Add a failing test for #4777

src/test/java/com/fasterxml/jackson/databind/tofix/JsonCreatorNoArgs4777Test.java

@@ -0,0 +1,64 @@
+package com.fasterxml.jackson.databind.tofix;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.deser.*;
+import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
+import com.fasterxml.jackson.databind.introspect.AnnotatedWithParams;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
+import com.fasterxml.jackson.databind.testutil.failure.JacksonTestFailureExpected;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+public class JsonCreatorNoArgs4777Test extends DatabindTestUtil
+{
+    static class Foo {
+        private Foo() { } 
+
+        @JsonCreator
+        static Foo create() {
+            return new Foo();
+        }
+    }
+
+    static class Instantiators implements ValueInstantiators {
+        @Override
+        public ValueInstantiator findValueInstantiator(
+                DeserializationConfig config,
+                BeanDescription beanDesc,
+                ValueInstantiator defaultInstantiator
+        ) {
+            if (beanDesc.getBeanClass() == Foo.class) {
+                AnnotatedWithParams dc = defaultInstantiator.getDefaultCreator();
+                if (!(dc instanceof AnnotatedMethod)
+                        || !dc.getName().equals("create")) {
+                    throw new IllegalArgumentException("Wrong DefaultCreator: should be static-method 'create()', is: "
+                            +dc);
+                }
+            }
+            return defaultInstantiator;
+        }
+    }
+
+    // For [databind#4777]
+    @SuppressWarnings("serial")
+    @Test
+    @JacksonTestFailureExpected
+    public void testCreatorDetection4777() throws Exception {
+        SimpleModule sm = new SimpleModule() {
+            @Override
+            public void setupModule(SetupContext context) {
+                super.setupModule(context);
+                context.addValueInstantiators(new Instantiators());
+            }
+        };
+        ObjectMapper mapper = JsonMapper.builder().addModule(sm).build();
+
+        Foo result = mapper.readValue("{}", Foo.class);
+        assertNotNull(result);
+    }
+}