Fix #387: check StreamWriteConstraints.maxNestingDepth for Avro (#663)

Author: cowtowncoder

avro/src/main/java/tools/jackson/dataformat/avro/AvroGenerator.java

@@ -315,20 +315,23 @@ protected void _closeInput() throws IOException
     @Override
     public JsonGenerator writeStartArray() throws JacksonException {
         _streamWriteContext = _streamWriteContext.createChildArrayContext(null);
+        streamWriteConstraints().validateNestingDepth(_streamWriteContext.getNestingDepth());
         _complete = false;
         return this;
     }
 
     @Override
     public JsonGenerator writeStartArray(Object currValue) throws JacksonException {
         _streamWriteContext = _streamWriteContext.createChildArrayContext(currValue);
+        streamWriteConstraints().validateNestingDepth(_streamWriteContext.getNestingDepth());
         _complete = false;
         return this;
     }
 
     @Override
     public JsonGenerator writeStartArray(Object currValue, int len) throws JacksonException {
         _streamWriteContext = _streamWriteContext.createChildArrayContext(currValue);
+        streamWriteConstraints().validateNestingDepth(_streamWriteContext.getNestingDepth());
         _complete = false;
         return this;
     }
@@ -349,13 +352,15 @@ public JsonGenerator writeEndArray() throws JacksonException
     @Override
     public JsonGenerator writeStartObject() throws JacksonException {
         _streamWriteContext = _streamWriteContext.createChildObjectContext(null);
+        streamWriteConstraints().validateNestingDepth(_streamWriteContext.getNestingDepth());
         _complete = false;
         return this;
     }
 
     @Override
     public JsonGenerator writeStartObject(Object forValue) throws JacksonException {
         _streamWriteContext = _streamWriteContext.createChildObjectContext(forValue);
+        streamWriteConstraints().validateNestingDepth(_streamWriteContext.getNestingDepth());
         _complete = false;
         return this;
     }

avro/src/test/java/module-info.java

@@ -18,6 +18,7 @@
 
     opens tools.jackson.dataformat.avro;
     opens tools.jackson.dataformat.avro.annotation;
+    opens tools.jackson.dataformat.avro.constraints;
     opens tools.jackson.dataformat.avro.dos;
     opens tools.jackson.dataformat.avro.fuzz;
     opens tools.jackson.dataformat.avro.gen;

…/avro/dos/DeepNestingAvroParserTest.java …onstraints/DeeplyNestedAvroReadTest.javaavro/src/test/java/tools/jackson/dataformat/avro/dos/DeepNestingAvroParserTest.java renamed to avro/src/test/java/tools/jackson/dataformat/avro/constraints/DeeplyNestedAvroReadTest.java avro/src/test/java/tools/jackson/dataformat/avro/dos/DeepNestingAvroParserTest.java renamed to avro/src/test/java/tools/jackson/dataformat/avro/constraints/DeeplyNestedAvroReadTest.java

@@ -1,4 +1,4 @@
-package tools.jackson.dataformat.avro.dos;
+package tools.jackson.dataformat.avro.constraints;
 
 import java.io.IOException;
 
@@ -21,7 +21,7 @@
 /**
  * Unit tests for deeply nested Documents
  */
-public class DeepNestingAvroParserTest extends AvroTestBase
+public class DeeplyNestedAvroReadTest extends AvroTestBase
 {
     protected final String NODE_SCHEMA_JSON = "{\n"
             +"\"type\": \"record\",\n"

avro/src/test/java/tools/jackson/dataformat/avro/constraints/DeeplyNestedAvroWriteTest.java

@@ -0,0 +1,60 @@
+package tools.jackson.dataformat.avro.constraints;
+
+import org.junit.jupiter.api.Test;
+
+import tools.jackson.core.StreamWriteConstraints;
+import tools.jackson.core.exc.StreamConstraintsException;
+
+import tools.jackson.dataformat.avro.*;
+
+import static org.junit.jupiter.api.Assertions.fail;
+
+/**
+ * Unit test to verify enforcement of {@code StreamWriteConstraints.maxNestingDepth}
+ * when writing Avro content.
+ */
+public class DeeplyNestedAvroWriteTest extends AvroTestBase
+{
+    public static class LinkedBean
+    {
+        LinkedBean _next;
+        final String _name;
+
+        public LinkedBean(LinkedBean next, String name) {
+            _next = next;
+            _name = name;
+        }
+
+        public LinkedBean getNext() { return _next; }
+        public String getName() { return _name; }
+
+        public void assignNext(LinkedBean n) { _next = n; }
+    }
+
+    // Unlike default depth of 1000 for other formats, use lower (400) here
+    // because we cannot actually generate 1000 levels due to Avro codec's
+    // limitations
+    private final AvroMapper MAPPER_400;
+    {
+        AvroFactory f = AvroFactory.builder()
+                .streamWriteConstraints(StreamWriteConstraints.builder().maxNestingDepth(400).build())
+                .build();
+        MAPPER_400 = new AvroMapper(f);
+    }
+
+    @Test
+    public void testTooDeepCyclic() throws Exception
+    {
+        LinkedBean beanRoot = new LinkedBean(null, "123");
+        LinkedBean bean2 = new LinkedBean(beanRoot, "456");
+        beanRoot.assignNext(bean2);
+
+        try {
+            AvroSchema schema = MAPPER_400.schemaFor(LinkedBean.class);
+            MAPPER_400.writer(schema).writeValueAsBytes(beanRoot);
+            fail("expected StreamConstraintsException");
+        } catch (StreamConstraintsException e) {
+            verifyException(e, "Document nesting depth");
+        }
+    }
+}

avro/src/test/java/tools/jackson/dataformat/avro/dos/CyclicAvroDataSerTest.java

@@ -2,84 +2,46 @@
 
 import org.junit.jupiter.api.Test;
 
-import tools.jackson.core.StreamReadConstraints;
 import tools.jackson.databind.exc.InvalidDefinitionException;
 
 import tools.jackson.dataformat.avro.*;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 
 /**
- * Simple unit tests to verify that we fail gracefully if you attempt to serialize
- * data that is cyclic (eg a list that contains itself).
+ * Simple unit test to verify that we fail gracefully if you attempt to serialize
+ * data that is directly cyclic (eg a list that contains itself).
  */
 public class CyclicAvroDataSerTest extends AvroTestBase
 {
-
-    public static class Bean
+    public static class LinkedBean
     {
-        Bean _next;
+        LinkedBean _next;
         final String _name;
 
-        public Bean(Bean next, String name) {
+        public LinkedBean(LinkedBean next, String name) {
             _next = next;
             _name = name;
         }
 
-        public Bean getNext() { return _next; }
+        public LinkedBean getNext() { return _next; }
         public String getName() { return _name; }
 
-        public void assignNext(Bean n) { _next = n; }
+        public void assignNext(LinkedBean n) { _next = n; }
     }
 
     private final AvroMapper MAPPER = getMapper();
 
-    // Unlike default depth of 1000 for other formats, use lower (400) here
-    // because we cannot actually generate 1000 levels due to Avro codec's
-    // limitations
-    private final AvroMapper MAPPER_400;
-    {
-        AvroFactory f = AvroFactory.builder()
-                .streamReadConstraints(StreamReadConstraints.builder().maxNestingDepth(400).build())
-                .build();
-        MAPPER_400 = new AvroMapper(f);
-    }
-
     @Test
     public void testDirectCyclic() throws Exception {
-        Bean bean = new Bean(null, "123");
+        LinkedBean bean = new LinkedBean(null, "123");
         bean.assignNext(bean);
         try {
-            AvroSchema schema = MAPPER.schemaFor(Bean.class);
+            AvroSchema schema = MAPPER.schemaFor(LinkedBean.class);
             MAPPER.writer(schema).writeValueAsBytes(bean);
             fail("expected InvalidDefinitionException");
-        } catch (InvalidDefinitionException idex) {
-            assertTrue(idex.getMessage().startsWith("Direct self-reference leading to cycle"),
-                    "InvalidDefinitionException message is as expected?");
-        }
-    }
-
-    // With 2.16 also test looser loops, wrt new limits
-    @Test
-    public void testLooserCyclic() throws Exception
-    {
-        Bean beanRoot = new Bean(null, "123");
-        Bean bean2 = new Bean(beanRoot, "456");
-        beanRoot.assignNext(bean2);
-
-        // 12-Jul-2023, tatu: Alas, won't work -- Avro serialization by-passes many
-        //    checks. Needs more work in future
-
-        if (false) {
-            try {
-                AvroSchema schema = MAPPER_400.schemaFor(Bean.class);
-                MAPPER_400.writer(schema).writeValueAsBytes(beanRoot);
-                fail("expected InvalidDefinitionException");
-            } catch (InvalidDefinitionException idex) {
-                assertTrue(idex.getMessage().startsWith("Direct self-reference leading to cycle"),
-                        "InvalidDefinitionException message is as expected?");
-            }
+        } catch (InvalidDefinitionException e) {
+            verifyException(e, "Direct self-reference leading to cycle");
         }
     }
 }

release-notes/VERSION

@@ -14,6 +14,10 @@ implementations)
 === Releases ===
 ------------------------------------------------------------------------
 
+3.1.1 (not yet released)
+
+#387: Avro generator should enforce `StreamWriteConstraints.maxNestingDepth`
+
 3.1.0 (23-Feb-2026)
 
 #73: (protobuf) Cannot resolve inner types in protoc definitions