Clarifying about floating point types extra values

[orihomie]

There's another problem with float and double and its about this types scopes - they can be Infinity or NaN, but generated json schema points them as "number" only.
I think its could be a problem when casting json types onto C# Dto objects.

Originally posted by @orihomie in #1122 (comment)

I need to know if there's any solution for that problem without specifying type of such value like this:

"some_value": {
          "type": "number, string"
        }

This way there's no clarity if I got specific type strings like "NaN" / "Infinity" or any trash that shouldnt be there.
I've read old issues on OAS repo which were pointing this problem, but they, like this one, gave me no clarity on how I should I behave myself with such types.

[RicoSuter]

Cant a "number" be NaN or Infinity?

[orihomie]

It seems not cause I'm having a problem with that kind of json object:

{
	"id": 1,
	"date": "2019-12-16T20:31:48.68",
	"policyStartDate": "2020-01-21T00:00:00",
	"externalContractNumber": "",
	"userName": "skipped user name",
	"price": 0.0,
	"companyId": 2,
	"policyLink": "",
	"partnerCampaignMedium": "campaign",
	"policyBlankLink": null,
	"source": "skipped",
	"subId": "skipped",
	"registrationRoute": "route",
	"subAgentRoute": "skipped",
	"isAccepted": true,
	"withProlongation": true,
	"profit": 0.0,
	"profitPercent": "NaN",
	"hash": "skippedipped",
}

Look at this property:

"profitPercent": "NaN",

This is object's (property) C# code:

public double ProfitPercent { get; set; }

And this is error I'm getting when trying to validate it:

Shouldly.ShouldAssertException : validateResult.Count
    should be
0
    but was
1

Additional Info:
    ArrayItemNotValid: #/result[3]
{
  NumberExpected: #/result[3].profitPercent
}

This is the json schema of this object:

 "profitPercent": {
          "type": "number"
        },

This is how I generate schema's:

var schemaString = NJsonSchema.JsonSchema.FromSampleJson(result).ToJson();

And this is how I validate them:

var validateResult = new NJsonSchema.Validation.JsonSchemaValidator().Validate(result, schema);
validateResult.Count.ShouldBe(0, string.Join('\n', validateResult));

By the way - it seems neither NSwag or OAS spec supports nullable C# values. I mean I expect that value's schema to be like this:

 "someValue": {
          "type": "number, null"
        },

[RicoSuter]

With JSON Schema the "type" can also be an array, e.g. "type": ["number", "null"] but this is not allowed in Swagger 2.0 or OpenAPI 3.0.

In Swagger 2.0 there is no way to specify nullability - there is only required (which is often misused to also specify nullability).

In OpenAPI 3.0 a new property "nullable" on a property has been introduced:

"myproperty": {
   "type": "string",
   "nullable": true
}

[orihomie]

Ok, and what about "NaN" or "Inifinity" values? I'm not even mentioning C# methods checking if its positive or negative infinity

[RicoSuter]

Any idea what the correct way is to serialize NaN and Infinity with JSON? Maybe using "NaN" or "Inifinity" is correct but Newtonsoft.Json cannot handle it (with default settings)?

[orihomie]

How we could make possible to declare custom type with some mixed allowable values, like "number" type range of values along with "NaN" and "pInfinity" / "nInfinity" ?
This is idea I'm thinking of (sry, lacking a bit of exp in json stuff).