T-3396 Keep sending the batch when an event can't provide caller data

src/main/java/com/logtail/logback/LogtailAppender.java

@@ -309,17 +309,22 @@ protected Map<String, Object> generateLogRuntime(ILoggingEvent event) {
         Map<String, Object> logRuntime = new HashMap<>();
         logRuntime.put("thread", event.getThreadName());
 
-        if (event.hasCallerData()) {
-            StackTraceElement[] callerData = event.getCallerData();
+        try {
+            if (event.hasCallerData()) {
+                StackTraceElement[] callerData = event.getCallerData();
 
-            if (callerData.length > 0) {
-                StackTraceElement callerContext = callerData[0];
+                if (callerData.length > 0) {
+                    StackTraceElement callerContext = callerData[0];
 
-                logRuntime.put("class", callerContext.getClassName());
-                logRuntime.put("method", callerContext.getMethodName());
-                logRuntime.put("file", callerContext.getFileName());
-                logRuntime.put("line", callerContext.getLineNumber());
+                    logRuntime.put("class", callerContext.getClassName());
+                    logRuntime.put("method", callerContext.getMethodName());
+                    logRuntime.put("file", callerContext.getFileName());
+                    logRuntime.put("line", callerContext.getLineNumber());
+                }
             }
+        } catch (RuntimeException e) {
+            // Caller data is optional and some ILoggingEvent implementations fail to compute it, e.g. the Quarkus
+            // logback bridge on a log record without a source class - the line is still worth sending without it
         }
 
         return logRuntime;

src/test/java/com/logtail/logback/LogtailAppenderCallerDataTest.java

@@ -0,0 +1,44 @@
+package com.logtail.logback;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.LoggerContext;
+import ch.qos.logback.classic.spi.LoggingEvent;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Caller data is optional in the payload, so an event that cannot provide it must not take the whole batch down.
+ */
+public class LogtailAppenderCallerDataTest {
+
+    @Test
+    public void testBatchStillSerializesWhenAnEventThrowsFromHasCallerData() throws Exception {
+        Logger logger = new LoggerContext().getLogger(Logger.ROOT_LOGGER_NAME);
+        LogtailAppender appender = new LogtailAppender();
+        appender.batch.add(new LoggingEvent(Logger.FQCN, logger, Level.INFO, "Regular event", null, new Object[]{}));
+        appender.batch.add(new LoggingEvent(Logger.FQCN, logger, Level.INFO, "Event whose caller data throws", null, new Object[]{}) {
+            // The Quarkus logback bridge (io.quarkiverse.logback.runtime.LoggingEventWrapper) rebuilds caller data
+            // from the JBoss log record inside hasCallerData() and throws when the record carries no source class
+            @Override
+            public boolean hasCallerData() {
+                throw new NullPointerException("Declaring class is null");
+            }
+        });
+
+        List<Map<String, Object>> lines = new ObjectMapper().readValue(appender.batchToJson(2), new TypeReference<List<Map<String, Object>>>() {});
+
+        assertEquals(Arrays.asList("Regular event", "Event whose caller data throws"),
+                lines.stream().map(line -> line.get("message")).collect(Collectors.toList()));
+        assertEquals(Collections.singletonMap("thread", "main"), lines.get(1).get("runtime"));
+    }
+}