added extra checks in SectionAcknowledgmentTest

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-http3/http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/SectionAcknowledgmentTest.java

@@ -15,6 +15,7 @@
 
 import java.nio.ByteBuffer;
 
+import org.eclipse.jetty.http3.qpack.QpackException.SessionException;
 import org.eclipse.jetty.http3.qpack.internal.instruction.SectionAcknowledgmentInstruction;
 import org.eclipse.jetty.util.BufferUtil;
 import org.junit.jupiter.api.BeforeEach;
@@ -25,6 +26,8 @@
 import static org.eclipse.jetty.http3.qpack.QpackTestUtil.toMetaData;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -68,12 +71,13 @@ public void testSectionAcknowledgmentForZeroRequiredInsertCountOnEncoder() throw
     {
         // Encode a header with only a value contained in the static table.
         ByteBuffer buffer = encode(_encoder, 0, toMetaData("GET", "/", "http"));
-        System.err.println(BufferUtil.toDetailString(buffer));
+        assertThat(BufferUtil.remaining(buffer), greaterThan(0L));
 
         // Parsing a section ack instruction on the encoder when we are not expecting it should result in QPACK_DECODER_STREAM_ERROR.
         SectionAcknowledgmentInstruction instruction = new SectionAcknowledgmentInstruction(0);
         ByteBuffer instructionBuffer = toBuffer(instruction);
-        QpackException error = assertThrows(QpackException.class, () -> _encoder.parseInstructions(instructionBuffer));
+        SessionException error = assertThrows(SessionException.class, () -> _encoder.parseInstructions(instructionBuffer));
+        assertThat(error.getErrorCode(), equalTo(QpackException.QPACK_ENCODER_STREAM_ERROR));
         assertThat(error.getMessage(), containsString("No StreamInfo for 0"));
     }
 }