JsonObjectValidator.cs

using System.Collections.Generic;
using System.Linq;
using Microsoft.OpenApi.Models;
using Newtonsoft.Json.Linq;

namespace Swashbuckle.AspNetCore.ApiTesting
{
    public class JsonObjectValidator(IJsonValidator jsonValidator) : IJsonValidator
    {
        private readonly IJsonValidator _jsonValidator = jsonValidator;

        public bool CanValidate(OpenApiSchema schema) => schema.Type == JsonSchemaTypes.Object;

        public bool Validate(
            OpenApiSchema schema,
            OpenApiDocument openApiDocument,
            JToken instance,
            out IEnumerable<string> errorMessages)
        {
            if (instance.Type != JTokenType.Object)
            {
                errorMessages = [$"Path: {instance.Path}. Instance is not of type 'object'"];
                return false;
            }

            var jObject = (JObject)instance;
            var properties = jObject.Properties();
            var errorMessagesList = new List<string>();

            // maxProperties
            if (schema.MaxProperties.HasValue && properties.Count() > schema.MaxProperties.Value)
            {
                errorMessagesList.Add($"Path: {instance.Path}. Number of properties is greater than maxProperties");
            }

            // minProperties
            if (schema.MinProperties.HasValue && properties.Count() < schema.MinProperties.Value)
            {
                errorMessagesList.Add($"Path: {instance.Path}. Number of properties is less than minProperties");
            }

            // required
            if (schema.Required != null && schema.Required.Except(properties.Select(p => p.Name)).Any())
            {
                errorMessagesList.Add($"Path: {instance.Path}. Required property(s) not present");
            }

            foreach (var property in properties)
            {
                // properties
                IEnumerable<string> propertyErrorMessages;

                if (schema.Properties != null && schema.Properties.TryGetValue(property.Name, out OpenApiSchema propertySchema))
                {
                    if (!_jsonValidator.Validate(propertySchema, openApiDocument, property.Value, out propertyErrorMessages))
                    {
                        errorMessagesList.AddRange(propertyErrorMessages);
                    }

                    continue;
                }

                if (!schema.AdditionalPropertiesAllowed)
                {
                    errorMessagesList.Add($"Path: {instance.Path}. Additional properties not allowed");
                }

                // additionalProperties
                if (schema.AdditionalProperties != null &&
                    !_jsonValidator.Validate(schema.AdditionalProperties, openApiDocument, property.Value, out propertyErrorMessages))
                {
                    errorMessagesList.AddRange(propertyErrorMessages);
                }
            }

            errorMessages = errorMessagesList;
            return !errorMessages.Any();
        }
    }
}