How to set up open api spec so that lists do not have nullable elements?

[marcinjahn]

Here's a schema of the response of my API endpoint:

      "MyResponseDto": {
        "type": "object",
        "properties": {
          "codes": {
            "type": "array",
            "items": {
              "type": "integer",
              "format": "int32"
            }
          }
        },
        "additionalProperties": false
      },

The codes field, as generated by Kiota, looks as follows:

        /// <summary>The codes property</summary>
#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
#nullable enable
        public List<int?>? Codes { get; set; }
#nullable restore
#else
        public List<int?> Codes { get; set; }
#endif

There are two issues here:

1. The list contains nullable integers - how do I make it a list of non-nullable ints?
2. The field itself is nullable - how do I make it a non-nullable list?

[baywet]

Hi @marcinjahn
Thank you for using kiota and for reaching out.

1. This is by design, supporting non-nullable primitives would have impacts on the serialization/deserialization interfaces. There's an ongoing discussion about the support of non-nullable. [Multiple languages] properties are generated as nullable/optional, despite required/nullable usage in OAS schema #3911
2. Likewise, this is by design, assuming selection query parameters, or depending on the data, the response could NOT contains any list of codes. This is why the property is generated as nullable.

In C#, you can use OfType() to filter out/cast the values while conserving order. You can also use a combination of null propagation, null coalesce and collection initialization [] to manipulate the data.

All together var results = myObject?.Codes?.OfType<int>() ?? []

Let us know if you have any additional comments or questions.