cellsync: a recovering heartbeat that fails is an owed upload

docs/changes/unreleased/2643-recovering-heartbeat-owed-upload.md

@@ -0,0 +1,11 @@
+---
+kind: fixed
+title: A quit while the sync service is down reports the local save again
+pr: 2643
+surface: [chat, engine]
+invalidates:
+  - "After #2381, quitting while the sync service was unreachable could report a chat whose turns were saved on this computer as not saved, because the hold renewal tried before the upload returned its error unclassified. The renewal's failure is now the same owed upload a failed upload reports: saved here, upload pending."
+---
+
+The renewal is the upload's own first step after an outage, so it reports its
+failure the same way.

internal/cellsync/batch.go

@@ -562,7 +562,11 @@ func (b *Batcher) publish(ctx context.Context, head string) error {
 				}
 				return b.resolve(ctx)
 			}
-			return err
+			// THE HEARTBEAT IS THIS PUBLISH'S RELAY STEP, so its failure is the
+			// same owed upload a failed advance reports: the turns are durable
+			// here and only their upload is pending. Returned bare, a quit with
+			// the relay down reported a confirmed local save as lost.
+			return syncwords.UploadFailure(err)
 		}
 	}
 	ex, err := b.Publisher.publish(ctx, &d, head, b.info())

internal/cellsync/batch_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/Agent-Field/codeaf/internal/cell"
 	"github.com/Agent-Field/codeaf/internal/cellstore"
 	"github.com/Agent-Field/codeaf/internal/directory"
+	"github.com/Agent-Field/codeaf/internal/syncwords"
 	"github.com/Agent-Field/codeaf/internal/wireauth"
 )
 
@@ -248,6 +249,25 @@ func TestBatcherRecoversAfterOutageLongerThanLease(t *testing.T) {
 	}
 }
 
+// TestBatcherRecoveringHeartbeatFailureIsAnOwedUpload proves that a heartbeat
+// failing while the batcher recovers reports the same owed upload a failed
+// publish does. The heartbeat is the relay step of that publish: the turns are
+// durable on this computer and only their upload is pending, which is how a
+// quit with the relay down tells a confirmed local save from a lost one.
+func TestBatcherRecoveringHeartbeatFailureIsAnOwedUpload(t *testing.T) {
+	r := newRig(t)
+	b := r.batcher()
+	r.publishFirst(map[string]string{"a": "0"})
+	note(b, r.seal(map[string]string{"a": "1"}))
+
+	r.dirA.set(directory.ErrUnreachable)
+	b.flush(context.Background())
+	err := b.Close(context.Background())
+	if err == nil || !syncwords.UploadPending(err) {
+		t.Fatalf("a recovering publish with the relay down returned %v, want an owed upload", err)
+	}
+}
+
 func TestSkewIsSurfacedOnce(t *testing.T) {
 	r := newRig(t)
 	b := r.batcher()