Fix NPE on null body with structured message (#306)

* Fix NPE on null body with structured message

Signed-off-by: Francesco Guardiani <[email protected]>

* Improved test robustness

Signed-off-by: Francesco Guardiani <[email protected]>

Author: slinkydeveloper

core/src/main/java/io/cloudevents/core/message/impl/GenericStructuredMessageReader.java

@@ -26,8 +26,8 @@
 
 public class GenericStructuredMessageReader extends BaseStructuredMessageReader {
 
-    private EventFormat format;
-    private byte[] payload;
+    private final EventFormat format;
+    private final byte[] payload;
 
     public GenericStructuredMessageReader(EventFormat format, byte[] payload) {
         this.format = format;

http/vertx/src/main/java/io/cloudevents/http/vertx/VertxMessageFactory.java

@@ -6,8 +6,10 @@
 import io.cloudevents.core.message.impl.MessageUtils;
 import io.cloudevents.http.vertx.impl.BinaryVertxMessageReaderImpl;
 import io.cloudevents.http.vertx.impl.CloudEventsHeaders;
-import io.cloudevents.http.vertx.impl.VertxWebClientRequestMessageWriterImpl;
 import io.cloudevents.http.vertx.impl.VertxHttpServerResponseMessageWriterImpl;
+import io.cloudevents.http.vertx.impl.VertxWebClientRequestMessageWriterImpl;
+import io.cloudevents.lang.Nullable;
+import io.cloudevents.rw.CloudEventRWException;
 import io.cloudevents.rw.CloudEventWriter;
 import io.vertx.core.*;
 import io.vertx.core.buffer.Buffer;
@@ -35,12 +37,18 @@ private VertxMessageFactory() {
      * @param headers Http headers
      * @param body    nullable buffer of the body
      * @return a Message implementation with potentially an unknown encoding
-     * @throws IllegalArgumentException If, in case of binary mode, the spec version is invalid
      */
-    public static MessageReader createReader(MultiMap headers, Buffer body) throws IllegalArgumentException {
+    public static MessageReader createReader(MultiMap headers, @Nullable Buffer body) throws CloudEventRWException {
         return MessageUtils.parseStructuredOrBinaryMessage(
             () -> headers.get(HttpHeaders.CONTENT_TYPE),
-            format -> new GenericStructuredMessageReader(format, body.getBytes()),
+            format -> {
+                if (body != null) {
+                    return new GenericStructuredMessageReader(format, body.getBytes());
+                }
+                throw CloudEventRWException.newOther(new IllegalStateException(
+                    "Found a structured message using format " + format.serializedContentType() + " with null body"
+                ));
+            },
             () -> headers.get(CloudEventsHeaders.SPEC_VERSION),
             sv -> new BinaryVertxMessageReaderImpl(sv, headers, body)
         );

http/vertx/src/test/java/io/cloudevents/http/vertx/VertxMessageFactoryTest.java

@@ -22,9 +22,11 @@
 import io.cloudevents.core.message.Encoding;
 import io.cloudevents.core.message.MessageReader;
 import io.cloudevents.core.mock.CSVFormat;
+import io.cloudevents.rw.CloudEventRWException;
 import io.cloudevents.types.Time;
 import io.vertx.core.MultiMap;
 import io.vertx.core.buffer.Buffer;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -33,9 +35,22 @@
 
 import static io.cloudevents.core.test.Data.*;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
 
 public class VertxMessageFactoryTest {
 
+    @Test
+    public void structuredMessageWithoutBody() {
+        MultiMap headers = MultiMap
+            .caseInsensitiveMultiMap()
+            .add("content-type", CSVFormat.INSTANCE.serializedContentType() + "; charset=utf8");
+
+        assertThatCode(() -> VertxMessageFactory.createReader(headers, null))
+            .isInstanceOf(CloudEventRWException.class)
+            .hasCauseInstanceOf(IllegalStateException.class)
+            .hasMessageContaining("null body");
+    }
+
     @ParameterizedTest
     @MethodSource("binaryTestArguments")
     public void readBinary(MultiMap headers, Buffer body, CloudEvent event) {