module PercyCapybara

Constants

CLIENT_INFO
ENV_INFO
PERCY_DEBUG
PERCY_LABEL
PERCY_SERVER_ADDRESS
VERSION

Public Instance Methods

percy_snapshot(name, options = {}) click to toggle source

Take a DOM snapshot and post it to the snapshot endpoint

# File lib/percy/capybara.rb, line 18
def percy_snapshot(name, options = {})
  return unless percy_enabled?

  page = Capybara.current_session

  begin
    page.evaluate_script(fetch_percy_dom)
    dom_snapshot = page
      .evaluate_script("(function() { return PercyDOM.serialize(#{options.to_json}) })()")

    response = fetch('percy/snapshot',
      name: name,
      url: page.current_url,
      dom_snapshot: dom_snapshot,
      client_info: CLIENT_INFO,
      environment_info: ENV_INFO,
      **options,)

    unless response.body.to_json['success']
      raise StandardError, data['error']
    end
  rescue StandardError => e
    log("Could not take DOM snapshot '#{name}'")

    if PERCY_DEBUG then log(e) end
  end
end

Private Instance Methods

fetch(url, data = nil) click to toggle source

Make an HTTP request (GET,POST) using Ruby's Net::HTTP. If `data` is present, `fetch` will POST as JSON.

# File lib/percy/capybara.rb, line 94
        def fetch(url, data = nil)
  uri = URI("#{PERCY_SERVER_ADDRESS}/#{url}")

  response = if data
    Net::HTTP.post(uri, data.to_json)
  else
    Net::HTTP.get_response(uri)
  end

  unless response.is_a? Net::HTTPSuccess
    raise StandardError, "Failed with HTTP error code: #{response.code}"
  end

  response
end

fetch_percy_dom() click to toggle source

Fetch the @percy/dom script, caching the result so it is only fetched once

# File lib/percy/capybara.rb, line 81
        def fetch_percy_dom
  return @percy_dom unless @percy_dom.nil?

  response = fetch('percy/dom.js')
  @percy_dom = response.body
end

log(msg) click to toggle source

# File lib/percy/capybara.rb, line 88
        def log(msg)
  puts "#{PERCY_LABEL} #{msg}"
end

percy_enabled?() click to toggle source

Determine if the Percy server is running, caching the result so it is only checked once

# File lib/percy/capybara.rb, line 47
        def percy_enabled?
  return @percy_enabled unless @percy_enabled.nil?

  begin
    response = fetch('percy/healthcheck')
    version = response['x-percy-core-version']

    if version.nil?
      log('You may be using @percy/agent ' \
          'which is no longer supported by this SDK. ' \
          'Please uninstall @percy/agent and install @percy/cli instead. ' \
          'https://docs.percy.io/docs/migrating-to-percy-cli')
      @percy_enabled = false
      return false
    end

    if version.split('.')[0] != '1'
      log("Unsupported Percy CLI version, #{version}")
      @percy_enabled = false
      return false
    end

    @percy_enabled = true
    true
  rescue StandardError => e
    log('Percy is not running, disabling snapshots')

    if PERCY_DEBUG then log(e) end
    @percy_enabled = false
    false
  end
end