feat: log all exceptions caught by RetryRule (#1663)

Currently, RetryRule show details only of the last caught exception, but this
one may not be the real reason of the test failure.
This change prints the stack trace of all caught expections when debug level
for RetryRule is at least 'debug', helping the develper to detect the real
cause of the test failure.

Fixes #1527

Co-authored-by: Mikhail Shabarov <[email protected]>

vaadin-testbench-core/src/main/java/com/vaadin/testbench/RetryRule.java

@@ -8,10 +8,16 @@
  */
 package com.vaadin.testbench;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.junit.internal.AssumptionViolatedException;
 import org.junit.rules.TestRule;
 import org.junit.runner.Description;
 import org.junit.runners.model.Statement;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * A retry rule is used to re-run a test several times in case of a random
@@ -61,20 +67,33 @@ private Statement statement(final Statement base,
         return new Statement() {
             @Override
             public void evaluate() throws Throwable {
-                Throwable caughtThrowable = null;
+                List<Throwable> caughtThrowables = new ArrayList<>();
                 for (int i = 0; i < maxAttempts; i++) {
                     try {
                         base.evaluate();
                         return;
                     } catch (AssumptionViolatedException t) {
                         throw t;
                     } catch (Throwable t) {
-                        caughtThrowable = t;
+                        caughtThrowables.add(t);
                     }
                 }
+                String testDisplayName = description.getDisplayName();
+                Logger logger = LoggerFactory.getLogger(RetryRule.class);
+                if (logger.isDebugEnabled() && caughtThrowables.size() > 1) {
+                    logger.debug("Caught {} exceptions for {} test",
+                            caughtThrowables.size(), testDisplayName);
+                    AtomicInteger attempt = new AtomicInteger();
+                    caughtThrowables
+                            .forEach(t -> logger.debug("\t{} [attempt {}]: {}",
+                                    testDisplayName, attempt.incrementAndGet(),
+                                    t.getMessage(), t));
+                }
+                Throwable lastCaught = caughtThrowables
+                        .get(caughtThrowables.size() - 1);
                 String errorMessage = String.format("%s: run failed %s times",
-                        description.getDisplayName(), maxAttempts);
-                throw new RuntimeException(errorMessage, caughtThrowable);
+                        testDisplayName, maxAttempts);
+                throw new RuntimeException(errorMessage, lastCaught);
             }
         };
     }