Add DocMigrator to handle deserialization and migrations

[reavessm]

This is currently a WIP as I'm still not exactly sure how to instantiate the migrator and include the prebuilt deserializer. This is a little out of my dotnet depth so it may take me a bit to figure out, but I'm going to go ahead push here to get some more eyes on it

[reavessm]

Also, this required some version bumps to get working with docmigrator, so I ran dotnet outdated . -u, but because it's currently not building, I'm not sure if that was a little heavy handed. Some of the deps crossed major version boundaries so we may need to roll those back

[Timmoth]

I would say create a new Deserializer class called RackPeekConfigMigrationDeserializer which implements YamlMigrationDeserializer<YamlRoot>like you see in the Readme of docmigrator https://github.com/Timmoth/DocMigrator

Then register it during startup in DI (it's fine to be a singleton and include the yaml (de)serializer builder config)

// dont forget to use the proper serialization settings from the YamlResourceCollection.cs
builder.Services.AddSingleton<RackPeekConfigMigrationDeserializer>(sp =>
{
    var logger = sp.GetRequiredService<
        ILogger<YamlMigrationDeserializer<YamlRoot>>>();

    var deserializerBuilder = new DeserializerBuilder()
        .WithNamingConvention(CamelCaseNamingConvention.Instance)
        .IgnoreUnmatchedProperties();

    var serializerBuilder = new SerializerBuilder()
        .WithNamingConvention(CamelCaseNamingConvention.Instance);

    return new RackPeekConfigMigrationDeserializer(
        sp,
        logger,
        deserializerBuilder,
        serializerBuilder);
});

ThenYamlResourceCollection should have a RackPeekConfigMigrationDeserializer instance injected into the constructor.

then call

root = _deserializer. Deserialize(yaml)

on line 135 instead of

root = await MigrateAsync(root);

The only missing bit now is to determine if a migration is necessary (prior to deserialization), such that we can decide to save a backup copy. (maybe this should be a feature of doc migrator?)

Something like:

public int GetSchemaVersion(string yaml)
{
    try
    {
        var deserializer = _deserializerBuilder.Build();

        var obj = deserializer.Deserialize<Dictionary<object, object>>(yaml);

        if (obj != null &&
            obj.TryGetValue("schemaVersion", out var value) &&
            value != null)
        {
            if (value is int i)
                return i;

            if (value is string s && int.TryParse(s, out var parsed))
                return parsed;
        }

        return 0;
    }
    catch
    {
        return 0;
    }
}

[Timmoth]

Applied finishing touches and merged with #178

Note I also added the ability to specify the 'schemaVersion' property name to doc migrator, so we can continue to use 'version: 1'

I've also opened #179 To finish by setting up a testing structure for migrations