Ensure double values stay double even if they fit in an integer (#289)

Author: swallez

java-client/src/main/java/co/elastic/clients/json/jackson/JsonValueParser.java

@@ -24,13 +24,16 @@
 import com.fasterxml.jackson.core.JsonToken;
 import jakarta.json.JsonArray;
 import jakarta.json.JsonArrayBuilder;
+import jakarta.json.JsonNumber;
 import jakarta.json.JsonObject;
 import jakarta.json.JsonObjectBuilder;
 import jakarta.json.JsonValue;
 import jakarta.json.spi.JsonProvider;
 import jakarta.json.stream.JsonParsingException;
 
 import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.BigInteger;
 
 /**
  * Reads a Jsonp value/object/array from a Jackson parser. The parser's current token should be the start of the
@@ -65,6 +68,7 @@ public JsonArray parseArray(JsonParser parser) throws IOException {
     }
 
     public JsonValue parseValue(JsonParser parser) throws IOException {
+        JsonToken jsonToken = parser.currentToken();
         switch (parser.currentToken()) {
             case START_OBJECT:
                 return parseObject(parser);
@@ -93,7 +97,8 @@ public JsonValue parseValue(JsonParser parser) throws IOException {
                         return provider.createValue(parser.getLongValue());
                     case FLOAT:
                     case DOUBLE:
-                        return provider.createValue(parser.getDoubleValue());
+                        // Use double also for floats, as JSON-P has no support for float
+                        return new DoubleNumber(parser.getDoubleValue());
                     case BIG_DECIMAL:
                         return provider.createValue(parser.getDecimalValue());
                     case BIG_INTEGER:
@@ -105,4 +110,95 @@ public JsonValue parseValue(JsonParser parser) throws IOException {
 
         }
     }
+
+    private static class DoubleNumber implements JsonNumber {
+
+        private final double value;
+
+        DoubleNumber(double value) {
+            this.value = value;
+        }
+
+        @Override
+        public boolean isIntegral() {
+            return false;
+        }
+
+        @Override
+        public int intValue() {
+            return (int) value;
+        }
+
+        @Override
+        public int intValueExact() {
+            int result = (int) value;
+
+            if ((double)result == value) {
+                return result;
+            } else {
+                throw new ArithmeticException();
+            }
+        }
+
+        @Override
+        public long longValue() {
+            return (long) value;
+        }
+
+        @Override
+        public long longValueExact() {
+            long result = (long) value;
+
+            if ((double)result == value) {
+                return result;
+            } else {
+                throw new ArithmeticException();
+            }
+        }
+
+        @Override
+        public BigInteger bigIntegerValue() {
+            return bigDecimalValue().toBigInteger();
+        }
+
+        @Override
+        public BigInteger bigIntegerValueExact() {
+            return bigDecimalValue().toBigIntegerExact();
+        }
+
+        @Override
+        public double doubleValue() {
+            return value;
+        }
+
+        @Override
+        public BigDecimal bigDecimalValue() {
+            return new BigDecimal(value);
+        }
+
+        @Override
+        public ValueType getValueType() {
+            return ValueType.NUMBER;
+        }
+
+        @Override
+        public Number numberValue() {
+            return value;
+        }
+
+        @Override
+        public String toString() {
+            return String.valueOf(value);
+        }
+
+        @Override
+        public int hashCode() {
+            return Double.hashCode(value);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            return obj instanceof DoubleNumber && ((DoubleNumber)obj).value == value;
+        }
+    }
 }

java-client/src/test/java/co/elastic/clients/elasticsearch/json/jackson/JsonValueParserTest.java

@@ -0,0 +1,78 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package co.elastic.clients.elasticsearch.json.jackson;
+
+import co.elastic.clients.json.JsonpMapper;
+import co.elastic.clients.json.JsonpUtils;
+import co.elastic.clients.json.jackson.JacksonJsonpMapper;
+import jakarta.json.JsonObject;
+import jakarta.json.JsonValue;
+import jakarta.json.stream.JsonParser;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.StringReader;
+import java.util.Map;
+
+public class JsonValueParserTest extends Assert {
+
+    public static class Data {
+        public Map<String, Object> data;
+    }
+
+    @Test
+    public void testFloatsShouldDeserializeAsFloats() throws Exception {
+        // When using Jackson to target a map of objects, values with a decimal separator
+        // should deserialize as a double even if they fit in an int or long.
+        // See https://github.com/elastic/elasticsearch-java/issues/156
+
+        String json = "{\"data\": {\"value\": 1.4778125E7, \"value2\": 1.4778125E7 }}";
+        JsonpMapper mapper = new JacksonJsonpMapper();
+
+        {
+            JsonParser parser = mapper.jsonProvider().createParser(new StringReader(json));
+            Data data = mapper.deserialize(parser, Data.class);
+
+            Double d = (Double)data.data.get("value");
+            assertEquals(1.4778125E7, d, 0.001);
+        }
+
+        {
+            // Test with buffering used in union resolution
+            JsonParser parser = mapper.jsonProvider().createParser(new StringReader(json));
+            parser.next();
+            JsonObject object = parser.getObject();
+
+            // Test equals/hashcode
+            JsonValue v = object.getJsonObject("data").get("value");
+            JsonValue v2 = object.getJsonObject("data").get("value2");
+
+            assertEquals(v.hashCode(), v2.hashCode());
+            assertEquals(v, v2);
+            
+            parser = JsonpUtils.objectParser(object, mapper);
+            Data data = mapper.deserialize(parser, Data.class);
+
+            Double d = (Double)data.data.get("value");
+            assertEquals(1.4778125E7, d, 0.001);
+        }
+
+    }
+}