Trim stacks below user test code, for JUnit runner-caught exceptions

3 files changed, 52 insertions, 2 deletions

diff --git a/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/JunitRunner.java b/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/JunitRunner.java
index a7c40ddfad2..05c5dd24f1e 100644
--- a/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/JunitRunner.java
+++ b/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/JunitRunner.java
@@ -198,7 +198,10 @@ public class JunitRunner extends AbstractComponent implements TestRunner {
         launcher.execute(discoveryRequest);
         var report = summaryListener.getSummary();
         var failures = report.getFailures().stream()
-                .map(failure -> new TestReport.Failure(failure.getTestIdentifier().getUniqueId(), failure.getException()))
+                .map(failure -> {
+                    TestReport.trimStackTraces(failure.getException(), JunitRunner.class.getName());
+                    return new TestReport.Failure(failure.getTestIdentifier().getUniqueId(), failure.getException());
+                })
                 .collect(Collectors.toList());
         long inconclusive = isProductionTest ? failures.stream()
                                                        .filter(failure -> failure.exception() instanceof InconclusiveTestException)
diff --git a/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/TestReport.java b/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/TestReport.java
index a9ac950e30a..bcb865c55ff 100644
--- a/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/TestReport.java
+++ b/vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/TestReport.java
@@ -10,6 +10,7 @@ import static com.yahoo.vespa.testrunner.TestRunner.Status.FAILURE;
 import static com.yahoo.vespa.testrunner.TestRunner.Status.INCONCLUSIVE;
 import static com.yahoo.vespa.testrunner.TestRunner.Status.NO_TESTS;
 import static com.yahoo.vespa.testrunner.TestRunner.Status.SUCCESS;
+import static java.util.Arrays.copyOf;
 
 /**
  * @author mortent
@@ -119,4 +120,28 @@ public class TestReport {
 
     }
 
+    /**
+     * Recursively trims stack traces for the given throwable and its causes/suppressed.
+     * This is based on the assumption that the relevant stack is anything above the first native
+     * reflection invocation, above any frame in the given root class.
+     */
+    static void trimStackTraces(Throwable thrown, String testFrameworkRootClass) {
+        if (thrown == null)
+            return;
+
+        StackTraceElement[] stack = thrown.getStackTrace();
+        int i = stack.length;
+        boolean rootedInTestFramework = false;
+        while (--i > 0 && ! stack[i].isNativeMethod()) // Native method invokes the first user test frame.
+            rootedInTestFramework |= testFrameworkRootClass.equals(stack[i].getClassName());
+
+        if (rootedInTestFramework && i > 0)
+            thrown.setStackTrace(copyOf(stack, i));
+
+        for (Throwable suppressed : thrown.getSuppressed())
+            trimStackTraces(suppressed, testFrameworkRootClass);
+
+        trimStackTraces(thrown.getCause(), testFrameworkRootClass);
+    }
+
 }
diff --git a/vespa-osgi-testrunner/src/test/java/com/yahoo/vespa/testrunner/AggregateTestRunnerTest.java b/vespa-osgi-testrunner/src/test/java/com/yahoo/vespa/testrunner/AggregateTestRunnerTest.java
index f8e13ac5d6a..14e139b3fbf 100644
--- a/vespa-osgi-testrunner/src/test/java/com/yahoo/vespa/testrunner/AggregateTestRunnerTest.java
+++ b/vespa-osgi-testrunner/src/test/java/com/yahoo/vespa/testrunner/AggregateTestRunnerTest.java
@@ -1,6 +1,8 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.testrunner;
 
+import com.yahoo.exception.ExceptionUtils;
+import com.yahoo.vespa.testrunner.TestReport.Failure;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -123,7 +125,7 @@ class AggregateTestRunnerTest {
         // Verify reports are merged.
         assertNull(runner.getReport());
 
-        TestReport.Failure failure = new TestReport.Failure("test", null);
+        Failure failure = new Failure("test", null);
         TestReport report = TestReport.builder()
                                       .withLogs(List.of(record1))
                                       .withFailures(List.of(failure))
@@ -156,6 +158,26 @@ class AggregateTestRunnerTest {
         assertEquals(FAILURE, JunitRunner.createReportWithFailedInitialization(new RuntimeException("hello")).status());
     }
 
+    @Test
+    void testStackTrimming() {
+        try {
+            try {
+                throw new RuntimeException("inner");
+            }
+            catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        }
+        catch (Exception e) {
+            TestReport.trimStackTraces(e, "org.junit.platform.launcher.core.SessionPerRequestLauncher");
+            assertEquals("java.lang.RuntimeException: java.lang.RuntimeException: inner\n" +
+                         "\tat com.yahoo.vespa.testrunner.AggregateTestRunnerTest.testStackTrimming(AggregateTestRunnerTest.java:168)\n" +
+                         "Caused by: java.lang.RuntimeException: inner\n" +
+                         "\tat com.yahoo.vespa.testrunner.AggregateTestRunnerTest.testStackTrimming(AggregateTestRunnerTest.java:165)\n",
+                         ExceptionUtils.getStackTraceAsString(e));
+        }
+    }
+
     static class MockTestRunner implements TestRunner {
 
         final List<LogRecord> log = new ArrayList<>();