'First ' do
context 'Mobile ' do
it 'Test:' do
a = Capybara.current_session.driver.browser.app_installed?('com.medtronicndt.envisionpro.mock')
puts "App Status: " + a.to_s
expect(a).to be true
end
end
end
After running I see the following errors:
1) First Mobile Test:
Failure/Error: if e = error()
Selenium::WebDriver::Error::NoSuchDriverError:
2.1) Failure/Error: a = Capybara.current_session.driver.browser.app_installed?('com.medtronicndt.envisionpro.mock')
Selenium::WebDriver::Error::NoSuchDriverError:
# ./capybara_test_spec.rb:6:in `block (3 levels) in <top (required)>'
2.2) Failure/Error: CapybaraScreenshot.save_and_open_page_path if result.exception
NoMethodError:
undefined method `save_and_open_page_path' for CapybaraScreenshot:Class
# ./capybara_spec.rb:34:in `block (2 levels) in <top (required)>'
2.3) Failure/Error: if e = error()
Selenium::WebDriver::Error::NoSuchDriverError:
Why these error are displayed? I see that app is started, also expect in TC returns true. But report is not created and TC is failed.