Complex XPath expressions fail

[jankowtf]

Complex CSS selectors (as identified by SelectorGadget) often fail:

test_that("Complex Xpath", {
  expect_is(s <- html_session("http://testing-ground.scraping.pro/"), "session")
  expect_is(s %>% follow_link(
    '//*[contains(concat( " ", @class, " " ), concat( " ", "caseblock", " " )) and (((count(preceding-sibling::*) + 1) = 1) and parent::*)]//a',
      "xpath"), "session")
})