package link

import (
	"strings"
	"testing"
)

// **The old bus announces a build under both names, and that is not belt-and-braces.**
//
// A build's outcome belongs to the role now, so a catalogue built from the current manifests listens
// for the role's name — and a catalogue already running listens for the module's, because that is what
// it was told when it was installed. A rename on a live bus needs publisher and subscriber to change
// together, which a deployment cannot promise: one arrives first, and in that window the module graph
// silently stops being updated.
//
// Caught by asking what merging this would do to the mesh that is actually running, which is the only
// place the question could have been asked — the tests were green and both buses were self-consistent.
func TestTheOldBusAnnouncesABuildUnderBothNames(t *testing.T) {
	// The routing key a catalogue installed before the change is bound to.
	if KeyModuleBuilt != "module.builder.built" {
		t.Fatalf("the module's own name is %q; a catalogue already running is bound to the old one",
			KeyModuleBuilt)
	}
	// And the local name a catalogue built from the current manifests declares, which the old bus's
	// client turns into `module.<role>.built`.
	if KeyRoleBuilt != "built" {
		t.Fatalf("the role's event is %q, and a holder emits its verbs bare", KeyRoleBuilt)
	}
	if TheBuildMachine != "mesh-build-machine" {
		t.Fatalf("the role is %q", TheBuildMachine)
	}
	// The two must differ, or one publish would serve both and this doubling would be pointless.
	if strings.HasSuffix(KeyModuleBuilt, "."+TheBuildMachine+"."+KeyRoleBuilt) {
		t.Fatal("the two names are the same, so nothing was renamed and this is dead weight")
	}
}