Thanks for the datasources; they confirmed what I was doing!
And then, just to finalize this, as my previous script was indeed a very crude and hastily comprised. I had to abandon all Asserts (including softAsserts), so a better generalized version below having two datapoints: FailedStep and GeneralSuccess (not really needed, but just for clarity). Two graphs as well having the same ones where FailedStep has vertical label description as "ZeroIsGood" and GeneralSuccess has "OneIsGood". Of course alert thresholds set respectively. This quite probably fits my needs nicely when cloning and amending to multiple different tests. (One development step would still be to get rid of the "--no-sandbox" as it is a security risk to run chromedriver as root.)
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.WebElement;
import java.util.*;
import java.net.MalformedURLException;
import java.net.URL;
ChromeOptions chromeOptions = new ChromeOptions();
chromeOptions.addArguments("--no-sandbox");
chromeOptions.addArguments("--headless");
WebDriver driver = new ChromeDriver(options=chromeOptions);
driver.get("http://juhani.exdecfinland.org/~tforsell/home.html");
if ( driver.getTitle().contains("404") ) //Only way to catch page not found (https://stackoverflow.com/questions/17657037/catching-a-404-error-with-selenium)
{ println "GeneralSuccess=0"; println "FailedStep=1"; driver.quit(); return 0; }
} catch (Exception ex) { println "GeneralSuccess=0"; println "FailedStep=1"; driver.quit(); return 0; }
driver.findElement(By.cssSelector("a:nth-child(4) > img")).click(); //Click the motorbike image in the right frame
if ( driver.getTitle().contains("404") ) //Only way to catch page not found (https://stackoverflow.com/questions/17657037/catching-a-404-error-with-selenium)
{ println "GeneralSuccess=0"; println "FailedStep=2"; driver.quit(); return 0; }
} catch (Exception ex) { println "GeneralSuccess=0"; println "FailedStep=2"; driver.quit(); return 0; }
if ( !driver.findElement(By.cssSelector("h2:nth-child(56)")).getText().contains("Saksan reissu -Germany trip 2005") )
{ println "GeneralSuccess=0"; println "FailedStep=3"; driver.quit(); return 0; }
} catch (Exception ex) { println "GeneralSuccess=0"; println "FailedStep=3"; driver.quit(); return 0; }
println "GeneralSuccess=1"; println "FailedStep=0"; driver.quit(); return 0;