Complex assertion of table in Capybara - cucumber

Question

I have a table in my app.
Using Capybara and Cucumber, how do I assert that values 4.5 and 1.1 happen only in the Mike's row?
Is such assertion possible in Capybara?
Thanks!

Answer 1

You can use within to scope where you are searching for a specific value:
For example, to assert that value 4.5 happens in the second column of Mike's row, try the following:
within("table tr:nth-child(2)") do
find("td:nth-child(2)").text.should == 4.5
end
You can wrap these in helper methods for ease of use if you would like:
def within_row(num, &block)
within("table tr:nth-child(#{num})", &block)
end
def column_text(num)
find("td:nth-child(#{num})").text
end
Now you could make the same assertion about Mike's row by doing the following:
within_row(2) do
column_text(2).should == 4.1
end
Hopefully you will find one of these techniques useful for what you are trying to do.

Answer 2

Yes, it's possible and easy:
def td_text(n)
find(:xpath, "./td[#{n}]").text
end
h = {2 => 4.5, 3 => 1.1}
all('table tr').each do |row|
within row do
if td_text(1) == 'Mike'
h.each { |i, value| td_text(i).should == value.to_s }
else
h.each { |i, value| td_text(i).should_not == value.to_s }
end
end
end
Here's full script that you can use for testing
Update: I thought about it more. The code above will be very slow as every invocation of find and text in td_text will make new query to browser.
The only way to mitigate it that I see is to use JS and Nokogiri:
source = page.evaluate_script("document.getElementsByTagName('table')[0].innerHTML")
doc = Nokogiri::HTML(source)
def td_text(row, n)
  row.xpath("./td[#{n}]").text
end
h = {2 => 4.5, 3 => 1.1}
doc.css('tr').each do |row|
  if td_text(row, 1) == 'Mike'
    h.each { |i, value| td_text(row, i).should == value.to_s }
  else
    h.each { |i, value| td_text(row, i).should_not == value.to_s }
  end
end
The first variant of code runs about 200 milliseconds at my machine though the second one - 8 milliseconds. Good optimization!