Artifact [9326b15eab]

Artifact 9326b15eab710632e889722a14e619a0c9c56a4467fe8d8639f70a98e70c448b:

• File hub/nats_transport_test.go — part of check-in [6f9e3e40d0] at 2026-05-12 20:27:38 on branch trunk — feat(hub): cross-leaf fossil sync over NATS (#156) (#157)

  Add Config.ProjectCode + Config.SeedFromUpstream so multiple hubs sharing a project-code propagate commits over a single .sync subject. Adds an auto-publish notification on a sibling .commit subject + pull-on-notify subscriber, closing the cross-process Fossil sharing gap from #156.

  - hub/nats_transport.go: libfossil.Transport over nats request/reply - hub/clone.go: HTTP-based SeedFromUpstream helper (NATS-clone deferred) - hub/repo.go: Repo.publish hook fired after successful Commit - hub/hub.go: startCommitSubscriber + Config plumbing + NoEcho - hub/cross_leaf_test.go: gold-path propagation, subject alignment, drift guard - libfossil pin -> v0.6.1 (CreateOpts.ProjectCode)

  Design: docs/superpowers/specs/2026-05-12-cross-leaf-fossil-sync-design.md Protocol: docs/architecture/sync-protocol.md ("NATS-Wrapped Sync")

  Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com> (user: [email protected], size: 2883) [annotate] [blame] [check-ins using]

package hub

import (
	"context"
	"testing"
	"time"

	_ "github.com/danmestas/libfossil/db/driver/modernc"
	"github.com/nats-io/nats.go"
)

// TestNATSTransport_RoundTrip exercises the request/reply path end-to-end
// against an embedded NATS server: a fake responder echoes the payload
// with a known prefix; the transport hands the response back unchanged.
func TestNATSTransport_RoundTrip(t *testing.T) {
	h := newTestHub(t)

	nc, err := nats.Connect(h.NATSURL(), nats.Timeout(2*time.Second))
	if err != nil {
		t.Fatalf("nats.Connect: %v", err)
	}
	defer nc.Close()

	const subject = "fossil.test.sync"
	sub, err := nc.Subscribe(subject, func(msg *nats.Msg) {
		_ = msg.Respond(append([]byte("REPLY:"), msg.Data...))
	})
	if err != nil {
		t.Fatalf("Subscribe: %v", err)
	}
	defer sub.Unsubscribe()
	if err := nc.FlushTimeout(time.Second); err != nil {
		t.Fatalf("Flush: %v", err)
	}

	tr := newNATSTransport(nc, subject, 5*time.Second)
	got, err := tr.RoundTrip(context.Background(), []byte("hello"))
	if err != nil {
		t.Fatalf("RoundTrip: %v", err)
	}
	if string(got) != "REPLY:hello" {
		t.Errorf("RoundTrip response = %q, want %q", string(got), "REPLY:hello")
	}
}

// TestNATSTransport_EmptyReplyIsError asserts the contract that an
// empty reply body (the hub's HandleSync failure signal) surfaces as
// an error rather than being silently treated as a valid no-op.
func TestNATSTransport_EmptyReplyIsError(t *testing.T) {
	h := newTestHub(t)

	nc, err := nats.Connect(h.NATSURL(), nats.Timeout(2*time.Second))
	if err != nil {
		t.Fatalf("nats.Connect: %v", err)
	}
	defer nc.Close()

	const subject = "fossil.test.empty"
	sub, err := nc.Subscribe(subject, func(msg *nats.Msg) {
		_ = msg.Respond([]byte{})
	})
	if err != nil {
		t.Fatalf("Subscribe: %v", err)
	}
	defer sub.Unsubscribe()
	if err := nc.FlushTimeout(time.Second); err != nil {
		t.Fatalf("Flush: %v", err)
	}

	tr := newNATSTransport(nc, subject, 2*time.Second)
	if _, err := tr.RoundTrip(context.Background(), []byte("ping")); err == nil {
		t.Fatal("RoundTrip on empty reply: expected error, got nil")
	}
}

// TestNATSTransport_TimeoutHonored asserts that a non-responsive subject
// causes RoundTrip to error within the transport's configured timeout
// rather than blocking indefinitely.
func TestNATSTransport_TimeoutHonored(t *testing.T) {
	h := newTestHub(t)

	nc, err := nats.Connect(h.NATSURL(), nats.Timeout(2*time.Second))
	if err != nil {
		t.Fatalf("nats.Connect: %v", err)
	}
	defer nc.Close()

	tr := newNATSTransport(nc, "fossil.test.silent", 200*time.Millisecond)
	start := time.Now()
	_, err = tr.RoundTrip(context.Background(), []byte("ping"))
	elapsed := time.Since(start)
	if err == nil {
		t.Fatal("RoundTrip against silent subject: expected error, got nil")
	}
	if elapsed > time.Second {
		t.Errorf("RoundTrip took %v with 200ms timeout — timeout not honored", elapsed)
	}
}