Replace Newtonsoft.Json with System.Text.Json

[webwarrior-ws]

Replace Newtonsoft.Json with System.Text.Json so that we don't
have different libraries for JSON, because System.Text.Json
will be used by GRPC services.

Also use FSharp.SystemTextJson library so that all F# types,
including discriminated unions, can be serialized using
System.Text.Json.

[knocte]

@webwarrior-ws I didn't tell you to add FSharp.SystemTextJson, I told you to play with it and, if it works, add a TODO. Because I didn't want this dependency in this PR! Please put the converters back. And save these commits for a future PR.

[webwarrior-ws]

@webwarrior-ws I didn't tell you to add FSharp.SystemTextJson, I told you to play with it and, if it works, add a TODO. Because I didn't want this dependency in this PR! Please put the converters back. And save these commits for a future PR.

But converters didn't work. Or they were not enough. With FSharp.SystemTextJson, it works.

[knocte]

Isn't there a way of doing what you did in 5845515 but with System.Text.Json? I'm sure there is.

[webwarrior-ws]

Isn't there a way of doing what you did in 5845515 but with System.Text.Json? I'm sure there is.

But it was another bug. Failed condition was

FX/src/FX.Tests/RedisIntegrationTests.cs

Line 62 in 33ce6fa

Assert.That(value.HasValue, Is.EqualTo(true),

, but with decimal it is

FX/src/FX.Tests/RedisIntegrationTests.cs

Line 80 in 33ce6fa

Assert.That(order.ToString(),

[knocte]

Then in the same way you have splitted the decimal thing in 2, you have to separate the 1st commit in 2 where you add FSharpSystemJson in the 2nd commit and explain the fix.

[knocte]

But it was another bug. Failed condition was

FX/src/FX.Tests/RedisIntegrationTests.cs

Line 62 in 33ce6fa

Assert.That(value.HasValue, Is.EqualTo(true),

, but with decimal it is

FX/src/FX.Tests/RedisIntegrationTests.cs

Line 80 in 33ce6fa

Assert.That(order.ToString(),

You didn't explain the above in the 2nd commit msg.

[webwarrior-ws]

@knocte expanded message of second commit with explanation of what didn't work with just System.Text.Json

[knocte]

indicating that something is wrong with serizlization.

Something is wrong with serialization? I thought you had looked into what is wrong? Then explain it. Also typo 'serizlization' -> 'serialization'.

[knocte]

@webwarrior-ws great comment and great investigation, however, let's improve some things here:

1. Instead of writing a converter, it's better to just make the tests be more liberal, and accept that x.0 is the same as x; let's write our own Assert.DecimalEquals function for example. We switched to FSharp.SystemTextJson to avoid converters!
2. This comment should go in the commit message as well

[webwarrior-ws]

If test was comparing decimals, there would be no problem. But test compares strings (serialized json).

[knocte]

the tests are just making sure that Redis works; you could deserialize the JSON and make sure the ending object is the same (since they are records, an Equals invokation should work)

[webwarrior-ws]

indicating that something is wrong with serizlization.

Something is wrong with serialization? I thought you had looked into what is wrong? Then explain it. Also typo 'serizlization' -> 'serialization'.

I haven't found what exactly is wrong.

[webwarrior-ws]

Fixed typo in second commit's message.

[knocte]

I haven't found what exactly is wrong.

Let's investigate then, I want clear reasons for migrating to FSharp.SystemTextJson.

[webwarrior-ws]

I haven't found what exactly is wrong.

Let's investigate then, I want clear reasons for migrating to FSharp.SystemTextJson.

It turns out that tests were using Newtonsoft.Json. I don't know how that project compiled without references to Newtonsoft.Json in any project files or Directory.Packages.props.

[webwarrior-ws]

With that fixed, we don't need custom converter for decimal.