protoc-gen-moq

protoc-gen-moq is a plugin of the Google protocol buffers compiler protoc. It reads protobuf service definitions and generates a mocked service client structs. It generates its mocked struct using the matryer/moq template.

How to use it ?

You first need to install the plugin by placing it in your $PATH:

$ go install github.com/alexandrevilain/protoc-gen-moq@latest

Make sure that your $GOBIN is in your $PATH.

Then run it with protoc alongside the protoc-gen-go-grpc plugin:

$ protoc \
	--go_out=. \
	--go_opt=paths=source_relative \
	--go-grpc_out=. \
	--go-grpc_opt=paths=source_relative \
	--moq_out=. \
	--moq_opt=paths=source_relative \
   	hello.proto

Running tests

To run both unit and conformance tests run:

$ make test

Why not using the template package of github.com/matryer/moq ?

I can't use the template package from moq for two reasons:

• the template package is inside the internal package which prevents external usage of the code inside.
• the template package makes an extensive usage of go/types which is not used by protogen.

To ensure the 100% compatibility between struct generated by protoc-gen-moq and moq I created conformance tests which generate the mock for https://github.com/grpc/grpc-go/blob/master/test/grpc_testing/test.proto. The rendered moq file is then checked using go vet which will report an error if the generated struct does not implement the interface methods.