FSharp.Data emits invalid JSON for NaN, Infinity and -Infinity

[dbarbashov]

FSharp.Data serializes NaN as just NaN, Infinity as just Infinity and -Infinity as -Infinity.
If I understand it correctly, there is no JSON representation for these values, so emitted JSON is not valid.
Repro script:

open FSharp.Data

let serializeDeserializeFloat floatValue = 
    let jsonValue = JsonValue.Array ([| JsonValue.Float floatValue |])
    
    let json = jsonValue.ToString(JsonSaveOptions.DisableFormatting)
    printfn "Serialized: %A" json
    
    let jsonValue = JsonValue.Parse json
    printfn "Deserialized: %A" jsonValue
    
serializeDeserializeFloat 42.0
// OK
serializeDeserializeFloat nan    
// Throws exception
// System.Exception: Invalid JSON starting at character 1, snippet = 
// ----
// [NaN]
// -----
// json = 
// ------
// [NaN]
// -------
serializeDeserializeFloat infinity
//System.Exception: Invalid JSON starting at character 1, snippet = 
//----
//[Infinity]
//-----
//json = 
//------
//[Infinity]
//-------
serializeDeserializeFloat -infinity
//System.Exception: Invalid JSON starting at character 2, snippet = 
//----
//[-Infinity]
//-----
//json = 
//------
//[-Infinity]
//-------

For example, Firefox console encodes these values like this:

>> JSON.stringify([NaN, Infinity, -Infinity])
<< "[null,null,null]"

[dbarbashov]

For example Newtonsoft.Json serializes these values as strings. NaN is "NaN", Infinity is "Infinity" and -Infinity is "-Infinity", so it is able to deserialize it back to float and JSON is valid.

open Newtonsoft.Json

let serializeDeserializeFloatNewtonsoft floatValue =
    let json = JsonConvert.SerializeObject([| floatValue |])
    printfn "Serialized %A" json
    let deserialized = JsonConvert.DeserializeObject<float[]>(json)
    printfn "Deserialized %A" deserialized
    
serializeDeserializeFloatNewtonsoft 20.0
serializeDeserializeFloatNewtonsoft nan    
serializeDeserializeFloatNewtonsoft infinity
serializeDeserializeFloatNewtonsoft -infinity

Output:

Serialized "[20.0]"
Deserialized [|20.0|]
Serialized "["NaN"]"
Deserialized [|nan|]
Serialized "["Infinity"]"
Deserialized [|infinity|]
Serialized "["-Infinity"]"
Deserialized [|-infinity|]