session_test.go

package qi

import (
	"errors"
	"testing"

	"github.com/iamseth/yin"
)

const (
	testPeerA = yin.ReplicaID("peer-a")
	testPeerB = yin.ReplicaID("peer-b")
)

func TestSessionGenerationScopedCatchUpAndIdempotence(t *testing.T) {
	source := mustNewJSONFile(t, "replica-a")
	mustSet(t, source, "greeting", []byte(`"hello"`))
	sender := NewSession(source)
	artifact, ok, err := sender.ExtractDeltaFor(testPeerB)
	if err != nil || !ok {
		t.Fatalf("ExtractDeltaFor() = (_, %v, %v), want ok", ok, err)
	}
	if sender.Cursor(testPeerB).Version.Get("replica-a") != 0 {
		t.Fatal("extraction advanced cursor")
	}

	receiver := mustNewJSONFile(t, "replica-b")
	session := NewSession(receiver)
	changed, err := session.ApplyDeltaFrom(testPeerA, artifact)
	if err != nil || !changed {
		t.Fatalf("ApplyDeltaFrom() = (%v, %v), want changed", changed, err)
	}
	if !session.Cursor(testPeerA).Version.Equal(source.Version()) {
		t.Fatal("sender cursor was not marked")
	}
	changed, err = session.ApplyDeltaFrom(testPeerA, artifact)
	if err != nil || changed {
		t.Fatalf("duplicate ApplyDeltaFrom() = (%v, %v), want no-op", changed, err)
	}
}

func TestSessionRejectsOldGenerationCursorAndDelta(t *testing.T) {
	identity := DocumentIdentity{DocumentID: "doc", Generation: 2}
	session := NewSessionForDocument(mustNewJSONFile(t, "replica-a"), identity)
	oldCursor := Cursor{Identity: DocumentIdentity{DocumentID: "doc", Generation: 1}}
	if err := session.SetCursor(testPeerB, oldCursor); !errors.Is(err, ErrGenerationMismatch) {
		t.Fatalf("SetCursor() error = %v, want generation mismatch", err)
	}
	_, err := session.ApplyDeltaFrom(testPeerB, DeltaArtifact{Identity: oldCursor.Identity, Payload: []byte(`not-yin`)})
	if !errors.Is(err, ErrGenerationMismatch) {
		t.Fatalf("ApplyDeltaFrom() error = %v, want generation mismatch before decode", err)
	}
}

func TestSessionMalformedCurrentGenerationDelta(t *testing.T) {
	session := NewSession(mustNewJSONFile(t, "replica-a"))
	identity := session.Cursor(testPeerB).Identity
	changed, err := session.ApplyDeltaFrom(testPeerB, DeltaArtifact{Identity: identity, Payload: []byte(`{`)})
	if changed || !errors.Is(err, ErrMalformedSyncArtifact) || !errors.Is(err, yin.ErrMalformedDelta) {
		t.Fatalf("ApplyDeltaFrom() = (%v, %v), want qi and yin malformed errors", changed, err)
	}
	if len(session.Cursor(testPeerB).Version.Counters()) != 0 {
		t.Fatal("malformed delta advanced cursor")
	}
}