mesh-controller/internal/link/deadletters_module_stream_test.go

package link

import (
	"strings"
	"testing"

	"github.com/novox/mesh-controller/internal/broker"
)

// A message given up on a module's own stream is delivered again on EVENTS to the consumer that gave it up,
// and only while that consumer is still granted it (novox/hq ADR 0363 §7).
func TestAModuleStreamsDeadLetterGoesBackOnlyWhileGranted(t *testing.T) {
	js := aBus(t)
	mail := broker.ModuleStream{Module: "mesh-mail", Name: "MAIL", Events: []string{"mail.*.message.added"},
		MaxAgeDays: 7, MaxMiB: 16, Restricted: true}
	if err := js.EnsureStream(mail.Stream()); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = js.Context().DeleteStream("MAIL") })
	subject := broker.ModuleStreamSubject("mesh-mail", "mail.mesh.message.added")
	heard := broker.Heard{Stream: "MAIL", Emitter: "mesh-mail", Filters: []string{subject}}
	reader := broker.Principal{Kind: broker.KindModule, Node: "ace", Module: "reader", Hears: []broker.Heard{heard},
		PasswordHash: "x"}
	users := broker.ConsumersOf([]broker.Principal{reader})
	if len(users) != 2 {
		t.Fatalf("the reader's consumers: %+v", users)
	}
	for _, c := range users {
		if err := js.EnsureConsumer(c.Consumer); err != nil {
			t.Fatal(err)
		}
	}
	d := DeadLetter{ID: 9, Stream: "MAIL", Consumer: "ace_reader", Subject: subject}
	got, err := AgainTo(js.Context(), d)
	if err != nil {
		t.Fatal(err)
	}
	if got != broker.AgainSubject("ace_reader", subject) {
		t.Fatalf("delivered again on %s", got)
	}

	if err := js.RemoveConsumer("MAIL", "ace_reader"); err != nil {
		t.Fatal(err)
	}
	if _, err := AgainTo(js.Context(), d); err == nil || !strings.Contains(err.Error(), "no longer hears MAIL") {
		t.Fatalf("delivered again to a consumer no longer granted: %v", err)
	}
}