Fix exception message handling to prevent empty message field in Application Insights telemetry

settings.gradle.kts

@@ -77,6 +77,7 @@ hideFromDependabot(":smoke-tests:apps:CoreAndFilter3xUsingOld3xAgent")
 hideFromDependabot(":smoke-tests:apps:CustomDimensions")
 hideFromDependabot(":smoke-tests:apps:CustomInstrumentation")
 hideFromDependabot(":smoke-tests:apps:DetectUnexpectedOtelMetrics")
+hideFromDependabot(":smoke-tests:apps:ExceptionMessageHandling")
 hideFromDependabot(":smoke-tests:apps:Diagnostics")
 hideFromDependabot(":smoke-tests:apps:Diagnostics:JfrFileReader")
 hideFromDependabot(":smoke-tests:apps:DiagnosticExtension:MockExtension")

smoke-tests/apps/ExceptionMessageHandling/build.gradle.kts

@@ -0,0 +1,11 @@
+plugins {
+  id("ai.smoke-test-war")
+}
+
+dependencies {
+  implementation("org.springframework.boot:spring-boot-starter-web:2.5.12") {
+    exclude("org.springframework.boot", "spring-boot-starter-tomcat")
+  }
+  // this dependency is needed to make wildfly happy
+  implementation("org.reactivestreams:reactive-streams:1.0.3")
+}

smoke-tests/apps/ExceptionMessageHandling/src/main/java/com/microsoft/applicationinsights/smoketestapp/SpringBootApp.java

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.applicationinsights.smoketestapp;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+@SpringBootApplication
+public class SpringBootApp extends SpringBootServletInitializer {
+  @Override
+  protected SpringApplicationBuilder configure(SpringApplicationBuilder applicationBuilder) {
+    return applicationBuilder.sources(SpringBootApp.class);
+  }
+}

smoke-tests/apps/ExceptionMessageHandling/src/main/java/com/microsoft/applicationinsights/smoketestapp/TestController.java

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.applicationinsights.smoketestapp;
+
+import javax.servlet.http.HttpServletResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class TestController {
+
+  private static final Logger logger = LoggerFactory.getLogger("smoketestapp");
+
+  @GetMapping("/")
+  public String root() {
+    return "OK";
+  }
+
+  @GetMapping("/testExceptionWithoutMessage")
+  public String testExceptionWithoutMessage(HttpServletResponse response) {
+    // This reproduces the original issue: exceptions without messages
+    // that would cause 206 errors from Application Insights service
+    logger.error("Exception without message test", new NullPointerException());
+    return "Exception logged";
+  }
+
+  @GetMapping("/testExceptionWithEmptyMessage")
+  public String testExceptionWithEmptyMessage(HttpServletResponse response) {
+    // Test exception with empty message
+    logger.error("Exception with empty message test", new RuntimeException(""));
+    return "Exception logged";
+  }
+
+  @GetMapping("/testExceptionWithWhitespaceMessage")
+  public String testExceptionWithWhitespaceMessage(HttpServletResponse response) {
+    // Test exception with whitespace-only message
+    logger.error("Exception with whitespace message test", new IllegalArgumentException("   "));
+    return "Exception logged";
+  }
+}

smoke-tests/apps/ExceptionMessageHandling/src/smokeTest/java/com/microsoft/applicationinsights/smoketest/ExceptionMessageHandlingTest.java

@@ -0,0 +1,100 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.applicationinsights.smoketest;
+
+import static com.microsoft.applicationinsights.smoketest.EnvironmentValue.TOMCAT_8_JAVA_11;
+import static com.microsoft.applicationinsights.smoketest.EnvironmentValue.TOMCAT_8_JAVA_17;
+import static com.microsoft.applicationinsights.smoketest.EnvironmentValue.TOMCAT_8_JAVA_21;
+import static com.microsoft.applicationinsights.smoketest.EnvironmentValue.TOMCAT_8_JAVA_8;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.microsoft.applicationinsights.smoketest.schemav2.Data;
+import com.microsoft.applicationinsights.smoketest.schemav2.Envelope;
+import com.microsoft.applicationinsights.smoketest.schemav2.ExceptionData;
+import com.microsoft.applicationinsights.smoketest.schemav2.SeverityLevel;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+@UseAgent
+abstract class ExceptionMessageHandlingTest {
+
+  @RegisterExtension static final SmokeTestExtension testing = SmokeTestExtension.create();
+
+  @Test
+  @TargetUri("/testExceptionWithoutMessage")
+  void testExceptionWithoutMessage() throws Exception {
+    List<Envelope> rdList = testing.mockedIngestion.waitForItems("RequestData", 1);
+
+    Envelope rdEnvelope = rdList.get(0);
+    String operationId = rdEnvelope.getTags().get("ai.operation.id");
+    List<Envelope> edList =
+        testing.mockedIngestion.waitForItemsInOperation("ExceptionData", 1, operationId);
+
+    Envelope edEnvelope = edList.get(0);
+    ExceptionData ed = (ExceptionData) ((Data<?>) edEnvelope.getData()).getBaseData();
+
+    // Verify that exceptions without messages have their class name as the message
+    // This prevents the 206 error: "Field 'message' on type 'ExceptionDetails' is required but
+    // missing or empty"
+    assertThat(ed.getExceptions().get(0).getTypeName()).isEqualTo("java.lang.NullPointerException");
+    assertThat(ed.getExceptions().get(0).getMessage()).isEqualTo("java.lang.NullPointerException");
+    assertThat(ed.getExceptions().get(0).getMessage()).isNotEmpty();
+    assertThat(ed.getSeverityLevel()).isEqualTo(SeverityLevel.ERROR);
+  }
+
+  @Test
+  @TargetUri("/testExceptionWithEmptyMessage")
+  void testExceptionWithEmptyMessage() throws Exception {
+    List<Envelope> rdList = testing.mockedIngestion.waitForItems("RequestData", 1);
+
+    Envelope rdEnvelope = rdList.get(0);
+    String operationId = rdEnvelope.getTags().get("ai.operation.id");
+    List<Envelope> edList =
+        testing.mockedIngestion.waitForItemsInOperation("ExceptionData", 1, operationId);
+
+    Envelope edEnvelope = edList.get(0);
+    ExceptionData ed = (ExceptionData) ((Data<?>) edEnvelope.getData()).getBaseData();
+
+    // Verify that exceptions with empty messages have their class name as the message
+    assertThat(ed.getExceptions().get(0).getTypeName()).isEqualTo("java.lang.RuntimeException");
+    assertThat(ed.getExceptions().get(0).getMessage()).isEqualTo("java.lang.RuntimeException");
+    assertThat(ed.getExceptions().get(0).getMessage()).isNotEmpty();
+    assertThat(ed.getSeverityLevel()).isEqualTo(SeverityLevel.ERROR);
+  }
+
+  @Test
+  @TargetUri("/testExceptionWithWhitespaceMessage")
+  void testExceptionWithWhitespaceMessage() throws Exception {
+    List<Envelope> rdList = testing.mockedIngestion.waitForItems("RequestData", 1);
+
+    Envelope rdEnvelope = rdList.get(0);
+    String operationId = rdEnvelope.getTags().get("ai.operation.id");
+    List<Envelope> edList =
+        testing.mockedIngestion.waitForItemsInOperation("ExceptionData", 1, operationId);
+
+    Envelope edEnvelope = edList.get(0);
+    ExceptionData ed = (ExceptionData) ((Data<?>) edEnvelope.getData()).getBaseData();
+
+    // Verify that exceptions with whitespace-only messages have their class name as the message
+    assertThat(ed.getExceptions().get(0).getTypeName())
+        .isEqualTo("java.lang.IllegalArgumentException");
+    assertThat(ed.getExceptions().get(0).getMessage())
+        .isEqualTo("java.lang.IllegalArgumentException");
+    assertThat(ed.getExceptions().get(0).getMessage()).isNotEmpty();
+    assertThat(ed.getSeverityLevel()).isEqualTo(SeverityLevel.ERROR);
+  }
+
+  @Environment(TOMCAT_8_JAVA_8)
+  static class Tomcat8Java8Test extends ExceptionMessageHandlingTest {}
+
+  @Environment(TOMCAT_8_JAVA_11)
+  static class Tomcat8Java11Test extends ExceptionMessageHandlingTest {}
+
+  @Environment(TOMCAT_8_JAVA_17)
+  static class Tomcat8Java17Test extends ExceptionMessageHandlingTest {}
+
+  @Environment(TOMCAT_8_JAVA_21)
+  static class Tomcat8Java21Test extends ExceptionMessageHandlingTest {}
+}