fix: keep favourites and joins when the server refuses an edit #34

When the server refused an edit made on the device (a book or calendar
that turned read-only, an event in a calendar where only one's own
events may be changed), the engine put the item back by deleting its
rows and inserting a fresh copy. A contact lost its star, ringtone and
the link to the contacts it was joined with; an event got a new row id.

The rows are now rewritten in place from the server's version, as after
an accepted upload. A refused deletion still brings the item back as a
new copy.

src/device-sync/engine/item-sync.ts

@@ -1390,6 +1390,8 @@ export abstract class ItemSync {
       }];
     }
     await this.beforePlanning(acct, [object]);
+    // An edit is undone in place, so what only the device keeps stays: a star, a ringtone, a joined contact, row ids.
+    if (objectKind === kind && !p.meta.deleted) return [this.overwriteWork(acct, kind, local, object)];
     const insert = objectKind.planDownload(object, null, acct);
     return [{
       group: concatGroups(ref, remove, insert.ops),
@@ -1398,6 +1400,23 @@ export abstract class ItemSync {
     }];
   }
 
+  /** The rows become `object` where they are and DIRTY is cleared (the planner's write of an accepted version). */
+  private overwriteWork(acct: string, kind: Kind, local: unknown, object: ServerObject): Work {
+    return {
+      group: kind.planAccepted(local, object, acct).ops,
+      state: this.listing(kind, acct, object.id, true),
+      applied: () => this.onDownloaded(kind, acct, object),
+      replan: async () => {
+        const again = await this.reload(kind, local);
+        return again === null ? null : this.overwriteWork(acct, kind, again, object);
+      },
+      failed: (reason, message) => {
+        this.markStale(acct, object.id);
+        this.env.report.itemError({ ref: refOf(acct, object.id), side: 'upload', type: reason, description: message });
+      },
+    };
+  }
+
   /**
    * `invalidProperties` on `uid`: the object exists (a lost response, or the
    * client's automatic retry of the create). Cards name it in the error;