mesh-sdk/go/catalogue/seats_test.go

package catalogue

import (
	"strings"
	"testing"
)

// Defends novox/hq ADR 0110: a seat is a module assignment from a closed set.

func claimed(claims string) []byte {
	return []byte(`{"module":"thing","version":"1","provides":[{"name":"npm-package-registry","scope":"mesh","credential":{"form":"none"}}],"claims":` + claims + `}`)
}

// The holder of a seat answers among several providers.

func registryShelf() map[string]Manifest {
	return shelf(
		Manifest{Module: "gitea", Version: "1", Provides: FromAnywhere("npm-package-registry"),
			Claims: []Claim{{Name: "npm-package-registry", Scope: ScopeMesh}}},
		Manifest{Module: "verdaccio", Version: "1", Provides: FromAnywhere("npm-package-registry")},
		Manifest{Module: "builder", Version: "1", Requires: []string{"npm-package-registry"}},
	)
}

func twoRegistries() map[string][]Provider {
	return map[string][]Provider{"npm-package-registry": {
		{Node: "anchor", At: "anchor.internal", Module: "gitea"},
		{Node: "archive", At: "archive.internal", Module: "verdaccio"},
	}}
}

func giteaHoldsTheSeat() []Held {
	return []Held{{Claim: "npm-package-registry", Scope: ScopeMesh, Node: "anchor", Module: "gitea"}}
}

func TestTheSeatsHolderAnswersWhenSeveralProvide(t *testing.T) {
	// The whole point: a second registry beside the holder harms nothing, and nobody pins.
	got, err := Resolve(registryShelf(), []string{"builder"}, reachable(),
		World{Offered: twoRegistries(), Held: giteaHoldsTheSeat()})
	if err != nil {
		t.Fatal(err)
	}
	if len(got.Needs) != 1 || got.Needs[0].From != "anchor" {
		t.Fatalf("the seat's holder did not answer: %v", got.Needs)
	}
}

func TestAPinStillWinsOverTheSeat(t *testing.T) {
	// A consumer coupled to one provider's contents has said so, and the seat does not overrule it.
	got, err := Resolve(registryShelf(), []string{"builder"}, reachable(),
		World{Offered: twoRegistries(), Held: giteaHoldsTheSeat(),
			Pinned: map[string]Chosen{"npm-package-registry": {Node: "archive", Module: "verdaccio"}}})
	if err != nil {
		t.Fatal(err)
	}
	if len(got.Needs) != 1 || got.Needs[0].From != "archive" {
		t.Fatalf("the pin was overruled by the seat: %v", got.Needs)
	}
}

func TestWithTheSeatUnheldSeveralProvidersAreStillRefused(t *testing.T) {
	// No seat held is no choice made, and ADR 0009's rule stands: never guessed.
	_, err := Resolve(registryShelf(), []string{"builder"}, reachable(),
		World{Offered: twoRegistries()})
	if err == nil {
		t.Fatal("one of two registries was picked with nobody holding the seat")
	}
	if !strings.Contains(err.Error(), "pin") {
		t.Fatalf("the refusal does not say how to choose: %v", err)
	}
}

func TestTheHolderIsTheModuleNotTheMachine(t *testing.T) {
	// Two modules on one machine could provide the same thing; only the one holding the seat
	// answers. A holder matched by node alone would send consumers to whichever came first.
	providers := []Provider{
		{Node: "anchor", At: "anchor.internal", Module: "verdaccio"},
		{Node: "anchor", At: "anchor.internal", Module: "gitea"},
	}
	holder, held := HolderAmong("npm-package-registry", providers, giteaHoldsTheSeat())
	if !held || holder.Module != "gitea" {
		t.Fatalf("the holder was not told apart from a neighbour: %+v", holder)
	}
}

// The working set is loaded from the store, and an empty load never erases it (novox/hq ADR 0122).
func TestUseSeatsReplacesTheSetButNeverEmptiesIt(t *testing.T) {
	before := Seats()
	defer UseSeats(DefaultSeats()) // restore for other tests, whatever this leaves it as

	// An empty load (store not seeded, or unreadable) leaves the compiled defaults in force.
	UseSeats(nil)
	if len(Seats()) != len(before) {
		t.Fatalf("an empty load changed the set from %d to %d seats", len(before), len(Seats()))
	}
	// A non-empty load replaces it — this is how a rename in the store reaches the lookups.
	UseSeats([]Seat{{Name: "node-firewall", Scope: ScopeNode, Decision: "novox/hq ADR 0122"}})
	if _, known := SeatNamed("node-firewall"); !known {
		t.Fatal("the loaded set did not replace the working set")
	}
	if len(Seats()) != 1 {
		t.Fatalf("the working set is %d seats, not the one that was loaded", len(Seats()))
	}
}

// A former name resolves to the seat it was renamed from (novox/hq ADR 0122), so a manifest's claim
// and a held record naming the old name break nothing after a rename.
func TestAFormerNameResolvesAfterARename(t *testing.T) {
	defer func() { UseSeats(DefaultSeats()); UseAliases(nil) }()
	UseSeats([]Seat{{Name: "git", Scope: ScopeMesh, Delivers: "git", Decision: "novox/hq ADR 0121"}})
	UseAliases(map[string]string{"git": "git"})

	// The old name resolves to the renamed seat.
	if s, ok := SeatNamed("git"); !ok || s.Name != "git" {
		t.Fatalf("the former name did not resolve to the renamed seat: %+v ok=%v", s, ok)
	}
	// And a holder recorded under the old name is still found for the provision the seat delivers.
	providers := []Provider{{Node: "anchor", At: "anchor.internal", Module: "gitea"}}
	held := []Held{{Claim: "git", Scope: ScopeMesh, Node: "anchor", Module: "gitea"}}
	holder, found := HolderAmong("git", providers, held)
	if !found || holder.Module != "gitea" {
		t.Fatalf("the holder recorded under the former name was not matched: %+v found=%v", holder, found)
	}
}