default mapper cannot handle basic immutable class (#3898)

Author: pjfanning

src/test/java/com/fasterxml/jackson/databind/deser/creators/SingleImmutableFieldCreatorTest.java

@@ -0,0 +1,161 @@
+package com.fasterxml.jackson.databind.deser.creators;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.introspect.AnnotatedMember;
+import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;
+import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import org.junit.jupiter.api.Test;
+
+// [databind#3898]
+public class SingleImmutableFieldCreatorTest
+    extends DatabindTestUtil
+{
+    static class ImmutableId {
+        private final int id;
+
+        public ImmutableId(int id) { this.id = id; }
+
+        public int getId() {
+            return id;
+        }
+    }
+
+    static class ImmutableIdWithEmptyConstuctor {
+        private final int id;
+
+        public ImmutableIdWithEmptyConstuctor() { this(-1); }
+
+        public ImmutableIdWithEmptyConstuctor(int id) { this.id = id; }
+
+        public int getId() {
+            return id;
+        }
+    }
+
+    static class ImmutableIdWithJsonCreatorAnnotation {
+        private final int id;
+
+        @JsonCreator
+        public ImmutableIdWithJsonCreatorAnnotation(int id) { this.id = id; }
+
+        public int getId() {
+            return id;
+        }
+    }
+
+    static class ImmutableIdWithJsonPropertyFieldAnnotation {
+        @JsonProperty("id") private final int id;
+
+        public ImmutableIdWithJsonPropertyFieldAnnotation(int id) { this.id = id; }
+
+        public int getId() {
+            return id;
+        }
+    }
+
+    static class ImmutableIdWithJsonPropertyConstructorAnnotation {
+        private final int id;
+
+        public ImmutableIdWithJsonPropertyConstructorAnnotation(@JsonProperty("id") int id) { this.id = id; }
+
+        public int getId() {
+            return id;
+        }
+    }
+
+    static class MyParamIntrospector extends JacksonAnnotationIntrospector
+    {
+        private static final long serialVersionUID = 1L;
+
+        @Override
+        public String findImplicitPropertyName(AnnotatedMember param) {
+            return "id";
+        }
+    }
+
+    /*
+    /**********************************************************
+    /* Unit tests
+    /**********************************************************
+     */
+
+    @Test
+    public void testSetterlessProperty() throws Exception
+    {
+        ImmutableId input = new ImmutableId(13);
+        ObjectMapper m = new ObjectMapper();
+        m.setAnnotationIntrospector(new MyParamIntrospector());
+        String json = m.writerWithDefaultPrettyPrinter().writeValueAsString(input);
+
+        ImmutableId output = m.readValue(json, ImmutableId.class);
+        assertNotNull(output);
+
+        assertEquals(input.id, output.id);
+    }
+
+    // in the past, this was a workaround for the first test
+    @Test
+    public void testSetterlessPropertyWithEmptyConstructor() throws Exception
+    {
+        ImmutableIdWithEmptyConstuctor input = new ImmutableIdWithEmptyConstuctor(13);
+        ObjectMapper m = new ObjectMapper();
+        String json = m.writerWithDefaultPrettyPrinter().writeValueAsString(input);
+
+        ImmutableIdWithEmptyConstuctor output = m.readValue(json, ImmutableIdWithEmptyConstuctor.class);
+        assertNotNull(output);
+
+        assertEquals(input.id, output.id);
+    }
+
+    @Test
+    public void testSetterlessPropertyWithJsonCreator() throws Exception
+    {
+        ImmutableIdWithJsonCreatorAnnotation input = new ImmutableIdWithJsonCreatorAnnotation(13);
+        ObjectMapper m = new ObjectMapper();
+        m.setAnnotationIntrospector(new MyParamIntrospector());
+        String json = m.writerWithDefaultPrettyPrinter().writeValueAsString(input);
+
+        ImmutableIdWithJsonCreatorAnnotation output =
+                m.readValue(json, ImmutableIdWithJsonCreatorAnnotation.class);
+        assertNotNull(output);
+
+        assertEquals(input.id, output.id);
+    }
+
+    // in the past, this was a workaround for the first test
+    @Test
+    public void testSetterlessPropertyWithJsonPropertyField() throws Exception
+    {
+        ImmutableIdWithJsonPropertyConstructorAnnotation input = new ImmutableIdWithJsonPropertyConstructorAnnotation(13);
+        ObjectMapper m = new ObjectMapper();
+        String json = m.writerWithDefaultPrettyPrinter().writeValueAsString(input);
+
+        ImmutableIdWithJsonPropertyConstructorAnnotation output =
+                m.readValue(json, ImmutableIdWithJsonPropertyConstructorAnnotation.class);
+        assertNotNull(output);
+
+        assertEquals(input.id, output.id);
+    }
+
+    @Test
+    public void testSetterlessPropertyWithJsonPropertyConstructor() throws Exception
+    {
+        ImmutableIdWithJsonPropertyFieldAnnotation input = new ImmutableIdWithJsonPropertyFieldAnnotation(13);
+        ObjectMapper m = new ObjectMapper();
+        m.setAnnotationIntrospector(new MyParamIntrospector());
+        String json = m.writerWithDefaultPrettyPrinter().writeValueAsString(input);
+
+        ImmutableIdWithJsonPropertyFieldAnnotation output =
+                m.readValue(json, ImmutableIdWithJsonPropertyFieldAnnotation.class);
+        assertNotNull(output);
+
+        assertEquals(input.id, output.id);
+    }
+}