Adding Duplicate key check in JacksonJrsTreeCodec (#127)

jr-stree/src/main/java/com/fasterxml/jackson/jr/stree/JacksonJrsTreeCodec.java

@@ -4,6 +4,7 @@
 import java.util.*;
 
 import com.fasterxml.jackson.core.*;
+import com.fasterxml.jackson.jr.ob.JSONObjectException;
 
 /**
  * {@link TreeCodec} implementation that can build "simple", immutable
@@ -13,9 +14,6 @@
 public class JacksonJrsTreeCodec extends TreeCodec
 {
     public static JrsMissing MISSING = JrsMissing.instance;
-
-    public static final JacksonJrsTreeCodec SINGLETON = new JacksonJrsTreeCodec();
-
     protected final ObjectCodec _objectCodec;
 
     // @since 2.17
@@ -44,7 +42,7 @@ private JrsValue nodeFrom(JsonParser p) throws IOException
     {
         int tokenId = p.hasCurrentToken()
                 ? p.currentTokenId() : p.nextToken().id();
-        
+
         switch (tokenId) {
         case JsonTokenId.ID_TRUE:
             return JrsBoolean.TRUE;
@@ -55,24 +53,25 @@ private JrsValue nodeFrom(JsonParser p) throws IOException
             return new JrsNumber(p.getNumberValue());
         case JsonTokenId.ID_STRING:
             return new JrsString(p.getText());
-        case JsonTokenId.ID_START_ARRAY:
-            {
-                List<JrsValue> values = _list();
-                while (p.nextToken() != JsonToken.END_ARRAY) {
-                    values.add(nodeFrom(p));
-                }
-                return new JrsArray(values);
+        case JsonTokenId.ID_START_ARRAY: {
+            List<JrsValue> values = _list();
+            while (p.nextToken() != JsonToken.END_ARRAY) {
+                values.add(nodeFrom(p));
             }
-        case JsonTokenId.ID_START_OBJECT:
-            {
-                Map<String, JrsValue> values = _map();
-                while (p.nextToken() != JsonToken.END_OBJECT) {
-                    final String currentName = p.currentName();
-                    p.nextToken();
-                    values.put(currentName, nodeFrom(p));
+            return new JrsArray(values);
+        }
+        case JsonTokenId.ID_START_OBJECT: {
+            Map<String, JrsValue> values = _map();
+            while (p.nextToken() != JsonToken.END_OBJECT) {
+                final String currentName = p.currentName();
+                p.nextToken();
+                JrsValue prev = values.put(currentName, nodeFrom(p));
+                if (_failOnDuplicateKeys && (prev != null)) {
+                    throw new JSONObjectException("Duplicate key (key '" + currentName + "')");
                 }
-                return new JrsObject(values);
             }
+            return new JrsObject(values);
+        }
         case JsonTokenId.ID_EMBEDDED_OBJECT:
             // 07-Jan-2016, tatu: won't happen with JSON, but other types like Smile
             //   may produce binary data or such
@@ -82,7 +81,7 @@ private JrsValue nodeFrom(JsonParser p) throws IOException
             return JrsNull.instance;
         default:
         }
-        throw new UnsupportedOperationException("Unsupported token id "+tokenId+" ("+p.currentToken()+")");
+        throw new UnsupportedOperationException("Unsupported token id " + tokenId + " (" + p.currentToken() + ")");
     }
 
     @Override
@@ -134,7 +133,7 @@ public JsonParser treeAsTokens(TreeNode node) {
      * @since 2.8
      */
     public JrsBoolean booleanNode(boolean state) {
-         return state? JrsBoolean.TRUE : JrsBoolean.FALSE;
+        return state ? JrsBoolean.TRUE : JrsBoolean.FALSE;
     }
 
     /**

jr-stree/src/test/java/com/fasterxml/jackson/jr/stree/DupFieldNameInTree51Test.java

@@ -0,0 +1,38 @@
+package com.fasterxml.jackson.jr.stree;
+
+import com.fasterxml.jackson.jr.ob.JSON;
+import com.fasterxml.jackson.jr.ob.JSONObjectException;
+
+/**
+ * Tests for reading content using {@link JSON} with proper
+ * codec registration
+ */
+public class DupFieldNameInTree51Test extends JacksonJrTreeTestBase
+{
+    private final JSON NO_DUPS_JSON = JSON.builder()
+            .enable(JSON.Feature.FAIL_ON_DUPLICATE_MAP_KEYS)
+            .register(new JrSimpleTreeExtension())
+            .build();
+
+    private final JSON DUPS_OK_JSON = JSON.builder()
+            .disable(JSON.Feature.FAIL_ON_DUPLICATE_MAP_KEYS)
+            .register(new JrSimpleTreeExtension())
+            .build();
+
+    // [jackson-jr#51]: test dup keys for trees too
+    public void testFailOnDupMapKeys() throws Exception
+    {
+        assertTrue(NO_DUPS_JSON.isEnabled(JSON.Feature.FAIL_ON_DUPLICATE_MAP_KEYS));
+        final String json = "{\"a\":1,\"b\":2,\"b\":3,\"c\":4}";
+        try {
+            /*TreeNode node =*/ NO_DUPS_JSON.treeFrom(json);
+            fail("Should not pass");
+        } catch (JSONObjectException e) {
+            verifyException(e, "Duplicate key");
+        }
+
+        assertFalse(DUPS_OK_JSON.isEnabled(JSON.Feature.FAIL_ON_DUPLICATE_MAP_KEYS));
+        // But should pass fine without setting
+        assertNotNull(DUPS_OK_JSON.treeFrom(json));
+    }
+}

jr-stree/src/test/java/com/fasterxml/jackson/jr/stree/JacksonJrTreeTestBase.java

@@ -49,6 +49,6 @@ protected JSON jsonWithTreeCodec() {
                 // 13-Feb-2020, tatu: There are 2 different ways actually..
 //            .treeCodec(new JacksonJrsTreeCodec())
                 .register(new JrSimpleTreeExtension())
-            .build();
+                .build();
     }
 }

release-notes/CREDITS-2.x

@@ -52,6 +52,8 @@ Julian Honnen (@jhonnen)
  (2.17.0)
 * Contributed PoC of #25: Add support single-int Constructors
  (2.17.0)
+* Contributed #51: Duplicate key detection does not work for (simple) Trees
+ (2.17.0)
 * Contributed fix for #93: Skip serialization of `groovy.lang.MetaClass` values
   to avoid `StackOverflowError`
  (2.17.0)

release-notes/VERSION-2.x

@@ -15,6 +15,8 @@ Not yet released
 
 #7: Support deserialization of `int[]`
  (contributed by @Shounaks) 
+#51: Duplicate key detection does not work for (simple) Trees
+ (contributed by @Shounaks) 
 #131: Add mechanism for `JacksonJrExtension`s to access state of `JSON.Feature`s
 
 2.17.0-rc1 (26-Feb-2024)