Fix #5344: JsonParser.readValueAs(), end-of-input

release-notes/CREDITS

@@ -83,3 +83,7 @@ Artur (@Artur-)
 Dónal Murtagh (@donalmurtagh)
  * Reported #5323: `UUID` serialization is broken in v3.0.0-rc9
   [3.0.0]
+
+Phil Clay (@philsttr)
+ * Reported #5344: "Unexpected end-of-input" for `JsonParser.readValueAs()` (in 3.0)
+  [3.0.1]

release-notes/VERSION

@@ -10,6 +10,8 @@ Versions: 3.x (for earlier see VERSION-2.x)
 #5340: `DeserializationFeature.ACCEPT_FLOAT_AS_INT` not respected for byte/short
   when deserializing from JsonNode
  (reported by @Artur)
+#5344: "Unexpected end-of-input" for `JsonParser.readValueAs()` (in 3.0)
+ (reported by Phil C)
 
 3.0.0 (03-Oct-2025)
 

src/main/java/tools/jackson/databind/DeserializationContext.java

@@ -397,6 +397,10 @@ public <T> T readValue(JsonParser p, JavaType type) throws JacksonException {
      */
     private Object _readValue(JsonParser p, ValueDeserializer<Object> deser) throws JacksonException
     {
+        // 12-Oct-2025, tatu: As per [databind#5344], need to ensure parser points to token
+        if (!p.hasCurrentToken()) {
+            p.nextToken();
+        }
         if (p.hasToken(JsonToken.VALUE_NULL)) {
              return deser.getNullValue(this);
         }

src/test/java/tools/jackson/databind/MapperViaParserTest.java

@@ -1,19 +1,17 @@
 package tools.jackson.databind;
 
-import java.io.StringReader;
-
 import org.junit.jupiter.api.Test;
 
 import tools.jackson.core.*;
 import tools.jackson.core.io.CharacterEscapes;
 import tools.jackson.core.io.SerializedString;
 import tools.jackson.core.json.JsonFactory;
 import tools.jackson.core.json.JsonWriteFeature;
+import tools.jackson.core.type.TypeReference;
+import tools.jackson.databind.json.JsonMapper;
 import tools.jackson.databind.testutil.DatabindTestUtil;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-
 
 public class MapperViaParserTest
     extends DatabindTestUtil
@@ -24,7 +22,7 @@ public class MapperViaParserTest
     final static SerializedString TWO_BYTE_ESCAPED_STRING = new SerializedString("&111;");
     final static SerializedString THREE_BYTE_ESCAPED_STRING = new SerializedString("&1111;");
 
-    final static class Pojo
+    static class Pojo
     {
         int _x;
 
@@ -82,22 +80,51 @@ public SerializableString getEscapeSequence(int ch)
 
     private final ObjectMapper MAPPER = newJsonMapper();
 
-    @SuppressWarnings("resource")
     @Test
-    public void testPojoReadingOk() throws Exception
+    public void testPojoReadingOkClass() throws Exception
+    {
+        try (JsonParser p = MAPPER.createParser(a2q("{ 'x' : 9 }"))) {
+            Pojo pojo = p.readValueAs(Pojo.class);
+            assertEquals(9, pojo._x);
+        }
+    }
+
+    @Test
+    public void testPojoReadingOkTypeRef() throws Exception
+    {
+        try (JsonParser p = MAPPER.createParser(a2q("{ 'x' : 7 }"))) {
+            Pojo pojo = p.readValueAs(new TypeReference<Pojo>() { });
+            assertEquals(7, pojo._x);
+        }
+    }
+
+    @Test
+    public void testPojoReadingOkJavaType() throws Exception
     {
-        final String JSON = "{ \"x\" : 9 }";
-        JsonParser jp = MAPPER.createParser(new StringReader(JSON));
-        jp.nextToken();
-        Pojo p = jp.readValueAs(Pojo.class);
-        assertNotNull(p);
+        try (JsonParser p = MAPPER.createParser(a2q("{ 'x' : 42 }"))) {
+            Pojo pojo = p.readValueAs(MAPPER.constructType(Pojo.class));
+            assertEquals(42, pojo._x);
+        }
+    }
+
+    @Test
+    public void testTreeReadingOk() throws Exception
+    {
+        final String JSON = a2q("{ 'x' : 9 }");
+        try (JsonParser p = MAPPER.createParser(JSON)) {
+            JsonNode tree = p.readValueAsTree();
+            assertEquals(MAPPER.createObjectNode().put("x", 9), tree);
+        }
     }
 
+    // // // Misc other tests
+
     @Test
     public void testEscapingUsingMapper() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper(JsonFactory.builder()
-                .enable(JsonWriteFeature.ESCAPE_NON_ASCII).build());
+        ObjectMapper mapper = JsonMapper.builder(JsonFactory.builder()
+                .enable(JsonWriteFeature.ESCAPE_NON_ASCII).build())
+                .build();
         final String json = mapper.writeValueAsString(String.valueOf((char) 258));
         assertEquals(q("\\u0102"), json);
     }

src/test/java/tools/jackson/databind/ObjectMapperTest.java

@@ -4,7 +4,6 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.*;
 import java.util.*;
-import java.util.stream.Collectors;
 import java.util.zip.ZipOutputStream;
 
 import org.junit.jupiter.api.Test;
@@ -249,7 +248,6 @@ public void testDataInputViaMapper() throws Exception
         assertNotNull(n);
     }
 
-    @SuppressWarnings("serial")
     @Test
     public void testRegisterDependentModules() {