Misleading validation error for `anyOf` property when required value is invalid

[pshevche]

Summary

Hey everyone, we try to upgrade from version 1.0.69 to 1.0.77 and observe that the validation errors for a certain scenario changed starting with 1.0.74. The error is a bit misleading and I'd like to get your thoughts on whether the previous behavior can be restored or if it will stay this way. The detailed test case is attached.

To sum it up, we have an object that can either be null or have a required enum property. If the property supplied is invalid, then:

• before 1.0.74, we would only get a validation error stating that $.optionalObject.value: does not have a value in the enumeration
• after 1.0.74, we would also get a message that $.optionalObject: object found, null expected which is not true, since optionalObject can be an object, it just happens that this object is not valid.

I'd expect to only get a message about the value in this case.

Reproducer

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.networknt.schema.JsonSchemaFactory;
import com.networknt.schema.SpecVersion;
import com.networknt.schema.ValidationMessage;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

class ReproducerTest {
    private static final String SCHEMA = """
        {
           "$schema": "http://json-schema.org/draft-07/schema#",
           "properties": {
               "optionalObject": {
                   "anyOf": [
                       {
                           "type": "null"
                       },
                       {
                           "type": "object",
                           "properties": {
                               "value": {
                                   "enum": [
                                       "one",
                                       "two"
                                   ]
                               }
                           },
                           "required": [
                               "value"
                           ]
                       }
                   ]
               }
           }
        }""";

    private static final String INVALID_VALUE = """
        {
            "optionalObject": {
                "value": "invalid"
            }
        }""";

    @Test
    void testCorrectErrorForInvalidValue() throws JsonProcessingException {
        var mapper = new ObjectMapper();
        var schema = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V7).getSchema(SCHEMA);

        var errors = schema.validate(mapper.readTree(INVALID_VALUE));
        var errorMessages = errors.stream().map(ValidationMessage::getMessage).toList();

        assertTrue(errorMessages.contains("$.optionalObject.value: does not have a value in the enumeration [one, two]"));
        assertFalse(errorMessages.contains("$.optionalObject: object found, null expected"));
    }
}

[stevehu]

I have checked the release notes for 1.0.74, and this PR is the only possible culprit. It only added the JSON path to the error message as I see in the code. Could you please confirm? Thanks.

#626

[pshevche]

@stevehu , that PR was indeed the problem. TL;DR we relied on the schema path to differentiate between regular type validators and those belonging to the anyOf operator. I tried to solve the issue in the linked PR. Looking forward to your feedback