fix(core): commit undo before compaction (#46383)

Co-authored-by: vimtor <36263538+vimtor@users.noreply.github.com>

packages/core/src/session/session.ts

@@ -278,7 +278,8 @@ export const make = Effect.fn("Session.make")(function* (servicesFor: (ref: Loca
     sessionID: SessionSchema.ID,
     input: { id?: SessionMessage.ID; delivery?: SessionInbox.Delivery },
   ) {
-    yield* get(sessionID)
+    const session = yield* get(sessionID)
+    if (session.revert) yield* SessionRevert.commit(bus, session)
     const inputID = input.id ?? SessionMessage.ID.create()
     const admitted = yield* admission
       .admitCompaction({

packages/core/test/session-compact.test.ts

@@ -130,4 +130,41 @@ describe("Session.compact", () => {
       expect(yield* session.inbox(created.id)).toHaveLength(1)
     }),
   )
+
+  it.effect("commits a staged revert before admitting manual compaction", () =>
+    Effect.gen(function* () {
+      const session = yield* Session.Service
+      const bus = yield* Bus.Service
+      const created = yield* session.create({ location })
+      const messageID = SessionMessage.ID.create()
+
+      yield* bus.publish(SessionEvent.InboxEnqueued, {
+        sessionID: created.id,
+        inboxID: messageID,
+        item: {
+          type: "user",
+          payload: { text: "Undo this prompt before compacting." },
+          delivery: "steer",
+        },
+      })
+      yield* bus.publish(SessionEvent.InboxDelivered, {
+        sessionID: created.id,
+        inboxID: messageID,
+      })
+      yield* bus.publish(SessionEvent.RevertEvent.Staged, {
+        sessionID: created.id,
+        revert: { messageID, files: [] },
+      })
+
+      expect((yield* session.get(created.id)).revert?.messageID).toBe(messageID)
+
+      const compacted = yield* session.compact({ sessionID: created.id })
+
+      expect((yield* session.get(created.id)).revert).toBeUndefined()
+      expect(yield* session.context(created.id)).toEqual([])
+      expect(yield* session.inbox(created.id)).toEqual([
+        expect.objectContaining({ id: compacted.id, type: "compaction" }),
+      ])
+    }),
+  )
 })