Restore support for generate-metadata false

[maorleger]

I think this PR broke the scenario where a user explicitly passes false to generate-metadata which should be honored. Keyvault is a prime example of this https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/keyvault/keyvault-admin/package.json#L45 . As a result, it's not possible to codegen for keyvault without additional manual steps.

Can we restore support for when the user explicitly passes false?

Originally posted by @maorleger in #3317 (comment)

[maorleger]

If this was done to fix automation consider making this change in the automation pipeline instead (passing generate-metadata=true) or consider supporting generate-metadata=false - but if the user explicitly provides an emitter option it should be honored

[kazrael2119]

in this command https://github.com/Azure/azure-sdk-for-js/blob/main/sdk/keyvault/keyvault-admin/package.json#L45
I tried to run this command and found that this command will use /sdk/keyvault/keyvault-admin/src/generated as the root path which means the generated code would be like

--src
  --generated
     --src
        -- api

because the root path is src/generated and it doesn't have package.json, the generate-metadata will be true
I think we can add a condition that use #3317 only the root path is xx/xx/xx/azure-sdk-for-js

@qiaozha please let me know if you have any concerns thanks

[maorleger]

@kazrael2119 thanks for looking! My 2 cents is that it's almost never ok to ignore CLI options explicitly provided by the user so rather than add more conditions and logic you might consider giving CLI options the highest precedence, and then:

1. Use that CLI option to set generate-metadata true in automation or
2. Enforce generate-metadata true (or omitted) in tspconfig.yaml as keyvault is already doing because of [BUG] [JS SDK] generateMetadata cannot be set to false under @azure-tools/typespec-ts azure-rest-api-specs#31610
3. Fix [BUG] [JS SDK] generateMetadata cannot be set to false under @azure-tools/typespec-ts azure-rest-api-specs#31610 so this scenario is supported

With that said, I'll be happy with anything that restores my ability to codegen keyvault 😄

[kazrael2119]

@maorleger These two issues is because in automation, it will clean up whole library before do the generation. So if your generate-metadata is false, it will not generate package.json which will fails the build step. Therefore I do this fix #3317 in codegen to check if packageJson exists. if you directly use tsp-client, it wouldn't clean up whole library, so generate-metadata will be false as packageJson exists.

For keyvault-admin, this is a special case that it's output path is sdk/keyvault/keyvault-admin/src/generated not sdk/keyvault/keyvault-admin which causes generate-metadata becoming true by calculating whether packageJson exists

FYI, we plan to improve the automation to only clean up src code for dataplane typespec generation in local and release mode, but it will still clean up in specPR mode

[maorleger]

For sure - I understand how it works I am just saying that I worry this was the wrong approach. This is not blocking yet but when the Azure KeyVault service team takes ownership over the SDK I'd prefer to leave them in a good state. Do we have an ETA for a fix?

[maorleger]

I ended up going with the customization-v2 approach for keyvault, so I no longer need this to be fixed just FYI - feel free to close