pact-serialization-proxy

Motivation

The Pact testing framework was designed with JSON over HTTP in mind - anyone using non-JSON encodings, and transports other than HTTP are unable to use Pact (with the exception of message pacts which are only suitable for async communication e.g. "put this thing on a queue for me" - even these message pacts often require use of JSON too).

It's desirable to be able to write Pact tests for Protobuf over HTTP or Protobuf over GRPC: just having a "contract" between services, in the form of .proto files isn't sufficient - this contract must be made explicit and verified. Typically testing contracts between services requires either integration tests, or "contract tests", as Pact facilitates - it would be nice to be able to do contract tests

Aims

Short term

To enable testing of Protobuf over HTTP with Pact - for various reasons, that's the setup I'd actually like to test.

Longer term

Enable testing of Protobuf over GRPC: exploratory work has been done which leads me to believe this is possible without too much effort, however as I don't have a direct need for it, contributions are encouraged for this element.

Design

In order to re-use as much of the Pact testing infrastructure as possible, a single new component will be added (pact-serialization-proxy) which will convert between Protobuf and JSON.

More details can be found here.

"High level design diagram":

Status

Currently still a work-in-progress, the following functionality is working with the C# Pact library (more details to come):

• Create a protobuf-based pact for GET requests.
• Verify protobuf-based pacts for GET requests.

The following work is outstanding:

• v0.1 release:
  • Add support for requests which contain non-empty request bodies (POST/PUT).
  • Add logging which allows failures to be debugged more easily.
• v0.2 release:
  • Modularize the code and add unit tests.
  • Ensure failure-cases are tested and behave as expected.
  • Add release deployment code to Travis-CI.
• v1.0 release:
  • Add an integration test between the serialization proxy and the Ruby Core.
  • Add documentation for:
    • How to add language support for the serialization proxy.
    • If accepted, then in the Pact spec and on the Pact website.
• Future release:
  • Support for GRPC.