ProgramTestRecordReplay.go

/*

Add an option to ProgramTest framework to allow testing a Pulumi program against mock providers that
replay conversations from a previous run. Think of this as a useful way to test that P->P' program updates behave
identically in a quick-and-easy way.

- Unlike vanilla ProgramTest, on a warm cache the test does not touch the cloud.

- Unlike testing with mocks, there is no need to write mocks. Just record a successful run of the program.

- Fast.. If the program uses ec2.Cluster there is no longer a need to wait 20 min to test the program.

- If the program is non-deterministic or deviates from the recorded behavior, the trace becomes insufficient to power
  a mock provider. That is explcitly out of scope (crash with a good error message). Expecting the basic support to 
  still cover enough pratical use cases.

Example:

*/

func TestMyStack(t *testing.T) {
	integration.ProgramTest(t, &integration.ProgramTestOptions{
		Dir: "my-stack",
		ProviderTrace: &integration.ProviderTrace{
			"aws": "test-data/my-stack/aws.json",
		},
	})
}

/*

Running the test without the trace file present runs the program against the cloud and records the trace.

Running the test again with the trace file present runs the program against the trace to replay.

Implementation notes:

- recording is available via PULUMI_DEBUG_GRPC

- replay may be built with the same format and using gRPC interceptors framework

- Ringo working in this space adapting PACT framework to the problem; opportunities to explore/compare 
  solutions in a shared problem-space

*/