Goals

I'd like to use make a realm model that has a RealmOptional property conform to Codable, and properly encode/decode properties in all scenarios.

Expected Results

I expected my object to be encodable and decodable when the key:value pairs are present, existing, or null, in a JSON structure.

Actual Results

Scenario 1: It works when the RealmOptional value is present.
Scenario 2: It works when the RealmOptional value is null.
Scenario 3: It does not work when the RealmOptional is not present.

Steps for others to Reproduce

<details><summary>Scenario 1 (it works)</summary>
<p>

Given the class:

class MyObject : Object, Decodable {
    dynamic var myOptional = RealmOptional<Double>()
}

And the following JSON:

{
    "myOptional" : 42.42
}

Decoding the JSON into MyObject.self works as expected.

</p>
</details>

<details><summary>Scenario 2 (it works)</summary>
<p>

Given the class:

class MyObject : Object, Decodable {
    dynamic var myOptional = RealmOptional<Double>()
}

And the following JSON:

{
    "myOptional" : null
}

Decoding the JSON into MyObject.self works as expected.

</p>
</details>

<details><summary>Scenario 3 (it doesn't work)</summary>
<p>

Given the class:

class MyObject : Object, Decodable {
    dynamic var myOptional = RealmOptional<Double>()
}

And the following JSON:

{
}

Decoding the JSON into MyObject.self fails, because the key cannot be found.

</p>
</details>

Code Sample

Code samples are located in the section below.

Version of Realm and Tooling

Realm framework version: 10.3.0

Realm Object Server version: idk

Xcode version: 12.2

iOS/OSX version: macOS 10.15.7

Dependency manager + version: SPM

Further Details

This issue was already raised over 3 years ago here: https://github.com/realm/realm-cocoa/issues/5012#issuecomment-326252157
I read that entire thread and the issue I'm referring to doesn't seem to have a closure. I checked this code posted here but that seemed to be an overkill to solve the problem. Maybe 3.5 years later there's a better solution.