Default values for DateTime/Date/Guid result in non-compileable code

[WolfgangHG]

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Windows executable

Client library/SDK language

Csharp

Describe the bug

I have a REST service developed with Swashbuckle (sample project below). The OpenAPI file is thus generated by Swashbuckle.
In the service data model, I have fields that have DefaultValue attributes:

public class WeatherForecast
{
  [DefaultValue(typeof(DateTime), "1900-01-01 00:00:00")]
  public DateTime DateValue { get; set; }

  [DefaultValue(typeof(DateOnly), "1900-01-01")]
  public DateOnly DateOnlyValue { get; set; }

  [DefaultValue(typeof(Guid), "00000000-0000-0000-0000-000000000000")]
  public Guid GuidValue { get; set; }

  [DefaultValue(typeof(TimeOnly), "00:00:00")]
  public TimeOnly TimeValue { get; set; }

  [DefaultValue(15)]
  public int TemperatureC { get; set; }

  public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);

  [DefaultValue("Test")]
  public string Summary { get; set; }
}

This results in this OpenAPI description:

"schemas": {
  "WeatherForecast": {
    "type": "object",
    "properties": {
      "dateValue": {
        "type": "string",
        "format": "date-time",
        "default": "1900-01-01T00:00:00"
      },
      "dateOnlyValue": {
        "type": "string",
        "format": "date",
        "default": "1900-01-01"
      },
      "guidValue": {
        "type": "string",
        "format": "uuid",
        "default": "00000000-0000-0000-0000-000000000000"
      },
      "timeValue": {
        "type": "string",
        "format": "time",
        "default": "00:00:00"
      },
      "temperatureC": {
        "type": "integer",
        "format": "int32",
        "default": 15
      },
      "temperatureF": {
        "type": "integer",
        "format": "int32",
        "readOnly": true
      },
      "summary": {
        "type": "string",
        "default": "Test",
        "nullable": true
      }
    },
    "additionalProperties": false
  }
}

(format "time" is actually OpenAPI 3.1, while my sample is 3.0)

Kiota creates this class from this file:

  public Date? DateOnlyValue { get; set; }
  public DateTimeOffset? DateValue { get; set; }
  public Guid? GuidValue { get; set; }
  public Time? TimeValue { get; set; }
  public string? Summary { get; set; }
  public int? TemperatureC { get; set; }
  public int? TemperatureF { get; private set; }

  public WeatherForecast()
  {
      DateOnlyValue = "1900-01-01";
      DateValue = "1900-01-01T00:00:00";
      GuidValue = "00000000-0000-0000-0000-000000000000";
      Summary = "Test";
      TimeValue = "00:00:00";
  }

Most of the default value assignments don't compile:

And I wonder why the int field value is not initialized.

Expected behavior

The generated code should probably be:

public WeatherForecast()
{
    DateOnlyValue = new Date(DateTimeOffset.Parse("1900-01-01").Date);
    DateValue = DateTimeOffset.Parse("1900-01-01T00:00:00");
    GuidValue = Guid.Parse("00000000-0000-0000-0000-000000000000");
    TemperatureC = 15;
    Summary = "Test";
    TimeValue = new Time(DateTime.ParseExact("00:00:00", "HH:mm:ss", null));
}

How to reproduce

This is the REST service project: ASPNETCoreSwaggerDefaults.zip

Open it and start it by launching the profile "WebApiSwaggerVersion".

The client is found here: KiotaDefaults.zip

Copy the "swagger.json" file to the directory, then create the client by invoking "generate_kiota_client.bat".

Open API description file

swagger.json

Kiota Version

1.30.0

Latest Kiota version known to work for scenario above?(Not required)

No response

Known Workarounds

No response

Configuration

No response

Debug output

No response

Other information

No response

[WolfgangHG]

About my bonus question And I wonder why the int field value is not initialized.

I added further properties to my REST service project using data types like double or bool, and all those values are not set in the constructor.

This is the JSON schema:

"schemas": {
  "WeatherForecast": {
    "type": "object",
    "properties": {
      "dateValue": {
        "type": "string",
        "format": "date-time",
        "default": "1900-01-01T00:00:00"
      },
      "dateOnlyValue": {
        "type": "string",
        "format": "date",
        "default": "1900-01-01"
      },
      "guidValue": {
        "type": "string",
        "format": "uuid",
        "default": "00000000-0000-0000-0000-000000000000"
      },
      "temperatureC": {
        "type": "integer",
        "format": "int32",
        "default": 15
      },
      "temperatureF": {
        "type": "integer",
        "format": "int32",
        "readOnly": true
      },
      "summary": {
        "type": "string",
        "default": "Test",
        "nullable": true
      },
      "doubleValue": {
        "type": "number",
        "format": "double",
        "default": 25.5
      },
      "decimalValue": {
        "type": "number",
        "format": "double",
        "default": 25.5
      },
      "floatValue": {
        "type": "number",
        "format": "float",
        "default": 25.5
      },
      "boolValue": {
        "type": "boolean",
        "default": true
      }
    },
    "additionalProperties": false
  }
}

The generated class does not contain initializers for every value that is not placed in quotes.

The culprit seems to this line:

kiota/src/Kiota.Builder/KiotaBuilder.cs

Line 1211 in f8acfc2

stringDefaultJsonValue.TryGetValue<string>(out var stringDefaultValue) &&

==>stringDefaultJsonValue.TryGetValue<string> always returns false for values that are not in quotes.

[WolfgangHG]

I started working on this and think I fixed all those problems. But am not ready to send a pull request.

[gavinbarron]

Thank you for raising this and taking on a fix yourself.