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Merge newest origin/master into token-meter-service

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This commit is contained in:
Tianyi Cui
2026-07-17 22:49:54 +08:00
parent 35ff333e51 350a636ece
commit 06ea8643ff
106 changed files with 1488 additions and 1353 deletions
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22
packages/core/agent-loop/src/request-log.ts
View File

@@ -1,11 +1,12 @@
/**
* Per-loop-instance request-header bookkeeping for reconstructability. The
* comparison baseline is the header folded from the session log, so a fresh
* loop instance needs no special resume or fork state.
* comparison baseline is folded from the session log; a fresh instance anchors
* it with an initial/resume snapshot and later logs full changed snapshots.
*
* @module dsh-agent-loop/request-log
*/
import { diffHeader, headerEquals, applyHeaderDelta } from '@deepseek-ai/dsh-session'
import { headerEquals } from '@deepseek-ai/dsh-session'
import type { EpochHeader, Session } from '@deepseek-ai/dsh-session'
import type { Message } from '@deepseek-ai/dsh-llm'
@@ -32,10 +33,8 @@ export function createTransmissionLog(): TransmissionLog {
}
/**
* Append whatever header event makes the log reproduce this request's header.
* The first request from an instance always records a full `initial` or `resume`
* snapshot. Later requests record nothing when unchanged, a round-tripping
* delta when expressible, or a full `fallback` snapshot otherwise.
* Append the full header snapshot owed by this request: initial/resume for the
* instance's first request, nothing when unchanged, or change otherwise.
*
* @param session - the session whose log explains the request.
* @param state - this loop instance's bookkeeping (mutated on first log).
@@ -52,12 +51,5 @@ export function recordRequestHeader(session: Session, state: TransmissionLog, he
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const baseline = session.requestHeader()!
if (headerEquals(baseline, header)) return
const delta = diffHeader(baseline, header)
/* v8 ignore next -- headerEquals false ⟹ diffHeader defined: both compare the same four parts */
if (delta === undefined) return
if (headerEquals(applyHeaderDelta(baseline, delta), header)) {
session.append('request/header-delta', delta)
} else {
session.append('request/header', { header, reason: 'fallback' })
}
session.append('request/header', { header, reason: 'change' })
}

6
packages/core/agent-loop/tests/interception.spec.ts
View File

@@ -375,8 +375,8 @@ describe('agent/session-prefix', () => {
expect(request.messages[0]).toEqual(reminder)
}
// The anchoring snapshot is the prefix's durable record — and the ONLY
// header event: reuse means no request/header-delta ever.
const headerEvents = events(agent).filter(e => e.type === 'request/header' || e.type === 'request/header-delta')
// header event: reuse means no changed snapshot ever.
const headerEvents = events(agent).filter(e => e.type === 'request/header')
expect(headerEvents).toHaveLength(1)
expect(headerEvents[0]?.type === 'request/header' && headerEvents[0].data.header.messagePrefix).toEqual([reminder])
// Never session history: the derivation starts at the real user prompt.
@@ -492,7 +492,7 @@ describe('agent/session-prefix', () => {
// cached prefix is a deep-frozen clone, so step 2's request is unchanged.
held.content = [{ type: 'text', text: 'v2' }]
expect(adapter.requests[1]!.messages[0]).toEqual({ role: 'user', content: [{ type: 'text', text: 'v1' }] })
expect(events(agent).filter(e => e.type === 'request/header-delta')).toHaveLength(0)
expect(events(agent).filter(e => e.type === 'request/header')).toHaveLength(1)
})
})

23
packages/core/agent-loop/tests/request-log.spec.ts
View File

@@ -1,9 +1,8 @@
/**
* recordRequestHeader unit tests: exactly one of four things per request —
* recordRequestHeader unit tests: exactly one of three things per request —
* an 'initial' snapshot (log has no header yet), a 'resume' snapshot (fresh
* loop instance over a log that has one), nothing (header unchanged), a
* round-tripping delta, or a 'fallback' snapshot when the delta encoding
* cannot express the change (pure tool reordering).
* loop instance over a log that has one), nothing (header unchanged), or a
* full 'change' snapshot.
*/
import { describe, expect, it } from 'vitest'
@@ -23,7 +22,7 @@ function openSession(id: string): Session {
}
function headerEvents(session: Session): SessionEvent[] {
return session.events.filter(e => e.type === 'request/header' || e.type === 'request/header-delta')
return session.events.filter(e => e.type === 'request/header')
}
describe('recordRequestHeader', () => {
@@ -53,8 +52,8 @@ describe('recordRequestHeader', () => {
expect(events[1]?.type === 'request/header' && events[1].data.reason).toBe('resume')
})
it('logs a round-tripping delta for a mid-run change, and the fold reproduces the header', () => {
const session = openSession('rl-delta')
it("logs a full 'change' snapshot for a mid-run change, and the fold reproduces the header", () => {
const session = openSession('rl-change')
const state = createTransmissionLog()
const first = canonicalHeader({ config: { provider: 'mock', model: 'm' }, system: 'a\nb', tools: [tool('t')] })
recordRequestHeader(session, state, first)
@@ -63,12 +62,12 @@ describe('recordRequestHeader', () => {
recordRequestHeader(session, state, second)
const events = headerEvents(session)
expect(events).toHaveLength(2)
expect(events[1]?.type).toBe('request/header-delta')
expect(events[1]?.type === 'request/header' && events[1].data.reason).toBe('change')
expect(session.requestHeader()).toEqual(second)
})
it("records a change the delta cannot express (pure reordering) as a 'fallback' snapshot", () => {
const session = openSession('rl-fallback')
it("records a pure tool reordering as a 'change' snapshot", () => {
const session = openSession('rl-reorder')
const state = createTransmissionLog()
const first = canonicalHeader({ config: { provider: 'mock', model: 'm' }, tools: [tool('a'), tool('b')] })
recordRequestHeader(session, state, first)
@@ -77,9 +76,7 @@ describe('recordRequestHeader', () => {
recordRequestHeader(session, state, reordered)
const events = headerEvents(session)
expect(events).toHaveLength(2)
expect(events[1]?.type === 'request/header' && events[1].data.reason).toBe('fallback')
// The fold still lands on the exact header — deltas are an encoding
// optimization, never a correctness dependency.
expect(events[1]?.type === 'request/header' && events[1].data.reason).toBe('change')
expect(session.requestHeader()).toEqual(reordered)
})
})

28
packages/core/agent-loop/tests/request-reconstruction.spec.ts
View File

@@ -1,9 +1,8 @@
/**
* Loop-level reconstructability: every request the loop sends is a pure function of the
* session log — messages are the derivation at the step/start boundary, the header is the fold
* of request/header* events — and every request is an append-extension of its predecessor
* unless a logged event (compaction replace, header change) explains the difference. Mock-adapter
* requests are the observable, and the final offline rebuild states the full contract end to end.
* session log — messages derive at the step/start boundary and the header is the latest
* request/header snapshot. Each request extends its predecessor unless a logged compaction
* replacement or header change explains the difference.
*/
import { describe, expect, it } from 'vitest'
@@ -85,7 +84,7 @@ describe('request stability across the loop', () => {
expect(Object.isFrozen(request.messages)).toBe(true)
}
// One anchoring header snapshot; no further header events (nothing changed).
const headerEvents = agent.session.events.filter(e => e.type === 'request/header' || e.type === 'request/header-delta')
const headerEvents = agent.session.events.filter(e => e.type === 'request/header')
expect(headerEvents).toHaveLength(1)
expect(headerEvents[0]?.type === 'request/header' && headerEvents[0].data.reason).toBe('initial')
})
@@ -122,8 +121,8 @@ describe('request stability across the loop', () => {
content: [{ type: 'text', text: '[summary of turn 1]' }],
source: { kind: 'plugin', plugin: 'test-compact' },
}, {
surfaceOp: { op: 'replace', start: nodes[0]!.seq, end: nodes[1]!.seq },
sourceEventSeqs: [nodes[0]!.seq, nodes[1]!.seq],
surfaceOp: { op: 'replace', start: nodes[0]!, end: nodes[1]! },
sourceEventSeqs: [nodes[0]!, nodes[1]!],
})
})
@@ -137,7 +136,7 @@ describe('request stability across the loop', () => {
expect(agent.session.events.filter(e => e.type === 'request/header')).toHaveLength(1)
})
it('a real system-prompt change is a logged header delta; a stable prompt logs nothing', async () => {
it('a real system-prompt change is a full changed-header snapshot; a stable prompt logs nothing', async () => {
const adapter = new MockAdapter([textResponse('one'), textResponse('two'), textResponse('three')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { provider: 'mock', model: 'mock' })
@@ -147,14 +146,15 @@ describe('request stability across the loop', () => {
send(agent, 'second')
await waitForIdle(ctx, agent)
// Identical assembly re-rendered per step is NOT a change.
expect(agent.session.events.filter(e => e.type === 'request/header-delta')).toHaveLength(0)
expect(agent.session.events.filter(e => e.type === 'request/header')).toHaveLength(1)
ctx.systemPrompt.section({ name: 'extra', order: 2, text: 'new guidance' })
send(agent, 'third')
await waitForIdle(ctx, agent)
const deltas = agent.session.events.filter(e => e.type === 'request/header-delta')
expect(deltas).toHaveLength(1)
const snapshots = agent.session.events.filter(e => e.type === 'request/header')
expect(snapshots).toHaveLength(2)
expect(snapshots[1]?.data.reason).toBe('change')
expect(adapter.requests[2]!.system).toContain('new guidance')
// History is preserved across the change — only the header moved.
expect(adapter.requests[2]!.messages.length).toBeGreaterThan(adapter.requests[1]!.messages.length)
@@ -260,9 +260,9 @@ describe('request stability across the loop', () => {
send(agent, 'second')
await waitForIdle(ctx, agent)
// No delta was logged (nothing really changed), and the session's own
// No changed snapshot was logged (nothing really changed), and the session's own
// fold is immutable state.
expect(agent.session.events.filter(e => e.type === 'request/header-delta')).toHaveLength(0)
expect(agent.session.events.filter(e => e.type === 'request/header')).toHaveLength(1)
expect(Object.isFrozen(agent.session.requestHeader())).toBe(true)
expect(adapter.requests[1]!.temperature).toBeUndefined()
})
@@ -296,7 +296,7 @@ describe('request stability across the loop', () => {
const rebuilt = new Session(SessionId(`rebuild-${index}`), structuredClone(events.slice(0, stepStart.seq)))
expect(structuredClone(request.messages)).toEqual(rebuilt.deriveMessages())
// Header: the fold of request/header* events up to this step's dispatch
// Header: the latest request/header snapshot up to this step's dispatch
// (its header event sits between step/start and the first chunk).
const firstChunk = events.find(e => e.type === 'assistant/chunk' && e.seq > stepStart.seq)!
const header = foldRequestHeader(events.slice(0, firstChunk.seq))!

21
packages/core/session/README.md
View File

@@ -1,6 +1,6 @@
# dsh-session
Event-sourced session log and in-memory store. A `Session` is the append-only source of truth for an agent's whole interaction history — the LLM message history is *derived* from it. A **surface** layer (a linked list of message-producing events) is maintained on top of the raw log for efficient derivation and compaction.
Event-sourced session log and in-memory store. A `Session` is the append-only source of truth for an agent's whole interaction history — the LLM message history is *derived* from it. A **surface** layer (an ordered projection of message-producing events) is maintained on top of the raw log for efficient derivation and compaction.
## Service: `SessionStore` (ctx key: `sessions`)
@@ -33,7 +33,7 @@ The store pairs announced creation with disposal, publishes post-commit append n
Plain class (not a Cordis Service). Create via `ctx.sessions.create()`.
- `session.append(type, data, opts?)` snapshots and freezes durable data and surface metadata, validates marker shape, provenance, and complete replacement coverage, commits synchronously, then notifies observers with independent failure containment. Reentrant attached-session appends reject, and runtime checks cover widened unions and loaded logs.
- `session.deriveMessages()` incrementally projects each new surface node once and returns a fresh array over shared frozen messages. Assistant projections preserve provider/model provenance and adapter-private replay state. A surface rewrite rebuilds the projection; there is no raw-log fallback.
- `session.deriveMessages()` incrementally projects each new surface entry once and returns a fresh array over shared frozen messages. Assistant projections preserve provider/model provenance and adapter-private replay state. A surface rewrite rebuilds the projection; there is no raw-log fallback.
- `session.deriveEventMessage(event)` is the canonical per-event projection used by reconstruction and invariants.
- `session.surface` lazily folds only new `surfaceOp` markers; `replaceGeneration` changes on every rewrite.
- `session.events` is a cached frozen snapshot invalidated by append; accepted events remain deeply frozen.
@@ -46,15 +46,14 @@ Durable values need one accepted representation, not a check followed by a secon
### Surface types
- `SurfaceOp` — how a surface node entered the linked list: `'append'` (normal tail append) or `{ op: 'replace', start, end }` (replace nodes from `start` through `end` inclusive — both must be valid surface node seqs; `start === end` replaces a single node). Used by compaction to shadow old nodes without deleting them.
- `SurfaceOp` — how an event entered the ordered surface: `'append'` (normal tail append) or `{ op: 'replace', start, end }` (replace entries from `start` through `end` inclusive — both must be valid surface seqs; `start === end` replaces one entry). Used by compaction to shadow old events without deleting them.
- `SurfaceIntent` — `{ surfaceOp: SurfaceOp; sourceEventSeqs?: number[] }`, the required third parameter to `session.append()` for surface-eligible types.
- `SurfaceNode` — `{ seq: number; prev: number | null; next: number | null }`, one node in the surface linked list.
- `foldSurface(events)` — replay the one canonical surface contract into detached current nodes and actual replacement ranges. The same pass rejects non-contiguous event seqs, misplaced or malformed metadata, empty or duplicate provenance, non-earlier sources, invalid positional ranges, and replacements that fail to cite every shadowed surface node; `SurfaceManager` shares the atomic transition while retaining its incremental cache.
- `isSurfaceEvent(event)` / `isSurfaceEligibleType(type)` — the first narrows a `SessionEvent` to a fully-formed surface node (type is surface-eligible AND `surfaceOp` present); the second is the type-only check (is this one of the five `SurfaceEventType` values?), used to detect a surface-eligible event MISSING its marker — e.g. when validating a seed/load log.
- `foldSurface(events)` — replay the canonical surface contract into detached current event sequences and actual replacement ranges. The same pass rejects non-contiguous seqs, misplaced or malformed metadata, empty or duplicate provenance, non-earlier sources, invalid positional ranges, and replacements that fail to cite every shadowed surface entry; `SurfaceManager` shares the atomic transition while retaining only its incremental sequence cache.
- `isSurfaceEvent(event)` / `isSurfaceEligibleType(type)` — the first narrows a `SessionEvent` to a fully formed surface event; the second detects a surface-eligible event missing its marker when validating a seed or loaded log.
### Request-header reconstruction (`request-header.ts`)
`request/header` and `request/header-delta` make the non-history request envelope reconstructable from the log. `foldRequestHeader()` reconstructs the active header, `diffHeader()` encodes changes, and `applyHeaderDelta()` replays them; unsupported deltas fall back to a full snapshot. `messagePrefix` remains separate from derived history. See the [reconstructable-requests RFC](../../../docs/rfc/implemented/architecture/2026-07-05-reconstructable-requests.md).
`request/header` records a full canonical snapshot of the non-history request envelope with reason `initial`, `resume`, or `change`. `foldRequestHeader()` selects the latest snapshot; legacy delta events and the removed `fallback` reason are rejected. `messagePrefix` remains separate from derived history. See the [reconstructable-requests RFC](../../../docs/rfc/implemented/architecture/2026-07-05-reconstructable-requests.md).
`context/message` defaults to the canonical tagged context projection. A producer may set `envelope: 'raw'` when its `content` already contains the complete model-facing frame, and may attach JSON `meta` for replayable plugin state; metadata remains durable but is excluded from `deriveMessages()`.
@@ -68,7 +67,7 @@ Also defines `TurnTriggerMap` and `TurnEndReasonMap` (merge-extensible sum types
Every `SessionEvent` carries two optional top-level fields (structural metadata):
- `sourceEventSeqs?: number[]` — seq numbers of provenance sources (e.g., the `assistant/chunk` seqs behind an `assistant/message`, or the shadowed nodes behind a compaction replace node). On `assistant/message`, a present `[]` records a known empty provider stream, while omission means legacy or otherwise unrecorded provenance; other surface events require a non-empty list when this field is present.
- `sourceEventSeqs?: number[]` — seq numbers of provenance sources (e.g., the `assistant/chunk` seqs behind an `assistant/message`, or the shadowed entries behind a compaction replacement entry). On `assistant/message`, a present `[]` records a known empty provider stream, while omission means legacy or otherwise unrecorded provenance; other surface events require a non-empty list when this field is present.
- `surfaceOp?: SurfaceOp` — how this event entered the surface. Absent for non-surface events (boundaries, chunks, usage, errors).
### Metadata types (`types.ts`)
@@ -79,15 +78,15 @@ Every `SessionEvent` carries two optional top-level fields (structural metadata)
- Persistence plugins: subscribe to `session/event` (write-behind) and drain on `session/flush` (awaited) and fiber dispose. A durable backend reads the log and reloads it into a live session; the metadata seam (`SessionHeader`, `session.header`) is what such a backend stores beside the log.
- Replay/fork: `create(id, { seed })` validates and freezes a contiguous current-format log and rebuilds its surface; request headers require provider/model and assistant messages require provider/model provenance. `fork(source, boundary?, childSessionId?)` selects a completed-turn prefix and records lineage.
- Compaction: the `dsh-compact-basic` plugin appends a `user/message` with `surfaceOp: { op: 'replace', start, end }` to shadow old surface nodes behind a summary checkpoint. Tool-pairing boundary policy and its cache belong to the [`dsh-compact` seam](../../compact/compact/README.md), while this package owns surface membership, positional links, and `replaceGeneration`.
- Compaction: the `dsh-compact-basic` plugin appends a `user/message` with `surfaceOp: { op: 'replace', start, end }` to shadow old surface entries behind a summary checkpoint. Tool-pairing boundary policy and its cache belong to the [`dsh-compact` seam](../../compact/compact/README.md), while this package owns ordered surface membership and `replaceGeneration`.
## Model Experience
### Derived message history
**What the model sees**: The model receives projections of `user/message`, `assistant/message`, and `tool/result` surface nodes verbatim. A `context/message` is a user-role message containing exactly `<context source="<source-kind>">`, its content blocks, and `</context>`; `steering/message` uses the identical `<steering source="<source-kind>">` / `</steering>` wrapper. Tool calls live inside assistant messages. Chunks, boundaries, usage, hook records, todo records, and other log-only events add no message.
**What the model sees**: The model receives projections of `user/message`, `assistant/message`, and `tool/result` surface entries verbatim. A `context/message` is a user-role message containing exactly `<context source="<source-kind>">`, its content blocks, and `</context>`; `steering/message` uses the identical `<steering source="<source-kind>">` / `</steering>` wrapper. Tool calls live inside assistant messages. Chunks, boundaries, usage, hook records, todo records, and other log-only events add no message.
**Token effect**: Appended surface nodes are resent on later steps. A `replace` surface operation removes the shadowed nodes from future inputs without deleting their raw log records.
**Token effect**: Appended surface entries are resent on later steps. A `replace` surface operation removes the shadowed entries from future inputs without deleting their raw log records.
### Crash-repair result

40
packages/core/session/src/index.ts
View File

@@ -22,9 +22,9 @@ export * from './types.ts'
export { isJsonValue, snapshotJsonValue } from './json.ts'
export type { JsonValue } from './json.ts'
export { interruptedTurnClosers } from './repair.ts'
export type { SurfaceFoldReplacement, SurfaceFoldResult, SurfaceNode } from './surface.ts'
export type { SurfaceFoldReplacement, SurfaceFoldResult } from './surface.ts'
export { foldSurface, isSurfaceEvent, isSurfaceEligibleType } from './surface.ts'
export { applyHeaderDelta, canonicalHeader, diffHeader, foldRequestHeader, headerEquals } from './request-header.ts'
export { canonicalHeader, foldRequestHeader, headerEquals } from './request-header.ts'
declare module 'cordis' {
interface Context {
@@ -133,6 +133,9 @@ function snapshotSessionHeader(id: SessionId, source?: SessionHeader): SessionHe
/** Validate the fixed event envelope after one-pass JSON materialization. */
function assertSessionEventEnvelope(value: Record<string, unknown>, index: number): asserts value is SessionEvent {
const event = value
if (event['type'] === 'request/header-delta') {
throw new Error(`seed event at index ${index} uses unsupported legacy request/header-delta format`)
}
const allowed = new Set(['type', 'seq', 'time', 'data', 'surfaceOp', 'sourceEventSeqs'])
if (Object.keys(event).some(key => !allowed.has(key))
|| !Object.hasOwn(event, 'type') || typeof event['type'] !== 'string'
@@ -156,9 +159,6 @@ function assertCurrentLlmShape(event: Record<string, unknown>, index: number): v
const config = typeof header === 'object' && header !== null ? (header as Record<string, unknown>)['config'] : undefined
if (!hasProviderModel(config)) throw new Error(`seed request/header at index ${index} lacks provider/model`)
}
if (event['type'] === 'request/header-delta' && record['config'] !== undefined && !hasProviderModel(record['config'])) {
throw new Error(`seed request/header-delta at index ${index} lacks provider/model`)
}
if (event['type'] === 'assistant/message' && !hasProviderModel(record['provenance'])) {
throw new Error(`seed assistant/message at index ${index} lacks provider/model provenance`)
}
@@ -172,6 +172,18 @@ function hasProviderModel(value: unknown): boolean {
&& typeof pair['model'] === 'string' && pair['model'].length > 0
}
/** Reject request-header vocabulary removed with the legacy delta codec. */
function assertSupportedRequestHeader(type: string, data: unknown, location: string): void {
if (type === 'request/header-delta') {
throw new Error(`${location} uses unsupported legacy request/header-delta format`)
}
if (type === 'request/header'
&& data !== null && typeof data === 'object' && !Array.isArray(data)
&& (data as Record<string, unknown>)['reason'] === 'fallback') {
throw new Error(`${location} uses unsupported legacy request/header reason "fallback"`)
}
}
type SessionCallback = (...args: unknown[]) => unknown
/** Resolve one listener snapshot, including Cordis's internal dispatch checks. */
@@ -243,7 +255,7 @@ export class Session {
private readonly surfaceValidator = new SurfaceManager(this.log)
/**
* Derived surface — a cached linked list of message-producing events.
* Derived surface — a cached order of message-producing event sequences.
* Lazily rebuilt from `surfaceOp` markers in the log; processes only new
* events (delta) on each access — the log is append-only, so prior events
* never change.
@@ -251,7 +263,7 @@ export class Session {
*/
private _surface: SurfaceManager | undefined
/** The surface linked list over this session's event log. */
/** The ordered surface over this session's event log. */
get surface(): SurfaceManager {
if (!this._surface) this._surface = new SurfaceManager(this.log)
return this._surface
@@ -284,6 +296,7 @@ export class Session {
throw new Error(`seed event at index ${index} is not losslessly JSON-serializable`)
}
assertSessionEventEnvelope(snapshot, index)
assertSupportedRequestHeader(snapshot.type, snapshot.data, `seed event at index ${index}`)
if (snapshot.seq !== index) {
throw new Error(`seed event at index ${index} has seq ${snapshot.seq} (expected ${index}); seed must be contiguous from 0`)
}
@@ -331,7 +344,7 @@ export class Session {
* @param type - The event type (key of {@link SessionEventMap}).
* @param data - The event payload; must be JSON-serializable.
* @param opts - Surface metadata: `surfaceOp` controls how the event enters
* the surface linked list; `sourceEventSeqs` records provenance (the seq
* the ordered surface; `sourceEventSeqs` records provenance (the seq
* numbers of events this one derives from). REQUIRED for
* {@link SurfaceEventType} events (every message-producing event must
* declare how it joins the surface, the sole source of derived history) and
@@ -368,6 +381,7 @@ export class Session {
if (dataSnapshot === undefined) {
throw new Error(`session event "${type}" carries non-JSON-serializable data`)
}
assertSupportedRequestHeader(type, dataSnapshot, `session event "${type}"`)
const surfaceMetadataSnapshot = snapshotJsonValue(surfaceMetadata)
if (surfaceMetadataSnapshot === undefined) {
throw new Error(`session event "${type}" carries non-JSON-serializable surface metadata`)
@@ -439,8 +453,8 @@ export class Session {
private derivedGeneration = 0
/**
* Derive the LLM message history by walking the session surface — the linked
* list of message-producing events maintained by `surfaceOp` markers. The
* Derive the LLM message history by walking the ordered sequences of
* message-producing events maintained by `surfaceOp` markers. The
* surface is the single source of derived history: every message-producing
* append records its `surfaceOp`, so a raw event with no marker (a chunk, a
* turn boundary) is correctly absent, and a compaction `replace` deletes the
@@ -464,11 +478,11 @@ export class Session {
this.derivedNodes = 0
this.derivedGeneration = generation
}
for (const node of nodes.slice(this.derivedNodes)) {
// Surface nodes are built from this.log — node.seq is always a valid
for (const seq of nodes.slice(this.derivedNodes)) {
// Surface sequences are built from this.log — seq is always a valid
// index by construction. The non-null assertion expresses that invariant.
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const msg = this.deriveEventMessage(this.log[node.seq]!)
const msg = this.deriveEventMessage(this.log[seq]!)
// A surface node is one of the five message-producing types, but an
// empty-content assistant/message (a max-tokens step that hosts only
// usage) derives to null and must not enter the transcript.

178
packages/core/session/src/request-header.ts
View File

@@ -1,28 +1,20 @@
/**
* Request-header reconstruction utilities over `request/header` snapshots and
* `request/header-delta` events. Writers round-trip each proposed delta and use
* a full snapshot when the encoding cannot represent the change.
* Request-header reconstruction utilities over full `request/header` session
* events. Anyone holding a session log reconstructs the {@link EpochHeader}
* any request was built under by taking the latest canonical snapshot; the
* loop uses the same equality helper to avoid logging unchanged headers.
*
* @module dsh-session/request-header
*/
import { callConfigEquals } from '@deepseek-ai/dsh-llm'
import type { LlmCallConfig, Message, ToolSchema } from '@deepseek-ai/dsh-llm'
import type { EpochHeader, SessionEvent, SystemDelta, ToolsDelta } from './types.ts'
/** The `request/header-delta` payload shape: each present field amends the folded header. */
type HeaderDelta = {
system?: SystemDelta
tools?: ToolsDelta
config?: LlmCallConfig
messagePrefix?: Message[]
}
import type { Message, ToolSchema } from '@deepseek-ai/dsh-llm'
import type { EpochHeader, SessionEvent } from './types.ts'
/**
* Normalize a header to canonical form: an empty system prompt, an empty
* tool list, and an empty session prefix become ABSENT fields, matching how
* requests are built (the request-build spreads skip empty values). Diff,
* fold, and comparison all operate on canonical headers, so "no system
* prompt" (and "no session prefix") has exactly one representation.
* Normalize a header to canonical form: an empty system prompt, an empty tool
* list, and an empty session prefix become absent fields, matching how requests
* are built. Logging, folding, and comparison use this one representation.
* @param header - the header to normalize (not mutated).
* @returns the canonical header.
*/
@@ -35,85 +27,22 @@ export function canonicalHeader(header: EpochHeader): EpochHeader {
}
}
/** Split a canonical (possibly absent) system prompt into lines; absence is zero lines. */
function systemLines(system: string | undefined): string[] {
return system === undefined ? [] : system.split('\n')
}
/** Join lines back into a canonical system value; zero lines is absence. */
function joinSystem(lines: string[]): string | undefined {
return lines.length === 0 ? undefined : lines.join('\n')
}
/**
* Compute the line-level {@link SystemDelta} between two canonical system
* prompts: trim the common prefix and (non-overlapping) common suffix, and
* carry the replacement lines between them. Deterministic and library-free;
* with nothing shared it degenerates to a full replacement.
*/
function diffSystem(prev: string | undefined, next: string | undefined): SystemDelta {
const a = systemLines(prev)
const b = systemLines(next)
let keepStart = 0
while (keepStart < a.length && keepStart < b.length && a[keepStart] === b[keepStart]) keepStart += 1
let keepEnd = 0
while (
keepEnd < a.length - keepStart &&
keepEnd < b.length - keepStart &&
a[a.length - 1 - keepEnd] === b[b.length - 1 - keepEnd]
) keepEnd += 1
return { keepStart, keepEnd, insert: b.slice(keepStart, b.length - keepEnd) }
}
/** Apply a {@link SystemDelta} to a canonical system prompt. */
function applySystem(prev: string | undefined, delta: SystemDelta): string | undefined {
const a = systemLines(prev)
return joinSystem([...a.slice(0, delta.keepStart), ...delta.insert, ...a.slice(a.length - delta.keepEnd)])
}
/** Canonical JSON equality for tool schemas — sound because schemas are
* JSON-serializable by construction and both sides come from the same
* assembly path, so key insertion order matches when the values do. */
/** Canonical JSON equality for tool schemas assembled through the same path. */
function sameSchema(a: ToolSchema, b: ToolSchema): boolean {
return JSON.stringify(a) === JSON.stringify(b)
}
/**
* Compute the name-keyed {@link ToolsDelta} between two canonical tool lists.
* A pure reordering produces an empty delta — the writer's round-trip guard
* catches that case and records a snapshot instead.
*/
function diffTools(prev: readonly ToolSchema[], next: readonly ToolSchema[]): ToolsDelta {
const prevByName = new Map(prev.map(tool => [tool.name, tool]))
const nextNames = new Set(next.map(tool => tool.name))
return {
added: next.filter(tool => !prevByName.has(tool.name)),
removed: prev.filter(tool => !nextNames.has(tool.name)).map(tool => tool.name),
changed: next.filter((tool) => {
const before = prevByName.get(tool.name)
return before !== undefined && !sameSchema(before, tool)
}),
}
}
/** Apply a {@link ToolsDelta} to a canonical tool list: drop removed, replace changed in place, append added. */
function applyTools(prev: readonly ToolSchema[], delta: ToolsDelta): ToolSchema[] {
const removed = new Set(delta.removed)
const changedByName = new Map(delta.changed.map(tool => [tool.name, tool]))
const kept = prev
.filter(tool => !removed.has(tool.name))
.map(tool => changedByName.get(tool.name) ?? tool)
return [...kept, ...delta.added]
/** Canonical JSON equality over session-prefix arrays; absence equals empty. */
function sameMessages(a: readonly Message[] | undefined, b: readonly Message[] | undefined): boolean {
return JSON.stringify(a ?? []) === JSON.stringify(b ?? [])
}
/**
* Field-wise equality over canonical headers — the cheap comparison the writer's round-trip
* guard runs (`applyHeaderDelta(prev, delta)` must equal the intended header) and the loop
* runs to skip logging an unchanged header.
*
* Field-wise equality over canonical headers. Tool schemas compare in order;
* the session prefix compares as canonical JSON.
* @param a - one canonical header.
* @param b - the other.
* @returns whether config, system, tools (in order), and the session prefix all match.
* @returns whether config, system, tools, and session prefix all match.
*/
export function headerEquals(a: EpochHeader, b: EpochHeader): boolean {
if (!callConfigEquals(a.config, b.config) || a.system !== b.system) return false
@@ -123,74 +52,19 @@ export function headerEquals(a: EpochHeader, b: EpochHeader): boolean {
return at.length === bt.length && at.every((tool, i) => sameSchema(tool, bt[i] as ToolSchema))
}
/** Canonical JSON equality over session-prefix arrays; absence equals the empty array. */
function sameMessages(a: readonly Message[] | undefined, b: readonly Message[] | undefined): boolean {
return JSON.stringify(a ?? []) === JSON.stringify(b ?? [])
}
/**
* Compute the `request/header-delta` payload between two canonical headers, or
* `undefined` when they are equal. The encoding cannot represent every change,
* including pure tool reordering, so callers must apply and compare the result
* before logging it and fall back to a full snapshot on mismatch. The session
* prefix is replaced whole; an empty array removes it.
*
* @param prev - the folded header the log currently implies.
* @param next - the header the next request will actually use.
* @returns the delta payload, or undefined when nothing changed.
*/
export function diffHeader(prev: EpochHeader, next: EpochHeader): HeaderDelta | undefined {
const delta: HeaderDelta = {}
if (prev.system !== next.system) delta.system = diffSystem(prev.system, next.system)
const prevTools = prev.tools ?? []
const nextTools = next.tools ?? []
if (JSON.stringify(prevTools) !== JSON.stringify(nextTools)) delta.tools = diffTools(prevTools, nextTools)
if (!callConfigEquals(prev.config, next.config)) delta.config = next.config
if (!sameMessages(prev.messagePrefix, next.messagePrefix)) delta.messagePrefix = next.messagePrefix ?? []
return Object.keys(delta).length > 0 ? delta : undefined
}
/**
* Apply a `request/header-delta` payload to a canonical header, producing the
* canonical header it encodes. Total for well-formed logs (the writer only
* appends round-trip-verified deltas).
* @param prev - the folded header before the delta.
* @param delta - the logged delta payload.
* @returns the canonical header after the delta.
*/
export function applyHeaderDelta(prev: EpochHeader, delta: HeaderDelta): EpochHeader {
const system = delta.system !== undefined ? applySystem(prev.system, delta.system) : prev.system
const tools = delta.tools !== undefined ? applyTools(prev.tools ?? [], delta.tools) : prev.tools
const messagePrefix = delta.messagePrefix ?? prev.messagePrefix
return canonicalHeader({
config: delta.config ?? prev.config,
...system !== undefined ? { system } : {},
...tools !== undefined ? { tools } : {},
...messagePrefix !== undefined ? { messagePrefix } : {},
})
}
/**
* Fold the header events of a log (or any prefix of one) into the {@link EpochHeader} in
* force after the last of them: each `request/header` snapshot replaces the state, each
* `request/header-delta` amends it.
*
* @param events - session events in log order (non-header events are skipped).
* @param from - a previously folded state to continue from (the live session's incremental
* cursor); omit to fold from nothing.
* @returns the folded header, or undefined when no header event exists yet.
* Fold the header events of a log (or any prefix) into the
* {@link EpochHeader} in force after the last snapshot. Non-header events are
* skipped. This is the pure offline reconstruction path; the live session
* tracks the same fold incrementally.
* @param events - session events in log order.
* @param from - a previously folded state to continue from.
* @returns the latest canonical header, or undefined when none exists yet.
*/
export function foldRequestHeader(events: readonly SessionEvent[], from?: EpochHeader): EpochHeader | undefined {
let state: EpochHeader | undefined = from
let state = from
for (const event of events) {
if (event.type === 'request/header') {
state = canonicalHeader(event.data.header)
} else if (event.type === 'request/header-delta') {
if (state === undefined) {
throw new Error(`request/header-delta at seq ${event.seq} before any request/header snapshot: corrupt log`)
}
state = applyHeaderDelta(state, event.data)
}
if (event.type === 'request/header') state = canonicalHeader(event.data.header)
}
return state
}

163
packages/core/session/src/surface.ts
View File

@@ -1,19 +1,13 @@
/**
* Surface layer on top of the session event log: a derived, cached linked list
* of events that produce LLM messages. Rebuilt deterministically from
* `surfaceOp` markers in the log — the log is the source of truth; the surface
* is a view.
* Surface layer on top of the session event log: an ordered view of events
* that produce LLM messages. The append-only log remains the source of truth.
*
* @module @deepseek-ai/dsh-session/surface
*/
import type { SessionEvent, SurfaceEvent, SurfaceEventType, SurfaceOp } from './types.ts'
/**
* The set of event type strings that are eligible for the surface linked list.
* Mirrors the {@link SurfaceEventType} union; kept as a runtime set so the
* type guard can check membership without a chain of string comparisons.
*/
/** Runtime counterpart of the message-producing event union. */
const SURFACE_EVENT_TYPES = new Set<string>([
'user/message',
'assistant/message',
@@ -23,39 +17,22 @@ const SURFACE_EVENT_TYPES = new Set<string>([
])
/**
* Check only whether a type may enter the message surface; it does not require `surfaceOp`. This
* detects eligible seed/load events missing their mandatory marker. Use {@link isSurfaceEvent} to
* narrow a fully formed event whose marker is present.
* @param type - the event type string to test.
* @returns true when the type is one of the five message-producing types.
* Whether an event type can join the model-visible surface.
* @param type - event type to test.
* @returns true for one of the five message-producing event types.
*/
export function isSurfaceEligibleType(type: string): boolean {
return SURFACE_EVENT_TYPES.has(type)
}
/**
* Narrow a {@link SessionEvent} to {@link SurfaceEvent}: checks that the
* event's `type` is surface-eligible AND that `surfaceOp` is present.
* The narrowed type has mandatory {@link SurfaceOp}.
* @param event - the event to narrow.
* @returns true when the event is surface-eligible and carries its `surfaceOp` marker.
* Narrow an event to a surface-eligible event carrying its required marker.
* @param event - event to test.
* @returns true when both the type and marker identify a surface event.
*/
export function isSurfaceEvent(event: SessionEvent): event is SurfaceEvent {
if (!SURFACE_EVENT_TYPES.has(event.type)) return false
// surfaceOp is optional on SessionEvent (even for surface-eligible types)
// but mandatory on SurfaceEvent — this check is the narrowing gate.
if ((event as SessionEvent<SurfaceEventType>).surfaceOp === undefined) return false
return true
}
/** One node in the surface linked list. */
export interface SurfaceNode {
/** The event seq of this surface node. */
seq: number
/** The previous surface node's seq, or null if this is the head. */
prev: number | null
/** The next surface node's seq, or null if this is the tail. */
next: number | null
return (event as SessionEvent<SurfaceEventType>).surfaceOp !== undefined
}
/** One replacement operation observed while folding a session surface. */
@@ -66,22 +43,21 @@ export interface SurfaceFoldReplacement {
start: number
/** Declared inclusive end seq of the replaced surface range. */
end: number
/** Actual surface nodes removed by the operation, in surface order. */
/** Actual surface entries removed by the operation, in surface order. */
shadowedSeqs: number[]
}
/** Complete result of replaying the surface operations in a session log. */
export interface SurfaceFoldResult {
/** Current surface nodes in linked-list order. */
nodes: SurfaceNode[]
/** Current surface event sequences in model-visible order. */
nodes: number[]
/** Replacement operations in event order. */
replacements: SurfaceFoldReplacement[]
}
/** Mutable state shared by the incremental manager and the full-log fold. */
/** Mutable state shared by complete and incremental folds. */
interface SurfaceFoldState {
nodes: SurfaceNode[]
nodeBySeq: Map<number, SurfaceNode>
nodes: number[]
replaceGeneration: number
}
@@ -98,12 +74,8 @@ type SurfacePlan =
| SurfaceReplacePlan
/** Create an empty surface fold state. */
function createFoldState(replaceGeneration = 0): SurfaceFoldState {
return {
nodes: [],
nodeBySeq: new Map(),
replaceGeneration,
}
function createFoldState(): SurfaceFoldState {
return { nodes: [], replaceGeneration: 0 }
}
/** Whether a runtime value is a non-negative safe event sequence. */
@@ -189,23 +161,21 @@ function replacementRange(
state: SurfaceFoldState,
op: Extract<SurfaceOp, { op: 'replace' }>,
): Pick<SurfaceReplacePlan, 'startIdx' | 'endIdx' | 'shadowedSeqs'> {
const startNode = state.nodeBySeq.get(op.start)
if (!startNode) {
const startIdx = state.nodes.indexOf(op.start)
if (startIdx === -1) {
throw new Error(`surface replace: start seq ${op.start} not found in surface`)
}
const endNode = state.nodeBySeq.get(op.end)
if (!endNode) {
const endIdx = state.nodes.indexOf(op.end)
if (endIdx === -1) {
throw new Error(`surface replace: end seq ${op.end} not found in surface`)
}
const startIdx = state.nodes.indexOf(startNode)
const endIdx = state.nodes.indexOf(endNode)
if (startIdx > endIdx) {
throw new Error(`surface replace: start seq ${op.start} (index ${startIdx}) is after end seq ${op.end} (index ${endIdx})`)
}
return {
startIdx,
endIdx,
shadowedSeqs: state.nodes.slice(startIdx, endIdx + 1).map(node => node.seq),
shadowedSeqs: state.nodes.slice(startIdx, endIdx + 1),
}
}
@@ -235,27 +205,6 @@ function planSurfaceEvent(
}
}
/** Apply one already-validated positional replacement. */
function replaceSurface(state: SurfaceFoldState, plan: SurfaceReplacePlan): void {
const { startIdx, endIdx } = plan
const removed = state.nodes.splice(startIdx, endIdx - startIdx + 1)
for (const node of removed) state.nodeBySeq.delete(node.seq)
const prevNode = startIdx > 0 ? state.nodes[startIdx - 1] : undefined
const nextNode = startIdx < state.nodes.length ? state.nodes[startIdx] : undefined
const newNode: SurfaceNode = {
seq: plan.seq,
prev: prevNode?.seq ?? null,
next: nextNode?.seq ?? null,
}
if (prevNode) prevNode.next = plan.seq
if (nextNode) nextNode.prev = plan.seq
state.nodes.splice(startIdx, 0, newNode)
state.nodeBySeq.set(plan.seq, newNode)
state.replaceGeneration += 1
}
/** Apply one event and return replacement metadata only when one occurred. */
function applySurfaceEvent(
state: SurfaceFoldState,
@@ -264,13 +213,10 @@ function applySurfaceEvent(
): SurfaceFoldReplacement | undefined {
const plan = planSurfaceEvent(state, event, expectedSeq)
if (plan?.kind === 'append') {
const tail = state.nodes.at(-1)
const node: SurfaceNode = { seq: plan.seq, prev: tail?.seq ?? null, next: null }
if (tail) tail.next = plan.seq
state.nodes.push(node)
state.nodeBySeq.set(plan.seq, node)
state.nodes.push(plan.seq)
} else if (plan?.kind === 'replace') {
replaceSurface(state, plan)
state.nodes.splice(plan.startIdx, plan.endIdx - plan.startIdx + 1, plan.seq)
state.replaceGeneration += 1
}
if (plan?.kind !== 'replace') return
return {
@@ -283,16 +229,9 @@ function applySurfaceEvent(
/**
* Replay a complete session log through the canonical surface fold.
*
* The returned arrays and nodes are detached snapshots. The incremental
* {@link SurfaceManager} uses the same transition functions, so query read
* models cannot disagree with `deriveMessages()` about replacement ranges.
* @param events - session events in contiguous seq order.
* @returns the current surface and every positional replacement.
* @throws when any event violates the unified surface contract: metadata must
* be well shaped and type-eligible, event seqs must be contiguous, provenance
* must name unique earlier events, and a positional replacement must name and
* cite its complete range.
* @returns detached current sequences and replacement history.
* @throws when an event violates surface metadata, provenance, or range rules.
*/
export function foldSurface(events: readonly SessionEvent[]): SurfaceFoldResult {
const state = createFoldState()
@@ -301,68 +240,44 @@ export function foldSurface(events: readonly SessionEvent[]): SurfaceFoldResult
const replacement = applySurfaceEvent(state, event, index)
if (replacement !== undefined) replacements.push(replacement)
}
return {
nodes: state.nodes.map(node => ({ ...node })),
replacements,
}
return { nodes: [...state.nodes], replacements }
}
/**
* Maintains a cached linked list of surface nodes and validates each candidate
* before it enters the event log. Because the log is append-only, it processes
* only committed deltas and plans the candidate without mutation rather than
* rescanning the whole log.
*/
/** Incremental ordered surface view and append-boundary validator. */
export class SurfaceManager {
/** Incremental state shared with the complete surface fold. */
/** Shared transition state; replacement history is not retained. */
private _state = createFoldState()
/** The last processed seq. -1 folds the seeded log on first access. */
/** Last processed seq; -1 folds a seeded log on first access. */
private _lastProcessedSeq = -1
constructor(private log: readonly SessionEvent[]) {}
/**
* Validate one candidate as the next log event without applying it. The
* committed log is folded first, then the candidate's complete surface and
* provenance transition is planned atomically; a failure leaves the current
* surface unchanged.
* @param event - candidate event that has not entered `log` yet.
* Validate the next candidate without mutating the committed surface.
* @param event - candidate event that has not entered the log yet.
*/
validateNext(event: SessionEvent): void {
if (this._lastProcessedSeq < this.log.length - 1) this._processDelta()
planSurfaceEvent(this._state, event, this.log.length)
}
/**
* The surface's rewrite generation, bumped by every folded `replace` op.
* A replace is the ONE operation that rewrites the
* surface non-monotonically, so an incremental consumer of {@link nodes}
* (the session's derived-message cache) compares this between visits — an
* unchanged generation guarantees every node it has not seen is a pure tail
* append; a changed one means its view must rebuild. Monotonic: it never
* moves backwards, so comparisons cannot be fooled by a re-fold.
*/
/** Monotonic count of folded positional replacements. */
get replaceGeneration(): number {
if (this._lastProcessedSeq < this.log.length - 1) this._processDelta()
return this._state.replaceGeneration
}
/** The surface nodes in linked-list order (head to tail). */
get nodes(): readonly SurfaceNode[] {
/** Surface event sequences in model-visible order. */
get nodes(): readonly number[] {
if (this._lastProcessedSeq < this.log.length - 1) this._processDelta()
return this._state.nodes
}
/**
* Process events from `_lastProcessedSeq + 1` through the end of the log,
* folding new surface markers into the existing linked list.
*/
/** Fold events appended since the previous access. */
private _processDelta(): void {
for (let i = this._lastProcessedSeq + 1; i < this.log.length; i++) {
// Index is bounded by i < this.log.length — never undefined.
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const event = this.log[i]!
applySurfaceEvent(this._state, event, i)
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- bounded by the loop condition
applySurfaceEvent(this._state, this.log[i]!, i)
this._lastProcessedSeq = i
}
}

61
packages/core/session/src/types.ts
View File

@@ -143,7 +143,7 @@ export interface TodoItem {
/**
* Logged request state outside derived history: call config, system prompt,
* tools, and session prefix. Header snapshots and deltas reconstruct it;
* tools, and prefix. The latest full `request/header` snapshot reconstructs it;
* canonical empty optional fields are absent.
*/
export interface EpochHeader {
@@ -167,43 +167,9 @@ export interface EpochHeader {
* Why a `request/header` snapshot was appended: `'initial'` — the log's first
* header (a new conversation); `'resume'` — a loop instance's first request
* over a log that already has header events (process restart, fork seed);
* `'fallback'` — a mid-run change the delta encoding could not round-trip
* (e.g. a pure tool reordering), recorded whole instead.
* `'change'` — a later request used a different header.
*/
export type RequestHeaderReason = 'initial' | 'resume' | 'fallback'
/**
* Line-level edit of the system prompt: keep the first `keepStart` and last
* `keepEnd` lines of the previous text, with `insert` replacing everything
* between. Computed as a common-prefix/common-suffix trim — deterministic,
* library-free, degenerating to a full replacement when nothing is shared.
* Absence is encoded as zero lines (the canonical form has no empty-string
* system), so a transition to or from "no system prompt" round-trips.
*/
export interface SystemDelta {
/** Lines kept from the start of the previous system prompt. */
keepStart: number
/** Lines kept from the end of the previous system prompt. */
keepEnd: number
/** Lines replacing everything between the kept edges. */
insert: string[]
}
/**
* Tool-set edit keyed by tool name (names are unique — the registry rejects
* duplicates): `removed` names drop, `changed` schemas replace their
* predecessor in place, `added` schemas append at the end. A change this
* encoding cannot express (a pure reordering) fails the writer's round-trip
* guard and is recorded as a `'fallback'` snapshot instead.
*/
export interface ToolsDelta {
/** Schemas appended to the end of the tool list. */
added: ToolSchema[]
/** Names of schemas dropped from the tool list. */
removed: string[]
/** Schemas replacing the same-named predecessor in place. */
changed: ToolSchema[]
}
export type RequestHeaderReason = 'initial' | 'resume' | 'change'
/**
* The merge-extensible, append-only source of truth for an agent interaction.
@@ -276,22 +242,13 @@ export interface SessionEventMap {
'tool/result': { turn: number; step: number; callId: CallId; content: ContentBlock[]; isError: boolean; error?: { name: string; code: string }; meta?: unknown }
/** Steering content injected between steps of a running turn. */
'steering/message': { turn: number; content: ContentBlock[]; source: MessageSource }
/**
* Whole-list snapshot; the latest write wins on replay. It is log-only UI
* state and never enters derived model history.
*/
/** Whole-list snapshot; latest write wins on replay. Log-only UI state; never derived history. */
'todo/write': { todos: TodoItem[] }
/**
* Full {@link EpochHeader} for the next request, appended inside its step
* before dispatch. It is log-only and anchors subsequent deltas.
* Full header for the next request, appended inside its step before dispatch.
* It is log-only; the latest snapshot reconstructs the request header.
*/
'request/header': { header: EpochHeader; reason: RequestHeaderReason }
/**
* Log-only amendment to the folded {@link EpochHeader}. System and tools use
* their delta codecs; config and prefix replace whole, with an empty prefix
* encoding removal. Writers verify round-trip equality or log a fallback snapshot.
*/
'request/header-delta': { system?: SystemDelta; tools?: ToolsDelta; config?: LlmCallConfig; messagePrefix?: Message[] }
}
/** The appendable event-type keys of {@link SessionEventMap}, plugin-merged extensions included. */
@@ -299,7 +256,7 @@ export type SessionEventType = keyof SessionEventMap
/**
* The subset of {@link SessionEventType} values whose events produce LLM
* messages and are eligible to appear on the surface linked list. Only these
* messages and are eligible to appear on the ordered surface. Only these
* event types may carry {@link SurfaceOp} and {@link SessionEvent.sourceEventSeqs}.
*/
export type SurfaceEventType =
@@ -310,7 +267,7 @@ export type SurfaceEventType =
| 'steering/message'
/**
* A {@link SessionEvent} that is **on** the surface linked list — its
* A {@link SessionEvent} that is **on** the ordered surface — its
* `surfaceOp` is guaranteed present (mandatory), narrowed from a
* surface-eligible {@link SessionEvent} by checking both `type` and
* `surfaceOp` at runtime.
@@ -321,7 +278,7 @@ export type SurfaceEventType =
export type SurfaceEvent = SessionEvent<SurfaceEventType> & { surfaceOp: SurfaceOp }
/**
* How a session event entered the surface linked list. Only valid on
* How a session event entered the ordered surface. Only valid on
* {@link SurfaceEventType} events.
*
* - `'append'`: added to the tail — normal path for user/assistant/tool/context

2
packages/core/session/tests/derived-cache.spec.ts
View File

@@ -40,7 +40,7 @@ describe('derived-message cache', () => {
const nodes = session.surface.nodes
session.append('context/message', {
content: [{ type: 'text', text: 'summary' }], source: { kind: 'plugin', plugin: 'compact' },
}, { surfaceOp: { op: 'replace', start: nodes[0]!.seq, end: nodes[1]!.seq }, sourceEventSeqs: [nodes[0]!.seq, nodes[1]!.seq] })
}, { surfaceOp: { op: 'replace', start: nodes[0]!, end: nodes[1]! }, sourceEventSeqs: [nodes[0]!, nodes[1]!] })
expect(session.deriveMessages()).toHaveLength(1)
expect(session.deriveMessages()).toEqual(scratch(session))

213
packages/core/session/tests/request-header.spec.ts
View File

@@ -1,14 +1,7 @@
/**
* Request-header utility tests: canonical form, the system line-diff
* (prefix/suffix trim), the name-keyed tools delta, config replacement, the
* round-trip contract (including the reorder case the encoding cannot
* express), and the log fold. These pin the reconstruction algebra: for every
* logged delta, apply(prev, delta) === next, and folding a log prefix yields
* the header its next request was built under.
*/
/** Request-header canonicalization, equality, snapshot folding, and format rejection. */
import { describe, expect, it } from 'vitest'
import { Session, SessionId, applyHeaderDelta, canonicalHeader, diffHeader, foldRequestHeader, headerEquals } from '@deepseek-ai/dsh-session'
import { Session, SessionId, canonicalHeader, foldRequestHeader, headerEquals } from '@deepseek-ai/dsh-session'
import type { EpochHeader, SessionEvent } from '@deepseek-ai/dsh-session'
import type { Message, ToolSchema } from '@deepseek-ai/dsh-llm'
@@ -22,165 +15,77 @@ function msg(text: string): Message {
return { role: 'user', content: [{ type: 'text', text }] }
}
/** Round-trip helper: diff must reproduce `next` from `prev` exactly. */
function roundTrip(prev: EpochHeader, next: EpochHeader): ReturnType<typeof diffHeader> {
const delta = diffHeader(prev, next)
if (delta !== undefined) {
expect(applyHeaderDelta(prev, delta)).toEqual(canonicalHeader(next))
}
return delta
}
describe('canonicalHeader', () => {
it('normalizes empty system and empty tools to absent fields', () => {
expect(canonicalHeader({ config: CONFIG, system: '', tools: [] })).toEqual({ config: CONFIG })
const full = canonicalHeader({ config: CONFIG, system: 's', tools: [tool('a')] })
expect(full.system).toBe('s')
expect(full.tools).toHaveLength(1)
it('normalizes empty optional fields to absence and preserves populated fields', () => {
expect(canonicalHeader({ config: CONFIG, system: '', tools: [], messagePrefix: [] })).toEqual({ config: CONFIG })
const full = canonicalHeader({ config: CONFIG, system: 's', tools: [tool('a')], messagePrefix: [msg('p')] })
expect(full).toEqual({ config: CONFIG, system: 's', tools: [tool('a')], messagePrefix: [msg('p')] })
})
})
describe('diffHeader / applyHeaderDelta', () => {
it('returns undefined for equal headers', () => {
const header = canonicalHeader({ config: CONFIG, system: 'a\nb', tools: [tool('t')] })
expect(diffHeader(header, header)).toBeUndefined()
describe('headerEquals', () => {
const base = canonicalHeader({ config: CONFIG, system: 's', tools: [tool('a')], messagePrefix: [msg('p')] })
it('compares every canonical field and preserves tool order', () => {
expect(headerEquals(base, structuredClone(base))).toBe(true)
expect(headerEquals(base, { ...base, config: { provider: 'mock', model: 'other' } })).toBe(false)
expect(headerEquals(base, { ...base, system: 'other' })).toBe(false)
expect(headerEquals(base, { ...base, messagePrefix: [msg('other')] })).toBe(false)
expect(headerEquals(base, { ...base, tools: [] })).toBe(false)
expect(headerEquals(base, { ...base, tools: [tool('a', 'changed')] })).toBe(false)
expect(headerEquals({ config: CONFIG, tools: [tool('a'), tool('b')] }, { config: CONFIG, tools: [tool('b'), tool('a')] })).toBe(false)
})
it('encodes a mid-prompt line change as a prefix/suffix trim', () => {
const prev = canonicalHeader({ config: CONFIG, system: 'keep1\nold\nkeep2\nkeep3' })
const next = canonicalHeader({ config: CONFIG, system: 'keep1\nnew A\nnew B\nkeep2\nkeep3' })
const delta = roundTrip(prev, next)
expect(delta?.system).toEqual({ keepStart: 1, keepEnd: 2, insert: ['new A', 'new B'] })
expect(delta?.tools).toBeUndefined()
expect(delta?.config).toBeUndefined()
})
it('degenerates to a full replacement when nothing is shared, and round-trips absence transitions', () => {
const none = canonicalHeader({ config: CONFIG })
const some = canonicalHeader({ config: CONFIG, system: 'x\ny' })
const gained = roundTrip(none, some)
expect(gained?.system).toEqual({ keepStart: 0, keepEnd: 0, insert: ['x', 'y'] })
const lost = roundTrip(some, none)
expect(lost?.system).toEqual({ keepStart: 0, keepEnd: 0, insert: [] })
})
it('does not double-count overlapping prefix and suffix (repeated lines)', () => {
const prev = canonicalHeader({ config: CONFIG, system: 'a\na' })
const next = canonicalHeader({ config: CONFIG, system: 'a\na\na' })
roundTrip(prev, next)
})
it('encodes tool addition, removal, and in-place schema change by name', () => {
const prev = canonicalHeader({ config: CONFIG, tools: [tool('keep'), tool('drop'), tool('edit', 'before')] })
const next = canonicalHeader({ config: CONFIG, tools: [tool('keep'), tool('edit', 'after'), tool('new')] })
const delta = roundTrip(prev, next)
expect(delta?.tools?.added.map(t => t.name)).toEqual(['new'])
expect(delta?.tools?.removed).toEqual(['drop'])
expect(delta?.tools?.changed.map(t => t.name)).toEqual(['edit'])
})
it('round-trips a tool set gained from a tool-less header and lost back to one', () => {
const none = canonicalHeader({ config: CONFIG })
const some = canonicalHeader({ config: CONFIG, tools: [tool('t')] })
const gained = roundTrip(none, some)
expect(gained?.tools?.added.map(t => t.name)).toEqual(['t'])
const lost = roundTrip(some, none)
expect(lost?.tools?.removed).toEqual(['t'])
})
it('cannot express a pure reordering — the writer detects it via the round-trip check', () => {
const prev = canonicalHeader({ config: CONFIG, tools: [tool('a'), tool('b')] })
const next = canonicalHeader({ config: CONFIG, tools: [tool('b'), tool('a')] })
const delta = diffHeader(prev, next)
// A delta IS produced (the lists differ)…
expect(delta).toBeDefined()
// …but applying it cannot reproduce the new order — exactly the case the
// writer's guard turns into a 'fallback' snapshot.
expect(applyHeaderDelta(prev, delta!)).not.toEqual(next)
})
it('replaces the config whole and leaves untouched parts alone', () => {
const prev = canonicalHeader({ config: { provider: 'mock', model: 'm' }, system: 's', tools: [tool('t')] })
const next = canonicalHeader({ config: { provider: 'mock', model: 'm2', temperature: 0.1 }, system: 's', tools: [tool('t')] })
const delta = roundTrip(prev, next)
expect(delta).toEqual({ config: { provider: 'mock', model: 'm2', temperature: 0.1 } })
})
})
describe('the session prefix (messagePrefix)', () => {
it('canonicalHeader normalizes an empty prefix to an absent field', () => {
expect(canonicalHeader({ config: CONFIG, messagePrefix: [] })).toEqual({ config: CONFIG })
const full = canonicalHeader({ config: CONFIG, messagePrefix: [msg('p')] })
expect(full.messagePrefix).toEqual([msg('p')])
})
it('headerEquals treats absence and empty as one representation, content differences as unequal', () => {
expect(headerEquals(canonicalHeader({ config: CONFIG }), { config: CONFIG, messagePrefix: [] })).toBe(true)
expect(headerEquals({ config: CONFIG, messagePrefix: [msg('a')] }, { config: CONFIG, messagePrefix: [msg('b')] })).toBe(false)
expect(headerEquals({ config: CONFIG, messagePrefix: [msg('a')] }, { config: CONFIG })).toBe(false)
})
it('replaces a changed prefix whole and leaves untouched parts alone', () => {
const prev = canonicalHeader({ config: CONFIG, system: 'keep', messagePrefix: [msg('old')] })
const next = canonicalHeader({ config: CONFIG, system: 'keep', messagePrefix: [msg('new'), msg('more')] })
const delta = roundTrip(prev, next)
expect(delta).toEqual({ messagePrefix: [msg('new'), msg('more')] })
})
it('round-trips a prefix gained from a bare header and lost back to one (empty array encodes absence)', () => {
const none = canonicalHeader({ config: CONFIG })
const some = canonicalHeader({ config: CONFIG, messagePrefix: [msg('p')] })
const gained = roundTrip(none, some)
expect(gained).toEqual({ messagePrefix: [msg('p')] })
const lost = roundTrip(some, none)
expect(lost).toEqual({ messagePrefix: [] })
})
it('folds prefix deltas over the log like any other header amendment', () => {
const session = new Session(SessionId('fold-prefix'))
session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
const first = canonicalHeader({ config: CONFIG, messagePrefix: [msg('catalog v1')] })
session.append('request/header', { header: first, reason: 'initial' })
const second = canonicalHeader({ config: CONFIG, messagePrefix: [msg('catalog v2')] })
session.append('request/header-delta', diffHeader(first, second)!)
expect(foldRequestHeader(session.events)).toEqual(second)
session.append('request/header-delta', diffHeader(second, canonicalHeader({ config: CONFIG }))!)
expect(foldRequestHeader(session.events)).toEqual({ config: CONFIG })
it('treats absent and empty prefix/tool arrays as equivalent canonical absence', () => {
expect(headerEquals({ config: CONFIG }, { config: CONFIG, tools: [], messagePrefix: [] })).toBe(true)
})
})
describe('foldRequestHeader', () => {
function headerEvents(session: Session): readonly SessionEvent[] {
return session.events
}
it('returns undefined on a log with no header events', () => {
const session = new Session(SessionId('fold-none'))
session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
expect(foldRequestHeader(headerEvents(session))).toBeUndefined()
it('returns the supplied baseline when no snapshot follows', () => {
const from: EpochHeader = { config: CONFIG, system: 'baseline' }
const unrelated: SessionEvent[] = [
{ type: 'turn/start', seq: 0, time: 1, data: { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } } },
]
expect(foldRequestHeader(unrelated)).toBeUndefined()
expect(foldRequestHeader(unrelated, from)).toBe(from)
})
it('folds snapshot then deltas into the header in force, skipping unrelated events', () => {
it('takes the latest full snapshot and skips unrelated events', () => {
const session = new Session(SessionId('fold'))
session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
const first = canonicalHeader({ config: { provider: 'mock', model: 'm' }, system: 'a\nb', tools: [tool('t')] })
session.append('request/header', { header: first, reason: 'initial' })
session.append('request/header', { header: { config: CONFIG, system: 'first' }, reason: 'initial' })
session.append('user/message', { content: [{ type: 'text', text: 'hi' }], source: { kind: 'user' } }, { surfaceOp: 'append' })
const second = canonicalHeader({ config: { provider: 'mock', model: 'm' }, system: 'a\nc', tools: [tool('t')] })
session.append('request/header-delta', diffHeader(first, second)!)
expect(foldRequestHeader(headerEvents(session))).toEqual(second)
// A later snapshot replaces the state wholesale (the 'resume'/'fallback' anchor).
const third = canonicalHeader({ config: { provider: 'mock', model: 'other' } })
session.append('request/header', { header: third, reason: 'resume' })
expect(foldRequestHeader(headerEvents(session))).toEqual(third)
})
it('throws on a delta before any snapshot (corrupt log)', () => {
const session = new Session(SessionId('fold-corrupt'))
session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
session.append('request/header-delta', { config: { provider: 'mock', model: 'x' } })
expect(() => foldRequestHeader(headerEvents(session))).toThrow(/before any request\/header snapshot/)
session.append('request/header', { header: { config: { provider: 'mock', model: 'other' }, tools: [] }, reason: 'change' })
expect(foldRequestHeader(session.events)).toEqual({ config: { provider: 'mock', model: 'other' } })
})
})
describe('legacy request-header format', () => {
it('rejects request/header-delta in seeds and untyped appends', () => {
const legacy = [{
type: 'request/header-delta', seq: 0, time: 1, data: { config: CONFIG },
}] as unknown as SessionEvent[]
expect(() => new Session(SessionId('legacy'), legacy)).toThrow(/unsupported legacy request\/header-delta/)
const session = new Session(SessionId('legacy-append-delta'))
const appendLegacy = session.append.bind(session) as (type: string, data: unknown) => SessionEvent
expect(() => appendLegacy('request/header-delta', { config: CONFIG }))
.toThrow(/unsupported legacy request\/header-delta/)
expect(session.events).toHaveLength(0)
})
it('rejects the removed fallback reason in seeds and untyped appends', () => {
const legacy = [{
type: 'request/header', seq: 0, time: 1, data: { header: { config: CONFIG }, reason: 'fallback' },
}] as unknown as SessionEvent[]
expect(() => new Session(SessionId('legacy-seed-reason'), legacy))
.toThrow('unsupported legacy request/header reason "fallback"')
const session = new Session(SessionId('legacy-append-reason'))
const appendLegacy = session.append.bind(session) as (type: string, data: unknown) => SessionEvent
expect(() => appendLegacy('request/header', { header: { config: CONFIG }, reason: 'fallback' }))
.toThrow('unsupported legacy request/header reason "fallback"')
expect(session.events).toHaveLength(0)
})
})

11
packages/core/session/tests/session.spec.ts
View File

@@ -101,13 +101,6 @@ describe('Session', () => {
expect(() => new Session(SessionId('old-header'), [requestHeader]))
.toThrow('seed request/header at index 0 lacks provider/model')
const requestDelta = {
type: 'request/header-delta', seq: 0, time: 1,
data: { config: { model: 'old-model' } },
} as unknown as SessionEvent
expect(() => new Session(SessionId('old-delta'), [requestDelta]))
.toThrow('seed request/header-delta at index 0 lacks provider/model')
const assistantMessage = {
type: 'assistant/message', seq: 0, time: 1,
data: { turn: 1, step: 1, content: [{ type: 'text', text: 'old' }] },
@@ -1244,8 +1237,8 @@ describe('todo/write event', () => {
session.append('todo/write', { todos: [{ content: 'a task', status: 'pending' }] })
// The todo event must not add a message to the derived history…
expect(session.deriveMessages()).toHaveLength(before)
// …and must not appear on the surface linked list.
expect(session.surface.nodes.some(node => node.seq === session.seq - 1)).toBe(false)
// …and must not appear on the ordered surface.
expect(session.surface.nodes).not.toContain(session.seq - 1)
})
it('round-trips through a seeded replay identically (durable, no surfaceOp needed)', () => {

57
packages/core/session/tests/surface.spec.ts
View File

@@ -95,7 +95,7 @@ describe('foldSurface provenance', () => {
})
describe('SurfaceManager', () => {
it('shares exact nodes and nested replacement ranges with foldSurface', () => {
it('shares ordered entries and nested replacement ranges with foldSurface', () => {
const s = new Session(SessionId('shared-fold'))
s.append('user/message', { content: [{ type: 'text', text: 'a' }], source: { kind: 'user' } }, { surfaceOp: 'append' })
s.append('user/message', { content: [{ type: 'text', text: 'b' }], source: { kind: 'user' } }, { surfaceOp: 'append' })
@@ -108,9 +108,10 @@ describe('SurfaceManager', () => {
{ seq: 2, start: 0, end: 0, shadowedSeqs: [0] },
{ seq: 3, start: 2, end: 1, shadowedSeqs: [2, 1] },
])
folded.nodes[0]!.next = 99
folded.nodes[0] = 99
folded.replacements[0]!.shadowedSeqs.push(99)
expect(s.surface.nodes).toEqual([{ seq: 3, prev: null, next: null }])
expect(s.surface.nodes).toEqual([3])
expect(foldSurface(s.events).nodes).toEqual([3])
expect(foldSurface(s.events).replacements[0]!.shadowedSeqs).toEqual([0])
})
@@ -119,7 +120,7 @@ describe('SurfaceManager', () => {
s.append('user/message', { content: [{ type: 'text', text: 'a' }], source: { kind: 'user' } }, { surfaceOp: 'append' })
s.append('assistant/message', { provenance: { provider: 'mock', model: 'mock' }, turn: 1, step: 1, content: [{ type: 'text', text: 'b' }] }, { surfaceOp: { op: 'replace', start: 0, end: 0 }, sourceEventSeqs: [0] })
expect(s.surface.nodes).toEqual([{ seq: 1, prev: null, next: null }])
expect(s.surface.nodes).toEqual([1])
const manager = s.surface as unknown as { _state: object }
expect(Object.hasOwn(manager._state, 'replacements')).toBe(false)
expect(foldSurface(s.events).replacements).toEqual([
@@ -150,7 +151,7 @@ describe('SurfaceManager', () => {
expect(s.events).toHaveLength(1)
s.append('user/message', { content: [{ type: 'text', text: 'b' }], source: { kind: 'user' } }, { surfaceOp: 'append' })
expect(s.surface.nodes.map(node => node.seq)).toEqual([0, 1])
expect(s.surface.nodes).toEqual([0, 1])
})
it('foldSurface rejects a surface-eligible event without its mandatory marker', () => {
@@ -178,18 +179,12 @@ describe('SurfaceManager', () => {
.toThrow(/not surface-eligible and cannot carry surfaceOp/)
})
it('rebuilds a linked list from surfaceOp: append markers', () => {
it('folds an ordered sequence list from surfaceOp: append markers', () => {
const s = surfaceSession()
const nodes = s.surface.nodes
// Only the user/message and assistant/message carry surfaceOp: 'append'.
// The turn boundaries do not have surface markers.
expect(nodes.length).toBe(2)
expect(nodes[0]!.seq).toBe(1) // user/message (turn/start is seq 0)
expect(nodes[0]!.prev).toBeNull()
expect(nodes[0]!.next).toBe(2) // assistant/message (seq 2)
expect(nodes[1]!.seq).toBe(2)
expect(nodes[1]!.prev).toBe(1)
expect(nodes[1]!.next).toBeNull()
expect(nodes).toEqual([1, 2])
})
it('empty surface yields empty nodes', () => {
@@ -210,9 +205,7 @@ describe('SurfaceManager', () => {
// Append another surface node
s.append('tool/result', { turn: 1, step: 1, callId: CallId('c1'), content: [{ type: 'text', text: 'ok' }], isError: false }, { surfaceOp: 'append' })
expect(s.surface.nodes.length).toBe(3)
expect(s.surface.nodes[2]!.seq).toBe(4) // seq 4: after turn/end at seq 3
expect(s.surface.nodes[2]!.prev).toBe(2)
expect(s.surface.nodes[1]!.next).toBe(4)
expect(s.surface.nodes[2]!).toBe(4) // seq 4: after turn/end at seq 3
})
it('replays identically from a seeded log with surface markers', () => {
@@ -220,21 +213,17 @@ describe('SurfaceManager', () => {
original.append('tool/result', { turn: 1, step: 1, callId: CallId('c1'), content: [{ type: 'text', text: 'ok' }], isError: false }, { surfaceOp: 'append' })
const replayed = new Session(SessionId('replay'), [...original.events])
// Surface rebuilds from the seeded log's markers.
expect(replayed.surface.nodes.map(n => n.seq)).toEqual([1, 2, 4])
expect(replayed.surface.nodes).toEqual([1, 2, 4])
expect(replayed.deriveMessages()).toEqual(original.deriveMessages())
})
it('rebuild with replace operation splices out shadowed nodes', () => {
const s = surfaceSession()
// Replace surface seqs 1 (user) and 2 (assistant) with the summary.
s.append('assistant/message',
{ provenance: { provider: 'mock', model: 'mock' }, turn: 2, step: 1, content: [{ type: 'text', text: 'summary' }] },
{ surfaceOp: { op: 'replace', start: 1, end: 2 }, sourceEventSeqs: [1, 2] },
)
expect(s.surface.nodes.length).toBe(1)
expect(s.surface.nodes[0]!.seq).toBe(4) // seq of the compaction marker
expect(s.surface.nodes[0]!.prev).toBeNull()
expect(s.surface.nodes[0]!.next).toBeNull()
expect(s.surface.nodes).toEqual([4])
})
it('replace with both ends at real nodes splices only the range', () => {
@@ -247,12 +236,7 @@ describe('SurfaceManager', () => {
{ provenance: { provider: 'mock', model: 'mock' }, turn: 1, step: 1, content: [{ type: 'text', text: 'summary' }] },
{ surfaceOp: { op: 'replace', start: 0, end: 1 }, sourceEventSeqs: [0, 1] },
) // seq 3
expect(s.surface.nodes.map(n => n.seq)).toEqual([3, 2])
// Links: 3 ↔ 2
expect(s.surface.nodes[0]!.prev).toBeNull()
expect(s.surface.nodes[0]!.next).toBe(2)
expect(s.surface.nodes[1]!.prev).toBe(3)
expect(s.surface.nodes[1]!.next).toBeNull()
expect(s.surface.nodes).toEqual([3, 2])
})
it('single-node replacement (start === end)', () => {
@@ -264,9 +248,7 @@ describe('SurfaceManager', () => {
{ provenance: { provider: 'mock', model: 'mock' }, turn: 1, step: 1, content: [{ type: 'text', text: 'x' }] },
{ surfaceOp: { op: 'replace', start: 1, end: 1 }, sourceEventSeqs: [1] },
) // seq 2
expect(s.surface.nodes.map(n => n.seq)).toEqual([0, 2])
expect(s.surface.nodes[0]!.next).toBe(2)
expect(s.surface.nodes[1]!.prev).toBe(0)
expect(s.surface.nodes).toEqual([0, 2])
})
it('throws when replace start is not found', () => {
@@ -310,7 +292,7 @@ describe('SurfaceManager', () => {
expect(logged.sourceEventSeqs).toEqual([0])
})
it('replace starting at non-head position links to previous node correctly', () => {
it('replace starting at non-head position preserves surrounding order', () => {
const s = new Session(SessionId('mid-replace'))
s.append('user/message', { content: [{ type: 'text', text: 'a' }], source: { kind: 'user' } }, { surfaceOp: 'append' }) // seq 0
s.append('user/message', { content: [{ type: 'text', text: 'b' }], source: { kind: 'user' } }, { surfaceOp: 'append' }) // seq 1
@@ -320,14 +302,7 @@ describe('SurfaceManager', () => {
{ provenance: { provider: 'mock', model: 'mock' }, turn: 1, step: 1, content: [{ type: 'text', text: 'x' }] },
{ surfaceOp: { op: 'replace', start: 1, end: 1 }, sourceEventSeqs: [1] },
) // seq 3
expect(s.surface.nodes.map(n => n.seq)).toEqual([0, 3, 2])
// Links: 0 → 3 → 2
expect(s.surface.nodes[0]!.prev).toBeNull()
expect(s.surface.nodes[0]!.next).toBe(3)
expect(s.surface.nodes[1]!.prev).toBe(0)
expect(s.surface.nodes[1]!.next).toBe(2)
expect(s.surface.nodes[2]!.prev).toBe(3)
expect(s.surface.nodes[2]!.next).toBeNull()
expect(s.surface.nodes).toEqual([0, 3, 2])
})
it('surfaceOp replace object is snapshot so caller mutation is isolated', () => {
@@ -501,7 +476,7 @@ describe('SurfaceManager.replaceGeneration', () => {
const nodes = s.surface.nodes
s.append('context/message', {
content: [{ type: 'text', text: 'summary' }], source: { kind: 'plugin', plugin: 'compact' },
}, { surfaceOp: { op: 'replace', start: nodes[0]!.seq, end: nodes[1]!.seq }, sourceEventSeqs: [nodes[0]!.seq, nodes[1]!.seq] })
}, { surfaceOp: { op: 'replace', start: nodes[0]!, end: nodes[1]! }, sourceEventSeqs: [nodes[0]!, nodes[1]!] })
expect(s.surface.replaceGeneration).toBe(1)
})
})