| 1 | import assert from "node:assert/strict"; |
| 2 | import { TranscriptStore } from "../../lib/transcriptStore"; |
| 3 | import type { HistoryContentChunk, HistorySlice } from "../../lib/types"; |
| 4 | |
| 5 | function deferred<T>() { |
| 6 | let resolve!: (value: T) => void; |
| 7 | const promise = new Promise<T>(done => { resolve = done; }); |
| 8 | return { promise, resolve }; |
| 9 | } |
| 10 | |
| 11 | export async function verifyTranscriptContentOwnership() { |
| 12 | const slice = (revision: number): HistorySlice => ({ |
| 13 | entries: [{ entryId: "m:answer", turn: 1, order: 0, |
| 14 | message: { role: "assistant", content: `preview-${revision}` }, |
| 15 | refs: [{ entryId: "m:answer", field: "content", size: 100, chunks: 1, revision, digest: `cut-${revision}` }] }], |
| 16 | revision, revisionKnown: true, digest: `cut-${revision}`, stale: false, |
| 17 | nextCursor: "", hasOlder: false, totalTurns: 1, startTurn: 1, endTurn: 1, |
| 18 | }); |
| 19 | const chunk = (data: string): HistoryContentChunk => ({ |
| 20 | entryId: "m:answer", field: "content", chunk: 0, chunks: 1, data, done: true, stale: false, |
| 21 | }); |
| 22 | function fixture() { |
| 23 | const requests: { revision: number; gate: ReturnType<typeof deferred<HistoryContentChunk>> }[] = []; |
| 24 | const started = [deferred<void>(), deferred<void>()]; |
| 25 | const page = deferred<HistorySlice>(); |
| 26 | const store = new TranscriptStore({ |
| 27 | HistorySliceForTab: () => page.promise, |
| 28 | HistoryContentForTab: async (_tab, ref) => { |
| 29 | const gate = deferred<HistoryContentChunk>(); |
| 30 | requests.push({ revision: ref.revision, gate }); |
| 31 | started[requests.length - 1]?.resolve(); |
| 32 | return gate.promise; |
| 33 | }, |
| 34 | }); |
| 35 | store.noteSessionBinding("tab", "/session", "session-generation-1"); |
| 36 | store.installSlice("tab", "/session", slice(1)); |
| 37 | const read = () => store.requestFullContent("tab", "m:answer", "content"); |
| 38 | return { store, requests, page, read, started }; |
| 39 | } |
| 40 | { |
| 41 | const { store, requests, read } = fixture(); |
| 42 | const pending = read(); |
| 43 | assert.equal(store.noteSessionBinding("tab", "/session", "session-generation-1"), false); |
| 44 | assert.ok(store.peek("tab", "/session"), "the same binding retains its resident window"); |
| 45 | assert.equal(store.noteSessionBinding("tab", "/session", "session-generation-2"), true); |
| 46 | assert.equal(store.peek("tab", "/session"), undefined, "same-path rebind invalidates the old cache before reading"); |
| 47 | store.installSlice("tab", "/session", slice(2)); |
| 48 | requests[0].gate.resolve(chunk("obsolete")); |
| 49 | assert.equal(await pending, undefined, "a binding replacement cannot hand old body reads to the new session"); |
| 50 | assert.equal(requests.length, 1); |
| 51 | } |
| 52 | { |
| 53 | const { store, requests, read, started } = fixture(); |
| 54 | const pending = read(); |
| 55 | store.installSlice("tab", "/session", slice(2)); |
| 56 | requests[0].gate.resolve(chunk("obsolete")); |
| 57 | await started[1].promise; |
| 58 | assert.equal(requests[1]?.revision, 2, "Follow installation hands the original alias to the new cut"); |
| 59 | requests[1].gate.resolve(chunk("current")); |
| 60 | assert.equal(await pending, "current"); |
| 61 | assert.equal(await read(), "current", "resolved body remains resident"); |
| 62 | } |
| 63 | { |
| 64 | const { store, requests, read } = fixture(); |
| 65 | const pending = read(); |
| 66 | store.evictTab("tab"); |
| 67 | store.installSlice("tab", "/session", slice(2)); |
| 68 | requests[0].gate.resolve(chunk("obsolete")); |
| 69 | assert.equal(await pending, undefined, "eviction is terminal even when the same tab reopens"); |
| 70 | assert.equal(requests.length, 1, "the old owner never starts a read for the new owner"); |
| 71 | assert.equal(store.peek("tab", "/session")?.items[0]?.kind, "assistant"); |
| 72 | } |
| 73 | { |
| 74 | const { store, requests, page, read, started } = fixture(); |
| 75 | const reload = store.loadLatest("tab", "/session"); |
| 76 | const pending = read(); |
| 77 | assert.equal(requests.length, 0, "a body requested during replacement waits for the new page"); |
| 78 | page.resolve(slice(2)); |
| 79 | await reload; |
| 80 | await started[0].promise; |
| 81 | assert.equal(requests[0]?.revision, 2, "replacement does not read an old ref under a new generation"); |
| 82 | requests[0].gate.resolve(chunk("fresh")); |
| 83 | assert.equal(await pending, "fresh"); |
| 84 | } |
| 85 | { |
| 86 | const { store, requests, read, started } = fixture(); |
| 87 | const pending = read(); |
| 88 | store.installSlice("tab", "/session", slice(2)); |
| 89 | requests[0].gate.resolve(chunk("first")); |
| 90 | await started[1].promise; |
| 91 | store.installSlice("tab", "/session", slice(3)); |
| 92 | requests[1].gate.resolve(chunk("second")); |
| 93 | assert.equal(await pending, undefined, "repeated replacement cannot create an unbounded retry loop"); |
| 94 | assert.equal(requests.length, 2, "one content request has at most one generation handoff"); |
| 95 | } |
| 96 | } |
| 97 |