emit x-ms-format dfe in swagger

[pshao25]

This is our design for dfe type #3564. Now autorest emitter doesn't output x-ms-format. We want to output it.

Another question is how should we author the scope if we want to output in swagger?
Should it be

@Azure.ClientGenerator.Core.alternateType(
  {
    identity: "Azure.Core.Expressions.DataFactoryElement",
  }
  , "csharp,autorest"
)
union Dfe<T> {
  T,
  DataFactoryElement,
}

?

[timotheeguerin]

So x-ms-format was never an autorest supported extension but something only csharp extension made use of.
We already had a discussion for some other of those csharp specific formats before and we decided not to add to autorest output #1901

[markcowl]

Why would x-ms-format be needed in swagger? Is there another emitter besides csharp that uses this x-ms-format value? (PowerShell?)

Also, is this only for the DataFactory spec, or are there other specs that use this format?

[pshao25]

Yes, synapse is another RP https://github.com/Azure/azure-rest-api-specs/blob/87b04f547cae6239503033c97dc0c7c26a8d6518/specification/synapse/data-plane/Microsoft.Synapse/stable/2020-12-01/entityTypes/LinkedService.json#L7766

Other SDK emitters don't use dfe type. However, they are all expected to support alternateType. Should we do something in the emitted swagger?

As for PowerShell, I don't have an answer now.

[pshao25]

@JoshLove-msft when do we plan to have def support ready in new generator? If we don't output the x-ms-format in the swagger, we cannot generate SDK from swagger.

[JoshLove-msft]

@pshao25 is there a timeline this is needed for? This is currently planned to be worked on in January.

[pshao25]

@pshao25 is there a timeline this is needed for? This is currently planned to be worked on in January.

This impacts the SDK validation for datafactory, which is in this month. We either

1. Have swagger output x-ms-format dfe so that we could validate from swagger.
2. Have new generator be ready for all the TypeSpec features needed for datafactory.

[pshao25]

So x-ms-format was never an autorest supported extension but something only csharp extension made use of. We already had a discussion for some other of those csharp specific formats before and we decided not to add to autorest output #1901

#1901 is related to duration-constant, how is it related to other formats?

[timotheeguerin]

Because it's another case of x-ms-format where we are not doing anything with it

[markcowl]

I think it's risky to consider an API conversion from swagger to TypeSpec complete if we can't generate an SDK in the new emitter. I think, if emitters are not ready for DFE types, we should not complete the conversion of this spec to typespec.

Separately, it's worth asking the PowerShell/CLI teams about this - they are processing our recently converted specs to create new SDKs based on TypeSpec.

[JoshLove-msft]

We can try to prioritize this to have it done ASAP. In the future, can we have a bit more lead time for features that are required for a specific service migration?

[pshao25]

@markcowl @timotheeguerin we are discussing the Synapse case, which just copies the swagger from ADF. If we are going to generate Synapse SDK from swagger, then we need this format. Will get back to you.