Resolve map(varchar, json) canonicalization bug

The map function will not sort a json object by its keys, despite the
json_parse function sorting the same input.
If implemented, this will sort json objects.

Resolves prestodb#24207

presto-main/src/main/java/com/facebook/presto/util/JsonUtil.java

@@ -38,7 +38,10 @@
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.core.TreeNode;
+import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.primitives.Shorts;
 import com.google.common.primitives.SignedBytes;
 import io.airlift.slice.Slice;
@@ -53,6 +56,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -86,6 +90,7 @@
 import static com.fasterxml.jackson.core.JsonToken.FIELD_NAME;
 import static com.fasterxml.jackson.core.JsonToken.START_ARRAY;
 import static com.fasterxml.jackson.core.JsonToken.START_OBJECT;
+import static com.fasterxml.jackson.databind.SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Verify.verify;
 import static it.unimi.dsi.fastutil.HashCommon.arraySize;
@@ -102,10 +107,8 @@ public final class JsonUtil
 {
     public static final JsonFactory JSON_FACTORY = new JsonFactory().disable(CANONICALIZE_FIELD_NAMES);
 
-    // This object mapper is constructed without .configure(ORDER_MAP_ENTRIES_BY_KEYS, true) because
-    // `OBJECT_MAPPER.writeValueAsString(parser.readValueAsTree());` preserves input order.
     // Be aware. Using it arbitrarily can produce invalid json (ordered by key is required in Presto).
-    private static final ObjectMapper OBJECT_MAPPED_UNORDERED = new ObjectMapper(JSON_FACTORY);
+    private static final ObjectMapper OBJECT_MAPPED_ORDERED = new ObjectMapper(JSON_FACTORY).configure(ORDER_MAP_ENTRIES_BY_KEYS, true);
 
     private static final int MAX_JSON_LENGTH_IN_ERROR_MESSAGE = 10_000;
 
@@ -956,7 +959,18 @@ static BlockBuilderAppender createBlockBuilderAppender(Type type)
                     return new VarcharBlockBuilderAppender(type);
                 case StandardTypes.JSON:
                     return (parser, blockBuilder, sqlFunctionProperties) -> {
-                        String json = OBJECT_MAPPED_UNORDERED.writeValueAsString(parser.readValueAsTree());
+                        TreeNode obj = parser.readValueAsTree();
+                        String json = "";
+                        if (obj instanceof ObjectNode) {
+                            Map<String, JsonNode> recreatedChildren = new LinkedHashMap<>();
+                            ((ObjectNode) obj).fields().forEachRemaining(entry -> {
+                                recreatedChildren.put(entry.getKey(), entry.getValue());
+                            });
+                            json = OBJECT_MAPPED_ORDERED.writeValueAsString(recreatedChildren);
+                        }
+                        else {
+                            json = OBJECT_MAPPED_ORDERED.writeValueAsString(obj);
+                        }
                         JSON.writeSlice(blockBuilder, Slices.utf8Slice(json));
                     };
                 case StandardTypes.ARRAY:
@@ -1165,6 +1179,7 @@ public void append(JsonParser parser, BlockBuilder blockBuilder, SqlFunctionProp
                 throws IOException
         {
             Slice result = currentTokenAsVarchar(parser);
+            String s = result.toStringUtf8();
             if (result == null) {
                 blockBuilder.appendNull();
             }

presto-main/src/test/java/com/facebook/presto/operator/TestMapVarcharJsonOperator.java

@@ -0,0 +1,59 @@
+package com.facebook.presto.operator;
+
+import com.facebook.presto.Session;
+import com.facebook.presto.testing.LocalQueryRunner;
+import com.facebook.presto.testing.MaterializedResult;
+import com.facebook.presto.testing.MaterializedRow;
+import com.facebook.presto.testing.QueryRunner;
+import com.google.common.collect.Iterables;
+import org.intellij.lang.annotations.Language;
+import org.testng.annotations.AfterClass;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static com.facebook.presto.testing.TestingSession.testSessionBuilder;
+import static java.lang.String.format;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+public class TestMapVarcharJsonOperator
+{
+    private QueryRunner queryRunner;
+    @BeforeClass
+    public void setUp()
+    {
+        Session session = testSessionBuilder().build();
+        this.queryRunner = new LocalQueryRunner(session);
+    }
+
+    @AfterClass(alwaysRun = true)
+    public void tearDown()
+    {
+        queryRunner.close();
+        queryRunner = null;
+    }
+
+    @Test
+    public void testFunction()
+    {
+        Map<String, String> map = new HashMap<>();
+        map.put("m", "[\"rn\",\"w\",\"a\"]");
+        assertThatQueryReturnsValue("SELECT TRY(CAST(json_parse(c0) AS map(varchar, json))) from (values ('{\"m\": [\"rn\", \"w\", \"a\"]}')) t(c0)", map);
+        map.put("m", "{\"pl\":\"4\",\"rn\":\"w\"}");
+        assertThatQueryReturnsValue("SELECT TRY(CAST(json_parse(c0) AS map(varchar, json))) from (values ('{\"m\": {\"rn\": \"w\", \"pl\": \"4\"}}')) t(c0)", map);
+    }
+
+    private void assertThatQueryReturnsValue(@Language("SQL") String sql, Object expected)
+    {
+        MaterializedResult rows = queryRunner.execute(sql);
+        MaterializedRow materializedRow = Iterables.getOnlyElement(rows);
+        int fieldCount = materializedRow.getFieldCount();
+        assertTrue(fieldCount == 1, format("Expected only one column, but got '%d'", fieldCount));
+        Object value = materializedRow.getField(0);
+        assertEquals(value, expected);
+        assertTrue(Iterables.getOnlyElement(rows).getFieldCount() == 1);
+    }
+}