Screenshot on every failure using Scalatest - scala

Question

I would like to take a screenshot on every fail test in a Spec or Suite using ScalaTest.
The Scala Test website shows how to take screenshots surrounding every code that might fail with this:
withScreenshot {
drive.findElement(By.id("login")).getAttribute("value") should be ("Login")
}
There is this post that tries to explain, but I could not understand what exactly should be done.
I also found the class ScreenshotOnFailure.scala, but could not use it, once it's private and has a package restriction.
Can anyone tell me if there's a way to intercept any failure and then take a screenshot?

Answer 1

Just to have a final answer I'm writing the way I could solve the problem based on the approach from this post mentioned in the question.
In short, the solution ended up like this (pseudo-code).
trait Screenshots extends FunSpec {
...
override def withFixture(test: NoArgTest): Outcome = {
val outcome = test()
// If the test fails, it will hold an exception.
// You can get the message with outcome.asInstanceOf[Failure].exception
if (outcome.isExceptional) {
// Implement Selenium code to save the image using a random name
// Check: https://stackoverflow.com/questions/3422262/take-a-screenshot-with-selenium-webdriver
}
outcome
}
}
class MySpec extends Screenshots {
...
describe("Scenario A") {
describe("when this") {
it("the field must have value 'A'") {
// It will save a screenshot either if the selector is wrong or the assertion fails
driver.findElement(By.id("elementA")).getAttribute("value") should be ("A")
}
}
}
}
From this point on, all Specs that extend the Screenshot trait will intercept errors and save a screenshot.
Just to complement, surrounding areas with withScreenshot(), as mentioned in the question, saves only failure on assertions, but it does not save a screenshot when the test fails due an element not found (e.g. wrong selector).
With the code above, all failures will save a screenshot.