Please write a document describing how to test a chaincode in golang

[bh4rtp2023]

In fabric-samples, chaincode-go is tested using counterfeiter. Does fabric-contract-api-go use mockery? Testing a chaincode is very important, but I cannot find any material describing this topic. Please share a document about it. Thanks.

[bestbeforetoday]

When they are invoked, transaction functions are passed a contractapi.TransactionContextInterface. For unit testing, you can provide your own TransactionContextInterface implementation: the provided contractapi.TransactionContext struct (which has setters to populate its state), one written by hand, or one generated using any mocking framework of your choice.

Transaction functions interact with the ledger using a shim.ChaincodeStubInterface, which they obtain from the transaction context's GetStub() method. Again, this is an interface and for unit testing you can provide your own ChaincodeStubInterface implementation, either written by hand or generated using any mocking framework of your choice.

[bh4rtp2023]

@bestbeforetoday Thank you for instant reply. Can MockStub be reused for unit testing chaincode using contractapi?

[bestbeforetoday]

I am not sure exactly which MockStub implementation you are referring to. If you mean the one that used to be included in fabric-chaincode-go, that should work but be aware that it was deprecated some time ago and is removed from the v2 implementation. I would probably use a mocking framework (such as Mockery) to generate mock implementations of the interfaces. This is the approach used within this repository for unit testing the API. Other mocking frameworks are available that can work just as well. Pick whatever suits you best.