Improve error reporting in tests when there's an actual event/expected event mismatch.

--
MOS_MIGRATED_REVID=97878625

2 files changed, 8 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/events/EventCollector.java b/src/main/java/com/google/devtools/build/lib/events/EventCollector.java
index 774b3231f6..e8cc57ae4b 100644
--- a/src/main/java/com/google/devtools/build/lib/events/EventCollector.java
+++ b/src/main/java/com/google/devtools/build/lib/events/EventCollector.java
@@ -13,6 +13,8 @@
 // limitations under the License.
 package com.google.devtools.build.lib.events;
 
+import com.google.common.collect.Iterables;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
@@ -75,4 +77,9 @@ public class EventCollector extends AbstractEventHandler implements Iterable<Eve
   public void clear() {
     collected.clear();
   }
+
+  @Override
+  public String toString() {
+    return "EventCollector: " + Iterables.toString(collected);
+  }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/JunitTestUtils.java b/src/test/java/com/google/devtools/build/lib/testutil/JunitTestUtils.java
index efe15992d5..ecb44ca768 100644
--- a/src/test/java/com/google/devtools/build/lib/testutil/JunitTestUtils.java
+++ b/src/test/java/com/google/devtools/build/lib/testutil/JunitTestUtils.java
@@ -304,7 +304,7 @@ public class JunitTestUtils {
       }
     }
     List<Event> foundEvents = builder.build();
-    assertWithMessage(foundEvents.toString()).that(foundEvents).hasSize(expectedFrequency);
+    assertWithMessage(events.toString()).that(foundEvents).hasSize(expectedFrequency);
     return foundEvents;
   }
 }