fix: Add custom attribute for OptionValue and OptionLabel and allow empty string

backend/src/Designer/Exceptions/Options/InvalidOptionsFormatException.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Altinn.Studio.Designer.Exceptions.Options;
+
+/// <summary>
+/// Indicates that an error occurred during json serialization of options.
+/// </summary>
+[Serializable]
+public class InvalidOptionsFormatException : Exception
+{
+    /// <inheritdoc/>
+    public InvalidOptionsFormatException()
+    {
+    }
+
+    /// <inheritdoc/>
+    public InvalidOptionsFormatException(string message) : base(message)
+    {
+    }
+
+    /// <inheritdoc/>
+    public InvalidOptionsFormatException(string message, Exception innerException) : base(message, innerException)
+    {
+    }
+}

backend/src/Designer/Filters/Options/OptionsErrorCodes.cs

@@ -0,0 +1,6 @@
+namespace Altinn.Studio.Designer.Filters.Options;
+
+public class OptionsErrorCodes
+{
+    public const string InvalidOptionsFormat = nameof(InvalidOptionsFormat);
+}

backend/src/Designer/Filters/Options/OptionsExceptionFilterAttribute.cs

@@ -0,0 +1,26 @@
+using System.Net;
+using Altinn.Studio.Designer.Exceptions.Options;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Controllers;
+using Microsoft.AspNetCore.Mvc.Filters;
+
+namespace Altinn.Studio.Designer.Filters.Options;
+
+public class OptionsExceptionFilterAttribute : ExceptionFilterAttribute
+{
+    public override void OnException(ExceptionContext context)
+    {
+        base.OnException(context);
+
+        if (context.ActionDescriptor is not ControllerActionDescriptor)
+        {
+            return;
+        }
+
+        if (context.Exception is InvalidOptionsFormatException)
+        {
+            context.Result = new ObjectResult(ProblemDetailsUtils.GenerateProblemDetails(context.Exception, OptionsErrorCodes.InvalidOptionsFormat, HttpStatusCode.BadRequest)) { StatusCode = (int)HttpStatusCode.BadRequest };
+        }
+    }
+
+}

backend/src/Designer/Filters/ProblemDetailsExtensionsCodes.cs

@@ -3,5 +3,5 @@ namespace Altinn.Studio.Designer.Filters;
 public static class ProblemDetailsExtensionsCodes
 {
     public const string ErrorCode = "errorCode";
-
+    public const string Detail = "detail";
 }

backend/src/Designer/Helpers/JsonConverterHelpers/NotNullableAttribute.cs

@@ -0,0 +1,15 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Altinn.Studio.Designer.Helpers.JsonConverterHelpers;
+
+public class NotNullableAttribute : ValidationAttribute
+{
+    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+    {
+        if (value == null)
+        {
+            return new ValidationResult("The field is required.");
+        }
+        return ValidationResult.Success;
+    }
+}

backend/src/Designer/Helpers/JsonConverterHelpers/OptionConverterHelper.cs

@@ -1,10 +1,11 @@
 using System;
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using Altinn.Studio.Designer.Exceptions.Options;
 
 namespace Altinn.Studio.Designer.Helpers.JsonConverterHelpers;
 
-public class OptionConverter : JsonConverter<object>
+public class OptionValueConverter : JsonConverter<object>
 {
     public override object Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
     {
@@ -14,7 +15,7 @@ public override object Read(ref Utf8JsonReader reader, Type typeToConvert, JsonS
             JsonTokenType.Number when reader.TryGetDouble(out double d) => d,
             JsonTokenType.True => true,
             JsonTokenType.False => false,
-            _ => throw new JsonException($"Unsupported JSON token for Option.Value: {reader.TokenType}")
+            _ => throw new InvalidOptionsFormatException($"Unsupported JSON token for Value field, {typeToConvert}: {reader.TokenType}.")
         };
     }
 
@@ -32,7 +33,7 @@ public override void Write(Utf8JsonWriter writer, object value, JsonSerializerOp
                 writer.WriteBooleanValue(b);
                 break;
             default:
-                throw new JsonException("Unsupported type for Option.Value.");
+                throw new InvalidOptionsFormatException($"{value} is an unsupported type for Value field.");
         }
     }
 }

backend/src/Designer/Infrastructure/MvcConfiguration.cs

@@ -2,6 +2,7 @@
 using Altinn.Studio.Designer.Filters.DataModeling;
 using Altinn.Studio.Designer.Filters.Git;
 using Altinn.Studio.Designer.Filters.IO;
+using Altinn.Studio.Designer.Filters.Options;
 using Altinn.Studio.Designer.ModelBinding;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;
@@ -26,6 +27,7 @@ public static IServiceCollection ConfigureMvc(this IServiceCollection services)
                     options.Filters.Add(typeof(DataModelingExceptionFilterAttribute));
                     options.Filters.Add(typeof(GitExceptionFilterAttribute));
                     options.Filters.Add(typeof(IoExceptionFilterAttribute));
+                    options.Filters.Add(typeof(OptionsExceptionFilterAttribute));
                 })
                 .AddNewtonsoftJson(options => options.SerializerSettings.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter()));
 

backend/src/Designer/Models/Option.cs

@@ -1,4 +1,3 @@
-using System.ComponentModel.DataAnnotations;
 using System.Text.Json.Serialization;
 using Altinn.Studio.Designer.Helpers.JsonConverterHelpers;
 
@@ -12,17 +11,17 @@ public class Option
     /// <summary>
     /// Value that connects the option to the data model.
     /// </summary>
-    [Required]
+    [NotNullable]
     [JsonPropertyName("value")]
-    [JsonConverter(typeof(OptionConverter))]
-    public object Value { get; set; }
+    [JsonConverter(typeof(OptionValueConverter))]
+    public required object Value { get; set; }
 
     /// <summary>
     /// Label to present to the user.
     /// </summary>
-    [Required]
+    [NotNullable]
     [JsonPropertyName("label")]
-    public string Label { get; set; }
+    public required string Label { get; set; }
 
     /// <summary>
     /// Description, typically displayed below the label.

backend/src/Designer/Services/Implementation/OptionsService.cs

@@ -1,8 +1,9 @@
 using System.Collections.Generic;
-using System.Linq;
+using System.ComponentModel.DataAnnotations;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
+using Altinn.Studio.Designer.Exceptions.Options;
 using Altinn.Studio.Designer.Models;
 using Altinn.Studio.Designer.Services.Interfaces;
 using LibGit2Sharp;
@@ -50,9 +51,26 @@ public async Task<List<Option>> GetOptionsList(string org, string repo, string d
 
         string optionsListString = await altinnAppGitRepository.GetOptionsList(optionsListId, cancellationToken);
         var optionsList = JsonSerializer.Deserialize<List<Option>>(optionsListString);
+
+        try
+        {
+            optionsList.ForEach(ValidateOption);
+        }
+        catch (ValidationException)
+        {
+            throw new InvalidOptionsFormatException($"One or more of the options have an invalid format in file: {optionsListId}.");
+        }
+
+
         return optionsList;
     }
 
+    private void ValidateOption(Option option)
+    {
+        var validationContext = new ValidationContext(option);
+        Validator.ValidateObject(option, validationContext, validateAllProperties: true);
+    }
+
     /// <inheritdoc />
     public async Task<List<Option>> CreateOrOverwriteOptionsList(string org, string repo, string developer, string optionsListId, List<Option> payload, CancellationToken cancellationToken = default)
     {
@@ -73,28 +91,12 @@ public async Task<List<Option>> UploadNewOption(string org, string repo, string
         List<Option> deserializedOptions = JsonSerializer.Deserialize<List<Option>>(payload.OpenReadStream(),
             new JsonSerializerOptions { WriteIndented = true, AllowTrailingCommas = true });
 
-        IEnumerable<Option> result = deserializedOptions.Where(option => IsNullOrEmptyOptionValue(option) || string.IsNullOrEmpty(option.Label));
-        if (result.Any())
-        {
-            throw new JsonException("Uploaded file is missing one of the following attributes for an option: value or label.");
-        }
-
         var altinnAppGitRepository = _altinnGitRepositoryFactory.GetAltinnAppGitRepository(org, repo, developer);
         await altinnAppGitRepository.CreateOrOverwriteOptionsList(optionsListId, deserializedOptions, cancellationToken);
 
         return deserializedOptions;
     }
 
-    bool IsNullOrEmptyOptionValue(object value)
-    {
-        if (value == null)
-        {
-            return true;
-        }
-
-        return value is string stringOption && string.IsNullOrEmpty(stringOption);
-    }
-
     /// <inheritdoc />
     public void DeleteOptionsList(string org, string repo, string developer, string optionsListId)
     {

backend/tests/Designer.Tests/Controllers/AppDevelopmentController/GetOptionListIdsTests.cs

@@ -29,6 +29,7 @@ public async Task GetOptionsListIds_ShouldReturnOk(string org, string app, strin
             {
                 { "other-options" },
                 { "test-options" },
+                { "options-with-null-fields" },
             };
 
             string url = $"{VersionPrefix(org, targetRepository)}/option-list-ids";
@@ -39,7 +40,7 @@ public async Task GetOptionsListIds_ShouldReturnOk(string org, string app, strin
 
             string responseContent = await response.Content.ReadAsStringAsync();
             List<string> responseList = JsonSerializer.Deserialize<List<string>>(responseContent);
-            responseList.Count.Should().Be(2);
+            responseList.Count.Should().Be(3);
             foreach (string id in expectedOptionsListIds)
             {
                 responseList.Should().Contain(id);

backend/tests/Designer.Tests/Controllers/OptionsController/GetOptionsTests.cs

@@ -1,11 +1,13 @@
 using System.Collections.Generic;
-using System.Linq;
 using System.Net.Http;
 using System.Text.Json;
 using System.Threading.Tasks;
+using Altinn.Studio.Designer.Filters;
 using Altinn.Studio.Designer.Models;
 using Designer.Tests.Controllers.ApiTests;
+using FluentAssertions;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Testing;
 using Xunit;
 
@@ -96,4 +98,26 @@ public async Task GetSingleOptionsList_Returns404NotFound_WhenOptionsListDoesNot
         // Assert
         Assert.Equal(StatusCodes.Status404NotFound, (int)response.StatusCode);
     }
+
+    [Fact]
+    public async Task GetSingleOptionsList_Returns400BadRequest_WhenOptionsListIsInvalid()
+    {
+        // Arrange
+        const string repo = "app-with-options";
+        const string optionsListId = "options-with-null-fields";
+
+        string apiUrl = $"/designer/api/ttd/{repo}/options/{optionsListId}";
+        using HttpRequestMessage httpRequestMessage = new(HttpMethod.Get, apiUrl);
+
+        // Act
+        using HttpResponseMessage response = await HttpClient.SendAsync(httpRequestMessage);
+
+        // Assert
+        Assert.Equal(StatusCodes.Status400BadRequest, (int)response.StatusCode);
+
+        var problemDetails = JsonSerializer.Deserialize<ProblemDetails>(await response.Content.ReadAsStringAsync());
+        problemDetails.Should().NotBeNull();
+        JsonElement errorCode = (JsonElement)problemDetails.Extensions[ProblemDetailsExtensionsCodes.ErrorCode];
+        errorCode.ToString().Should().Be("InvalidOptionsFormat");
+    }
 }