Fixed fabric-samples/asset-transfer-basic/application-gateway-typescr…

[k3t4ngit]

Fixed fabric-samples/asset-transfer-basic/application-gateway-typescript grpc client type check

[lehors]

Can you please explain what this actually fixes? Are you getting an error or warning?
I don't see any issues running this code (the original one) and we have this kind of code in a lot of other places in fabric-samples so if we need to fix it we should probably fix it throughout the repo.

[denyeart]

@bestbeforetoday Can you take a look?

[k3t4ngit]

The connect method from @hyperledger/fabric-gateway expects GrpcClient obj as parameter.
But the '@grpc/grpc-js' client is not of type GrpcClient.
I have to cast the type to compile.

[bestbeforetoday]

This change really should not be necessary, and is certainly not a desirable change. Typings should be correct rather than explicitly force potentially incompatible type conversions using unknown.

The fabric-gateway connect() function was changed to take a GrpcClient interface since changes to the private internals of the grpc-js Client class could break type compatibility if the application's version of grpc-js differed from the one used when packaging fabric-gateway. The interface describes only the public members of the grpc-js Client class to minimise these issues. See hyperledger/fabric-gateway#555.

It does seem that some of the grpc-js classes referred to in the GrpcClient interface can also suffer from version-to-version type compatibility issues between different versions of grpc-js. To minimise this problem, grpc-js was removed as a direct dependency of the sample application, and the application instead relies on exactly the version of grpc-js resolved as a dependency of fabric-gateway.

Running locally from a clean environment and using the latest state of the fabric-samples main branch, I don't see any issues. npm install and npm start both run cleanly for me without this change. Running npm ls @grpc/grpc-js gives me this output:

asset-transfer-basic@1.0.0
└─┬ @hyperledger/fabric-gateway@1.2.2
  ├── @grpc/grpc-js@1.8.14
  └─┬ @hyperledger/fabric-protos@0.2.0
    └── @grpc/grpc-js@1.8.14 deduped

If you do see typing issues, it would be good to understand how they have happened and with what package versions, not to just apply unsafe casts to the code.

[denyeart]

Based on bestbeforetoday comments, I'll go ahead and close.