experimental matchers for integration testing

[ripienaar]

Signed-off-by: R.I.Pienaar [email protected]

[ripienaar]

@vjanelle this is what I was talking about on slack, give me some more ideas of what you want to be testable and I can see.

Ultimately I want to expand this out enough that I can stand up a infra using docker compose and write integration tests against that asserting things like did all servers get correctly provisioned etc

[ripienaar]

Other things I am just kind of thinking about - for the context of testing a deployed infra

• ✅ HaveDiscoverableNodes(count) - discovers using the generated rpc client and asserts against them
• HaveOutputWithValue(output, key, value) - takes any generated client result looking for key and val, those found with res.AllOutputs(), I might add some accessors to find more like by name or something
• HaveAllOutputsWithValue(res, key, value) - loops all the outputs and checks they all have the same key and value, this from any generated client reply

If I can't make this work - or I dont want to require generics - we could look at a generic thing like

Expect(RPC("agent", "action", input, filter)).To(HaveAllRepliesWithValue(key, value)

or

res,err:=RPC("agent", "action", input, filter)
Expect(err).ToNot(HaveOccured())
Expect(res).To(HaveAllRepliesWithValue(key, value)

ie. a small RPC caller helper that doesnt use the generated client - this for testing agents. But I suspect you want to test the clients right?

[ripienaar]

An alternative approach would be to add an assert package to each generated client with things like:

package assert

import (
	"testing"

	"github.com/choria-io/go-choria/client/rpcutilclient"
)

type StatsProvider interface {
	Stats() rpcutilclient.Stats
}

func HaveUnexpectedResponders(t *testing.T, res StatsProvider, count int) {
	ur := len(res.Stats().UnexpectedResponseFrom())
	switch {
	case count < 0:
		if ur == 0 {
			t.Fatalf("Expected >0 unexpected responders")
		}
	case count == 0:
		if ur > 0 {
			t.Fatalf("Expected no unexpected responders")
		}
	default:
		if ur != count {
			t.Fatalf("Expected %d unexpected responders but had %d", count, ur)
		}
	}
}

res, _ := rpcutilClient.AgentInventory().Do(ctx)
assert.HaveUnexpectedResponders(t, res, 0)

This would be usable in any testing framework for go and less casting and weird stuff since it would just use the package internals?

I could even put this in the package directory as AssertHaveUnexpectedResponders() (ie. not on the instance) since then it would have access to the private variables in the client, I think I quite like this it avoids having to pollute the clients with weird accessors