Added Domain support for stream mirroring and sourcing and KV full support for the same.

[darkwatchuk]

Added Sources and Mirror to KV Store Creation

fixes #494

PS nats-io/nats.go#1112

[darkwatchuk]

Due to the difficulty of automating leaf node testing below are examples of tests/usage of mirroring and stream sourcing.

   [Fact]
   public async Task Test_LeafStreamMirrorDomain()
   {
       await using var natsLeaf = new NatsConnection(new NatsOpts { Url = "nats://leaf:4223/", AuthOpts = new NatsAuthOpts { Username = "leaf", Password = "leaf" } });
       await natsLeaf.ConnectAsync();

       var jsContext = new NatsJSContext(natsLeaf);

       var mirroredStream = await jsContext.CreateStreamAsync(new StreamConfig()
       {
           Name = "mirroredStream",
           Mirror = new StreamSource
           {
               Name = "sourceStream1",
               Domain = "hub",
           },
       });
   }

   [Fact]
   public async Task Test_LeafStreamMultiSourceDomain()
   {
       await using var natsLeaf = new NatsConnection(new NatsOpts { Url = "nats://leaf:4223/", AuthOpts = new NatsAuthOpts { Username = "leaf", Password = "leaf" } });
       await natsLeaf.ConnectAsync();

       var jsContext = new NatsJSContext(natsLeaf);

       var mirroredStream = await jsContext.CreateStreamAsync(new StreamConfig()
       {
           Name = "mirroredStreamMulti",
           Sources = [
                   new StreamSource { Name = "sourceStream1", Domain = "hub" },
                   new StreamSource { Name = "sourceStream2", Domain = "hub" }
               ],
       });
   }

   [Fact]
   public async Task Test_LeafKVMirrorDomain()
   {
       await using var natsLeaf = new NatsConnection(new NatsOpts { Url = "nats://leaf:4223/", AuthOpts = new NatsAuthOpts { Username = "leaf", Password = "leaf" } });
       await natsLeaf.ConnectAsync();

       var jsContext = new NatsJSContext(natsLeaf);
       var kvContext = new NatsKVContext(jsContext);

       var mirroredStore = await kvContext.CreateStoreAsync(new NatsKVConfig("mirroredKvTestMirror")
       {
           Mirror = new StreamSource
           {
               Name = "kvTest",
               Domain = "hub",
           },
       });
   }

   [Fact]
   public async Task Test_LeafKVMirrorSourcesDomain()
   {
       await using var natsLeaf = new NatsConnection(new NatsOpts { Url = "nats://leaf:4223/", AuthOpts = new NatsAuthOpts { Username = "leaf", Password = "leaf" } });
       await natsLeaf.ConnectAsync();

       var jsContext = new NatsJSContext(natsLeaf);
       var kvContext = new NatsKVContext(jsContext);

       var mirroredStore = await kvContext.CreateStoreAsync(new NatsKVConfig("mirroredKvTestSources")
       {
           Sources = [
                   new StreamSource { Name = "kvTest", Domain = "hub" },
           ],
       });
   }

[darkwatchuk]

Object stores don't seem to support mirroring so this has not been included as previously discussed.

[mtmk]

Due to the difficulty of automating leaf node testing below are examples of tests/usage of mirroring and stream sourcing.

• see Tests/usage of mirroring and stream sourcing #634

[mtmk]

LGTM thanks @darkwatchuk

[mtmk]

@rickdotnet @Jarema I wouldn't mind an extra LGTM here please since I did make a few changes myself as well 😅

[rickdotnet]

Your changes LGTM, @mtmk. The CreateStreamConfig() method is a a beast. 😆

Could also get a shallow copy from records using with { }, but that's new age trickery. 😉

[mtmk]

The CreateStreamConfig() method is a a beast. 😆

hehe true. we can write more tests for it maybe?

Could also get a shallow copy from records using with { }, but that's new age trickery. 😉

ah that's a good point. do you think we should use that to keep models clean? @darkwatchuk and I had a quick discussion about keeping them clean as well.

[rickdotnet]

do you think we should use that to keep models clean?

That'd be a by-product, but essentially. If we had a mixed bag of classes/records and wanted a consistent experience, I'd opt to keep the ShallowCopy() method.

mirror = config.Mirror.ShallowCopy();

vs

mirror = config.Mirror with { };

Both feel good to me.

[mtmk]

do you think we should use that to keep models clean?

That'd be a by-product, but essentially. If we had a mixed bag of classes/records and wanted a consistent experience, I'd opt to keep the ShallowCopy() method.

mirror = config.Mirror.ShallowCopy();

vs

mirror = config.Mirror with { };

Both feel good to me.

I think with syntax is good especially when there are properties updated. Updated!

[rickdotnet]

Nice, looks good to me!

[mtmk]

Looks like we're missing some of reference implementation details here:

https://github.com/nats-io/nats.go/blob/94fa0cb99411c202a4c9c2ae84f444a10f2e5ad8/kv.go#L1182-L1193

cc @Jarema

[mtmk]

Double checked the implementation against nats-io/nats.go#1112 (with latest changes in main) Looks good. Only, some of the mirror bucket mapping seems to be missing which is captured in #642 and can be handled in a follow up PR