Backport #2236 fix, accidentally started from master

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -33,6 +33,8 @@ Project: jackson-databind
  (reported by RightHandedMonkey@github)
 #2230: `WRITE_BIGDECIMAL_AS_PLAIN` is ignored if `@JsonFormat` is used
  (reported by Pavel C)
+#2236: Type id not provided on `Double.NaN`, `Infinity` with `@JsonTypeInfo`
+ (reported by C-B-B@github)
 #2241: Add `JsonPropertyNamingStrategy.LOWER_DOT_CASE` for dot-delimited names
  (contributed by zenglian@github.com)
 

src/main/java/com/fasterxml/jackson/databind/ser/std/NumberSerializers.java

@@ -8,7 +8,7 @@
 import com.fasterxml.jackson.annotation.JsonFormat;
 
 import com.fasterxml.jackson.core.*;
-
+import com.fasterxml.jackson.core.type.WritableTypeId;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
 import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
@@ -231,11 +231,26 @@ public void serialize(Object value, JsonGenerator gen,
 
         // IMPORTANT: copied from `NonTypedScalarSerializerBase`
         @Override
-        public void serializeWithType(Object value, JsonGenerator gen,
+        public void serializeWithType(Object value, JsonGenerator g,
                 SerializerProvider provider, TypeSerializer typeSer)
                 throws IOException {
-            // no type info, just regular serialization
-            serialize(value, gen, provider);
+            // 08-Feb-2018, tatu: Except that as per [databind#2236], NaN values need
+            //    special handling
+            Double d = (Double) value;
+            if (notFinite(d)) {
+                WritableTypeId typeIdDef = typeSer.writeTypePrefix(g,
+                        // whether to indicate it's number or string is arbitrary; important it is scalar
+                        typeSer.typeId(value, JsonToken.VALUE_NUMBER_FLOAT));
+                g.writeNumber(d);
+                typeSer.writeTypeSuffix(g, typeIdDef);
+            } else {
+                g.writeNumber(d);
+            }
+        }
+
+        public static boolean notFinite(double value) {
+            // `jackson-core` has helper method in 3 but not yet
+            return Double.isNaN(value) || Double.isInfinite(value);
         }
     }
 }

src/test/java/com/fasterxml/jackson/databind/jsontype/deftyping/TestDefaultForScalars.java

@@ -25,12 +25,29 @@ static class Data {
         public long key;
     }
 
+    // Basic `ObjectWrapper` from base uses delegating ctor, won't work well; should
+    // figure out why, but until then we'll use separate impl
+    protected static class ObjectWrapperForPoly {
+        Object object;
+
+        protected ObjectWrapperForPoly() { }
+        public ObjectWrapperForPoly(final Object o) {
+            object = o;
+        }
+        public Object getObject() { return object; }
+    }
+
     /*
     /**********************************************************
     /* Test methods
     /**********************************************************
      */
-    
+
+    private final ObjectMapper DEFAULT_TYPING_MAPPER = newObjectMapper();
+    {
+        DEFAULT_TYPING_MAPPER.enableDefaultTyping();
+    }
+
     /**
      * Unit test to verify that limited number of core types do NOT include
      * type information, even if declared as Object. This is only done for types
@@ -39,45 +56,36 @@ static class Data {
      */
     public void testNumericScalars() throws Exception
     {
-        ObjectMapper m = new ObjectMapper();
-        m.enableDefaultTyping();
-
         // no typing for Integer, Double, yes for others
-        assertEquals("[123]", m.writeValueAsString(new Object[] { Integer.valueOf(123) }));
-        assertEquals("[[\"java.lang.Long\",37]]", m.writeValueAsString(new Object[] { Long.valueOf(37) }));
-        assertEquals("[0.25]", m.writeValueAsString(new Object[] { Double.valueOf(0.25) }));
-        assertEquals("[[\"java.lang.Float\",0.5]]", m.writeValueAsString(new Object[] { Float.valueOf(0.5f) }));
+        assertEquals("[123]", DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { Integer.valueOf(123) }));
+        assertEquals("[[\"java.lang.Long\",37]]", DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { Long.valueOf(37) }));
+        assertEquals("[0.25]", DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { Double.valueOf(0.25) }));
+        assertEquals("[[\"java.lang.Float\",0.5]]", DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { Float.valueOf(0.5f) }));
     }
 
     public void testDateScalars() throws Exception
     {
-        ObjectMapper m = new ObjectMapper();
-        m.enableDefaultTyping();
-
         long ts = 12345678L;
         assertEquals("[[\"java.util.Date\","+ts+"]]",
-                m.writeValueAsString(new Object[] { new Date(ts) }));
+                DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { new Date(ts) }));
 
         // Calendar is trickier... hmmh. Need to ensure round-tripping
         Calendar c = Calendar.getInstance();
         c.setTimeInMillis(ts);
-        String json = m.writeValueAsString(new Object[] { c });
+        String json = DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { c });
         assertEquals("[[\""+c.getClass().getName()+"\","+ts+"]]", json);
         // and let's make sure it also comes back same way:
-        Object[] result = m.readValue(json, Object[].class);
+        Object[] result = DEFAULT_TYPING_MAPPER.readValue(json, Object[].class);
         assertEquals(1, result.length);
         assertTrue(result[0] instanceof Calendar);
         assertEquals(ts, ((Calendar) result[0]).getTimeInMillis());
     }
 
     public void testMiscScalars() throws Exception
     {
-        ObjectMapper m = new ObjectMapper();
-        m.enableDefaultTyping();
-
         // no typing for Strings, booleans
-        assertEquals("[\"abc\"]", m.writeValueAsString(new Object[] { "abc" }));
-        assertEquals("[true,null,false]", m.writeValueAsString(new Boolean[] { true, null, false }));
+        assertEquals("[\"abc\"]", DEFAULT_TYPING_MAPPER.writeValueAsString(new Object[] { "abc" }));
+        assertEquals("[true,null,false]", DEFAULT_TYPING_MAPPER.writeValueAsString(new Boolean[] { true, null, false }));
     }
 
     /**
@@ -101,11 +109,9 @@ public void testScalarArrays() throws Exception
 
     public void test417() throws Exception
     {
-        ObjectMapper m = new ObjectMapper();
-        m.enableDefaultTyping();
         Jackson417Bean input = new Jackson417Bean();
-        String json = m.writeValueAsString(input);
-        Jackson417Bean result = m.readValue(json, Jackson417Bean.class);
+        String json = DEFAULT_TYPING_MAPPER.writeValueAsString(input);
+        Jackson417Bean result = DEFAULT_TYPING_MAPPER.readValue(json, Jackson417Bean.class);
         assertEquals(input.foo, result.foo);
         assertEquals(input.bar, result.bar);
     }
@@ -136,4 +142,15 @@ public void testDefaultTypingWithLong() throws Exception
         assertNotNull(result);
         assertEquals(2, result.size());
     }
+
+    // [databind#2236]: do need type info for NaN
+    public void testDefaultTypingWithNaN() throws Exception
+    {
+        final ObjectWrapperForPoly INPUT = new ObjectWrapperForPoly(Double.POSITIVE_INFINITY);
+        final String json = DEFAULT_TYPING_MAPPER.writeValueAsString(INPUT);
+        final ObjectWrapperForPoly result = DEFAULT_TYPING_MAPPER.readValue(json, ObjectWrapperForPoly.class);
+        assertEquals(Double.class, result.getObject().getClass());
+        assertEquals(INPUT.getObject().toString(), result.getObject().toString());
+        assertTrue(((Double) result.getObject()).isInfinite());
+    }
 }