Helper for use in RSpec/Capybara feature tests to find a table on a page and convert it into an array of arrays, so that you can make an assertion on it. Similar to Cucumber's #tableize but is better about stringifying cell content.

table_helpers.rb

module TableHelpers
  VALID_FORMATS = [:html, :text]

  # Find a table on the page and convert it to an array of arrays.
  #
  # selector_or_node - A String CSS selector to find the table, or a
  #                    Nokogiri::XML::Node object (if you already have a
  #                    reference to the table).
  # options          - Optional hash:
  #                    columns - An Integer or Range of Integers. Lets you
  #                              select a slice of columns. Useful if one of
  #                              the columns is used solely for interaction
  #                              purposes (e.g., contains buttons or
  #                              checkboxes).
  #                    as      - A Symbol. How to convert cell content. :html
  #                              will get the content as HTML, :text will strip
  #                              the HTML. (Default: :text)
  #
  # Returns an Array of Arrays. Each outer Array is a row, each inner Array is a
  # cell.
  #
  def table_contents(selector_or_node, options = {})
    format = options[:as] || :text
    selected_columns = options[:columns]
    selected_rows = options[:rows]

    unless VALID_FORMATS.include?(format)
      raise ArgumentError, "Invalid format #{format}. Format must be one of: #{VALID_FORMATS.join(', ')}"
    end

    if selected_columns && !selected_columns.is_a?(Range)
      selected_columns = Range.new(selected_columns, selected_columns)
    end

    if selected_rows && !selected_rows.is_a?(Range)
      selected_rows = Range.new(selected_rows, selected_rows)
    end

    # Wait for the element to appear on the page
    find(selector_or_node)

    if selector_or_node.is_a?(Nokogiri::XML::Node)
      trs = selector_or_node.css('tr')
    else
      doc = Nokogiri::HTML.parse(page.html)
      trs = doc.css("#{selector_or_node} tr")
    end

    rows = []
    trs.each_with_index do |tr, i|
      if selected_rows.nil? || selected_rows.include?(i)
        cells = []
        tr.css('th, td').each_with_index do |td, j|
          if selected_columns.nil? || selected_columns.include?(j)
            cells << case format
              when :html then td.inner_html
              when :text then td.content.strip.squish
            end
          end
        end
        rows << cells
      end
    end

    rows
  end
end

RSpec.configure do |c|
  c.include(TableHelpers, type: :feature)
end