add tests for polymorphic subtype deserialization (#5017)

Author: pjfanning

src/test/java/com/fasterxml/jackson/databind/jsontype/PolymorphicDeserSubtypeCheck5016Test.java

@@ -0,0 +1,98 @@
+package com.fasterxml.jackson.databind.jsontype;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
+import com.fasterxml.jackson.databind.exc.InvalidTypeIdException;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+// https://github.com/FasterXML/jackson-databind/issues/5016
+public class PolymorphicDeserSubtypeCheck5016Test extends DatabindTestUtil
+{
+    static abstract class Animal {
+        public String name = "animal";
+    }
+
+    static abstract class Plant {
+        public String name = "plant";
+    }
+
+    static class Cat extends Animal {
+        public String name = "cat";
+    }
+
+    static class Dog extends Animal implements Runnable {
+        public String name = "dog";
+
+        @Override
+        public void run() {
+            System.out.println("Dog is running");
+        }
+    }
+
+    static class Tree extends Plant {
+        public String name = "tree";
+    }
+
+    static class AnimalInfo {
+        @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS,
+                include = JsonTypeInfo.As.PROPERTY,
+                property = "@class")
+        public Animal thisType;
+    }
+
+    static class PlantInfo {
+        @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS,
+                include = JsonTypeInfo.As.PROPERTY,
+                property = "@class")
+        public Plant thisType;
+    }
+
+    static class RunnableInfo {
+        @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS,
+                include = JsonTypeInfo.As.PROPERTY,
+                property = "@class")
+        public Runnable thisType;
+    }
+
+    @Test
+    public void testWrongSubtype() throws Exception {
+        ObjectMapper mapper = newJsonMapper();
+        PlantInfo plantInfo = new PlantInfo();
+        plantInfo.thisType = new Tree();
+        String serialized = mapper.writeValueAsString(plantInfo);
+        PlantInfo newInfo0 = mapper.readValue(serialized, PlantInfo.class);
+        assertEquals(plantInfo.thisType.name, newInfo0.thisType.name);
+        // AnimalInfo has same JSON structure but incompatible type for `thisType`
+        InvalidTypeIdException e = assertThrows(InvalidTypeIdException.class, () ->
+                mapper.readValue(serialized, AnimalInfo.class));
+        verifyException(e, "Could not resolve type id ");
+        verifyException(e, "Not a subtype");
+    }
+
+    // java.lang.Runnable not acceptable as safe base type
+    @Test
+    public void testBlockingOfRunnable() throws Exception {
+        ObjectMapper mapper = JsonMapper.builder()
+                .enable(MapperFeature.BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)
+                .build();
+        AnimalInfo animalInfo = new AnimalInfo();
+        animalInfo.thisType = new Dog();
+        String serialized = mapper.writeValueAsString(animalInfo);
+        AnimalInfo newInfo0 = mapper.readValue(serialized, AnimalInfo.class);
+        assertEquals(animalInfo.thisType.name, newInfo0.thisType.name);
+        try {
+            mapper.readValue(serialized, RunnableInfo.class);
+        } catch (InvalidDefinitionException e) {
+            verifyException(e, "PolymorphicTypeValidator");
+            verifyException(e, "denied resolution of all subtypes of base type `java.lang.Runnable`");
+        }
+    }
+}