Files
deepseek-harness/packages/core/agent-loop/tests/loop.spec.ts
T
Tianyi Cui 1323366da3 Merge worktree-hooks-b-bash-seam into worktree-hooks-c-interception
Bring the interception-seams branch onto current master (via A→B). The
substantive reconciliation is master's compaction `agent/pre-step` serial seam
meeting C's interception seams:

- types.ts: keep BOTH master's `agent/pre-step` AND C's new interception events
  (`agent/prompt-submit`, `agent/session-start`, `agent/turn-continuation`→
  `ContinuationDecision`); drop the turn-mirror declarations (removed on A).
- loop.ts: the merged per-turn order is `turn/start` → per queued msg
  `agent/prompt-submit` (rewrite/inject/block) → (fully-blocked ⇒ zero-step
  `rejected`) → per step: drain steering → assemble system prompt →
  `agent/pre-step` (compaction, OUTSIDE the step) → `step/start` → single
  `deriveMessages()` → model → tools/pre-execute·dispatch·post-execute. No
  turn-mirror emits; `closeTurn()` is the A-simplified single-call form.
- Docs (architecture, core.md, agent/agent-loop READMEs, catalog) reconciled to
  show C's interception seams alongside `agent/pre-step`, no turn/step mirrors.
- rfc/README: dropped the stale `proposed/` compaction row (master moved that RFC
  to implemented/); kept C's new `pre-tool-input-rewrite` proposed row.
- interception.spec.ts: migrated its two `agent/turn-end` reason collectors to
  the `turn/end` session event, and ADDED a cross-test proving a
  `prompt-submit` rewrite + additionalContext is VISIBLE to an `agent/pre-step`
  listener on the same turn — pinning the merged seam ordering (compaction sees
  the post-prompt-submit surface, not stale history).
2026-07-02 04:51:24 +08:00

817 lines
34 KiB
TypeScript

import { describe, expect, it } from 'vitest'
import { Context } from 'cordis'
import LlmService, { CallId, StreamChunk } from '@deepseek-ai/dsh-llm'
import SessionStore, { SessionId, TurnEndReason } from '@deepseek-ai/dsh-session'
import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
import ToolRegistry, { defineTool } from '@deepseek-ai/dsh-tools'
import AgentRegistry, { AgentId } from '@deepseek-ai/dsh-agent'
import AgentLoop, { ReactLoopAgent } from '@deepseek-ai/dsh-agent-loop'
import { MockAdapter, maxTokensResponse, textResponse, toolCallResponse } from './mock-adapter.ts'
async function harness(adapter: MockAdapter) {
const ctx = new Context()
await ctx.plugin(LlmService)
await ctx.plugin(SessionStore)
await ctx.plugin(SystemPrompt)
await ctx.plugin(ToolRegistry)
await ctx.plugin(AgentRegistry)
await ctx.plugin(AgentLoop, { agents: [] })
ctx.llm.registerAdapter(['mock'], adapter)
return ctx
}
/**
* Wait for the agent's NEXT transition to idle. Always event-based: callers
* invoke this right after send(), when the loop hasn't woken yet (status is
* still 'idle' synchronously), so polling the current status would lie.
*/
function waitForIdle(ctx: Context, agent: ReactLoopAgent): Promise<void> {
return new Promise((resolve) => {
const dispose = ctx.on('agent/status', (subject, status) => {
if (subject === agent && status === 'idle') {
dispose()
resolve()
}
})
})
}
function send(agent: ReactLoopAgent, text: string) {
agent.send([{ type: 'text', text }])
}
describe('agent loop', () => {
it('runs a simple turn: queued message → model → idle, with ordered events', async () => {
const adapter = new MockAdapter([textResponse('hello there')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
// All boundaries — turn and step — are durable session events on the
// session/event feed (no agent/* mirror). Record them in fire order to
// assert the full boundary nesting.
const order: string[] = []
ctx.on('session/event', (_session, event) => {
if (event.type === 'turn/start' || event.type === 'step/start' || event.type === 'step/end' || event.type === 'turn/end') {
order.push(event.type)
}
})
send(agent, 'hi')
await waitForIdle(ctx, agent)
expect(order).toEqual(['turn/start', 'step/start', 'step/end', 'turn/end'])
const types = agent.session.events.map(e => e.type)
// turn/start opens the turn, THEN the queued user message is recorded inside
// it (every event is turn-enclosed), then the assembled message (carrying the
// step's usage).
expect(types[0]).toBe('turn/start')
expect(types[1]).toBe('user/message')
expect(types).toContain('assistant/message')
const assistantMessage = agent.session.events.find(e => e.type === 'assistant/message')
expect(assistantMessage?.type === 'assistant/message' && assistantMessage.data.usage).toEqual({ inputTokens: 10, outputTokens: 'hello there'.length })
expect(types.at(-1)).toBe('turn/end')
// derived history: user + assistant
const messages = agent.session.deriveMessages()
expect(messages.map(m => m.role)).toEqual(['user', 'assistant'])
expect(messages[1]!.content).toEqual([{ type: 'text', text: 'hello there' }])
})
it('round-trips tool calls: model requests tool → executes → result in next request', async () => {
const adapter = new MockAdapter([
toolCallResponse('c1', 'echo', { text: 'ping' }, 'calling echo'),
textResponse('done'),
])
const ctx = await harness(adapter)
ctx.tools.register(defineTool({
name: 'echo',
description: 'echo back',
parameters: { text: { type: 'string' } },
async execute(args) {
return [{ type: 'text', text: `echo: ${args.text}` }]
},
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
send(agent, 'use the tool')
await waitForIdle(ctx, agent)
// two model calls happened (tool-call step, then final step)
expect(adapter.requests).toHaveLength(2)
// the second request's derived history contains the tool result
const secondMessages = adapter.requests[1]!.messages
const toolResultMessage = secondMessages.find(m =>
m.content.some(b => b.type === 'tool-result'))
expect(toolResultMessage).toBeDefined()
const block = toolResultMessage!.content.find(b => b.type === 'tool-result')!
expect(block).toMatchObject({ toolCallId: 'c1', isError: false })
expect((block).content).toEqual([{ type: 'text', text: 'echo: ping' }])
// session log records call + result
const types = agent.session.events.map(e => e.type)
expect(types).toContain('tool/call')
expect(types).toContain('tool/result')
})
it('passes assembled system prompt and tool schemas into the request', async () => {
const adapter = new MockAdapter([textResponse('ok')])
const ctx = await harness(adapter)
ctx.systemPrompt.section({ name: 'persona', order: 0, text: 'You are a test agent.' })
ctx.tools.register(defineTool({
name: 'noop',
description: 'does nothing',
parameters: {},
async execute() {
return []
},
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock', systemPrompt: 'Agent-specific suffix.' })
send(agent, 'hi')
await waitForIdle(ctx, agent)
const request = adapter.requests[0]
expect(request!.system).toBe('You are a test agent.\n\nAgent-specific suffix.')
expect(request!.tools?.map(t => t.name)).toEqual(['noop'])
})
it('records raw chunks for replay and emits agent/stream-chunk', async () => {
const adapter = new MockAdapter([textResponse('abc')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const streamed: StreamChunk[] = []
ctx.on('agent/stream-chunk', (_agent, _turn, _step, chunk) => void streamed.push(chunk))
send(agent, 'hi')
await waitForIdle(ctx, agent)
const chunkEvents = agent.session.events.filter(e => e.type === 'assistant/chunk')
// textResponse('abc') = block-start + 3 deltas + block-end + usage + finish = 7
expect(chunkEvents).toHaveLength(7)
expect(streamed).toHaveLength(7)
// replay: chunk events alone re-assemble to the recorded assistant message
const deltaText = chunkEvents
.flatMap(e => e.type === 'assistant/chunk' ? [e.data.chunk] : [])
.filter((c: StreamChunk): c is Extract<StreamChunk, { type: 'text-delta' }> => c.type === 'text-delta')
.map(c => c.text)
.join('')
expect(deltaText).toBe('abc')
})
it('injects steering between steps and continues the turn', async () => {
const adapter = new MockAdapter([
toolCallResponse('c1', 'slow', {}),
textResponse('addressed the steering'),
])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
ctx.tools.register(defineTool({
name: 'slow',
description: '',
parameters: {},
async execute() {
// steer while the turn is running (during tool execution)
agent.steer([{ type: 'text', text: 'change of plans' }])
return [{ type: 'text', text: 'tool done' }]
},
}))
send(agent, 'start')
await waitForIdle(ctx, agent)
const types = agent.session.events.map(e => e.type)
expect(types).toContain('steering/message')
// steering recorded before the second step's request derived its history
const steeringSeq = agent.session.events.find(e => e.type === 'steering/message')!.seq
const secondStepStart = agent.session.events.filter(e => e.type === 'step/start')[1]
expect(secondStepStart).toBeDefined()
expect(steeringSeq).toBeLessThan(secondStepStart!.seq)
// the second model request saw the steering content
const secondRequest = adapter.requests[1]
const flat = JSON.stringify(secondRequest!.messages)
expect(flat).toContain('change of plans')
})
it('steering while idle behaves like send (starts a turn)', async () => {
const adapter = new MockAdapter([textResponse('ok')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
agent.steer([{ type: 'text', text: 'hello' }])
await waitForIdle(ctx, agent)
expect(agent.session.events.some(e => e.type === 'user/message')).toBe(true)
})
it('inject() while idle wraps context in a one-shot turn, visible to the next request', async () => {
const adapter = new MockAdapter([textResponse('ok')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
agent.inject([{ type: 'text', text: 'file changed: a.ts' }], { source: { kind: 'plugin', plugin: 'watcher' } })
// The idle inject records a self-contained turn (turn/start → context/message
// → turn/end) so the event stays turn-enclosed, but does NOT run the model.
await new Promise(r => setTimeout(r, 20))
expect(agent.status).toBe('idle')
expect(adapter.requests).toHaveLength(0)
const injectedTurn = agent.session.events.filter(e => e.type === 'turn/start')
expect(injectedTurn).toHaveLength(1)
const it0 = injectedTurn[0]!
expect(it0.type === 'turn/start' && it0.data.trigger.kind).toBe('injection')
expect(agent.session.events.at(-1)!.type).toBe('turn/end') // turn-enclosed
send(agent, 'go')
await waitForIdle(ctx, agent)
const flat = JSON.stringify(adapter.requests[0]!.messages)
expect(flat).toContain('file changed: a.ts')
expect(flat).toContain('<context source=\\"plugin\\">')
})
it('inject() while running appends into the open turn (no extra synthetic turn)', async () => {
const adapter = new MockAdapter([
toolCallResponse('c1', 'noticer', {}, 'calling'),
textResponse('done'),
])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
// A tool that injects mid-execution: at this point the agent is running, so
// inject must append the context/message into the ALREADY-open turn rather
// than wrap it in its own one-shot turn.
ctx.tools.register(defineTool({
name: 'noticer',
description: 'injects a notice',
parameters: {},
async execute() {
agent.inject([{ type: 'text', text: 'mid-turn notice' }], { source: { kind: 'plugin', plugin: 'x' } })
return [{ type: 'text', text: 'ok' }]
},
}))
send(agent, 'go')
await waitForIdle(ctx, agent)
// Exactly ONE turn ran (no synthetic injection turn), and the mid-turn
// context/message sits inside it.
const turnStarts = agent.session.events.filter(e => e.type === 'turn/start')
expect(turnStarts).toHaveLength(1)
const ts0 = turnStarts[0]!
expect(ts0.type === 'turn/start' && ts0.data.trigger.kind).toBe('message')
expect(agent.session.events.some(e => e.type === 'context/message')).toBe(true)
})
it('agent/turn-continuation can force-continue (/loop pattern) and force-stop', async () => {
// force-continue: model never calls tools, but a plugin forces 3 steps
const adapter = new MockAdapter([
textResponse('step 1'),
textResponse('step 2'),
textResponse('step 3'),
])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
let steps = 0
ctx.on('session/event', (_session, event) => { if (event.type === 'step/end') steps++ })
ctx.on('agent/turn-continuation', async (_agent, _turn, _defaultDecision, next) => {
if (steps < 3) return { action: 'continue' as const }
return next()
})
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(steps).toBe(3)
expect(adapter.requests).toHaveLength(3)
})
it('agent/turn-continuation can veto continuation despite tool calls (budget-guard pattern)', async () => {
const adapter = new MockAdapter([toolCallResponse('c1', 'echo', { text: 'x' })])
const ctx = await harness(adapter)
ctx.tools.register(defineTool({
name: 'echo',
description: '',
parameters: { text: { type: 'string' } },
async execute(args) {
return [{ type: 'text', text: String(args.text) }]
},
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
ctx.on('agent/turn-continuation', async () => ({ action: 'stop' }) as const)
send(agent, 'go')
await waitForIdle(ctx, agent)
// only one model call despite the tool call requesting a follow-up
expect(adapter.requests).toHaveLength(1)
// tool still executed before the decision
expect(agent.session.events.some(e => e.type === 'tool/result')).toBe(true)
})
it('agent/request waterfall can rewrite the request (model-switch pattern)', async () => {
const adapter = new MockAdapter([textResponse('ok')])
const ctx = await harness(adapter)
ctx.llm.registerAdapter(['other-model'], adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
ctx.on('agent/request', async (_agent, _turn, _step, options, next) => {
options.model = 'other-model'
return next()
})
send(agent, 'hi')
await waitForIdle(ctx, agent)
expect(adapter.requests[0]!.model).toBe('other-model')
})
it('agent/pre-step fires once per step before the step is opened', async () => {
// Two steps (a tool call, then a final text turn) → two model calls → two
// pre-step fires, each carrying the assembled full system prompt, BEFORE
// the step is opened and its request is derived (the request the adapter
// sees reflects any surface state at fire time).
const adapter = new MockAdapter([
toolCallResponse('c1', 'echo', {}, 'calling echo'),
textResponse('done'),
])
const ctx = await harness(adapter)
ctx.tools.register(defineTool({
name: 'echo', description: 'echo', parameters: {},
async execute() { return [{ type: 'text', text: 'echoed' }] },
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const fires: { turn: number; step: number; fullSystemPrompt: string }[] = []
ctx.on('agent/pre-step', (subject, turn, step, fullSystemPrompt) => {
if (subject === agent) fires.push({ turn, step, fullSystemPrompt })
})
send(agent, 'go')
await waitForIdle(ctx, agent)
// One fire per step, in order, each with the assembled system prompt.
expect(fires).toEqual([
{ turn: 1, step: 1, fullSystemPrompt: '' },
{ turn: 1, step: 2, fullSystemPrompt: '' },
])
})
it('agent/pre-step fires BEFORE the step it precedes opens (events land outside the step)', async () => {
// A listener appending a surface node in pre-step lands it BEFORE step/start
// in the log — proving the seam fires outside the step. The node is still in
// the derived request for that step (derive happens after step/start).
const adapter = new MockAdapter([textResponse('ok')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
let injected = false
ctx.on('agent/pre-step', (subject) => {
if (subject === agent && !injected) {
injected = true
subject.session.append('context/message', {
content: [{ type: 'text', text: 'INJECTED-IN-PRE-STEP' }],
source: { kind: 'plugin', plugin: 'test' },
}, { surfaceOp: 'append' })
}
})
send(agent, 'go')
await waitForIdle(ctx, agent)
// The adapter's request includes the node injected during pre-step (derive
// reflects it).
const text = JSON.stringify(adapter.requests[0]!.messages)
expect(text).toContain('INJECTED-IN-PRE-STEP')
// And the injected event sits BEFORE the first step/start in the log —
// the seam fired outside the step.
const events = agent.session.events
const injectedSeq = events.find(e => e.type === 'context/message')!.seq
const firstStepStartSeq = events.find(e => e.type === 'step/start')!.seq
expect(injectedSeq).toBeLessThan(firstStepStartSeq)
})
it('a throwing agent/pre-step listener ends the turn (error), not the loop', async () => {
// The seam fires before step/start, so a throw escapes to runTurn's outer
// catch: the not-yet-open step closes as a no-op, the failure surfaces via
// agent/error, and the turn ends `error` (recorded on the durable turn/end).
// The loop survives and a follow-up prompt still runs.
const adapter = new MockAdapter([textResponse('second turn ok')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
let throwOnce = true
ctx.on('agent/pre-step', () => {
if (throwOnce) { throwOnce = false; throw new Error('boom in pre-step') }
})
const errors: Error[] = []
ctx.on('agent/error', (_a, _t, _s, error) => void errors.push(error))
send(agent, 'first')
await waitForIdle(ctx, agent)
// The first turn failed at step 1 (no model call happened), surfaced via
// agent/error, with the durable failure on turn/end.reason.
expect(errors).toHaveLength(1)
expect(errors[0]!.message).toContain('boom in pre-step')
expect(adapter.requests.length).toBe(0)
const firstTurnEnd = agent.session.events.find(e => e.type === 'turn/end')
expect(firstTurnEnd?.type === 'turn/end' && firstTurnEnd.data.reason).toMatchObject({ kind: 'error', step: 1 })
// The step opened-and-closed count stays balanced even though it never ran.
const types = agent.session.events.map(e => e.type)
expect(types.filter(t => t === 'step/start').length).toBe(types.filter(t => t === 'step/end').length)
// The loop survived: a second prompt runs a normal completed turn.
send(agent, 'second')
await waitForIdle(ctx, agent)
expect(adapter.requests.length).toBe(1)
const lastTurnEnd = agent.session.events.findLast(e => e.type === 'turn/end')
expect(lastTurnEnd?.type === 'turn/end' && lastTurnEnd.data.reason).toEqual({ kind: 'completed' })
})
it('cancel() mid-stream ends the turn with reason aborted', async () => {
const adapter = new MockAdapter(['hang'])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'go')
// wait until the stream is hanging, then cancel
await new Promise(r => setTimeout(r, 30))
expect(agent.status).toBe('running')
agent.cancel('user interrupt')
await waitForIdle(ctx, agent)
expect(reasons).toEqual([{ kind: 'aborted', reason: 'user interrupt' }])
})
it('surfaces max-tokens as the turn-end reason when the last step is cut off', async () => {
// A single step that ends with a max-tokens finish (no tool calls): the
// turn stops by default and ends max-tokens, not completed.
const adapter = new MockAdapter([maxTokensResponse('truncat')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(adapter.requests).toHaveLength(1)
expect(reasons).toEqual([{ kind: 'max-tokens' }])
// and the reason is recorded in the log's turn/end event
const turnEnd = agent.session.events.findLast(e => e.type === 'turn/end')
expect(turnEnd!.data.reason).toEqual({ kind: 'max-tokens' })
})
it('a max-tokens step earlier in a turn still surfaces as max-tokens after a later completed step', async () => {
// Step 1 is cut off (max-tokens, no tool calls → would stop by default), so
// continuation must be FORCED to reach step 2 which finishes normally
// (stop). The rule "any max-tokens step surfaces as max-tokens" means the
// turn ends max-tokens even though the LAST step completed cleanly.
const adapter = new MockAdapter([
maxTokensResponse('first half'),
textResponse('second half'),
])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
let steps = 0
ctx.on('session/event', (_session, event) => { if (event.type === 'step/end') steps++ })
// Force exactly one continuation (step 1 → step 2), then defer to default
// (step 2 is a plain stop with no tool calls → stops).
ctx.on('agent/turn-continuation', async (_agent, _turn, _defaultDecision, next) => {
if (steps < 2) return { action: 'continue' as const }
return next()
})
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(steps).toBe(2)
expect(adapter.requests).toHaveLength(2)
expect(adapter.requests[1]!.messages).toEqual([
{ role: 'user', content: [{ type: 'text', text: 'go' }] },
{ role: 'assistant', content: [{ type: 'text', text: 'first half' }] },
])
expect(reasons).toEqual([{ kind: 'max-tokens' }])
})
it('a completed step after no max-tokens keeps the turn completed (max-tokens does not leak across turns)', async () => {
// Two consecutive turns: turn 1 is cut off (max-tokens), turn 2 is a clean
// stop. The per-turn reason must be independent — turn 2 ends completed.
const adapter = new MockAdapter([maxTokensResponse('cut'), textResponse('clean')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'first')
await waitForIdle(ctx, agent)
send(agent, 'second')
await waitForIdle(ctx, agent)
expect(reasons).toEqual([{ kind: 'max-tokens' }, { kind: 'completed' }])
})
it('does not dispatch tool calls from a max-tokens-truncated step', async () => {
const callId = CallId('c1')
const adapter = new MockAdapter([[
{ type: 'block-start', index: 0, blockType: 'tool-call' },
{ type: 'tool-call-delta', index: 0, id: callId, name: 'echo', argumentsDelta: '{"text":"x"}' },
{ type: 'block-end', index: 0, block: { type: 'tool-call', id: callId, name: 'echo', arguments: '{"text":"x"}' } },
{ type: 'usage', usage: { inputTokens: 10, outputTokens: 5 } },
{ type: 'finish', reason: { kind: 'max-tokens' } },
]])
const ctx = await harness(adapter)
let executions = 0
ctx.tools.register(defineTool({
name: 'echo',
description: '',
parameters: { text: { type: 'string' } },
async execute() {
executions += 1
return [{ type: 'text', text: 'should not run' }]
},
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(executions).toBe(0)
expect(agent.session.events.some(e => e.type === 'tool/call')).toBe(false)
expect(agent.session.deriveMessages()).toEqual([{ role: 'user', content: [{ type: 'text', text: 'go' }] }])
expect(reasons).toEqual([{ kind: 'max-tokens' }])
// No-data-loss: a max-tokens step whose only content was a dropped tool call
// has EMPTY assistant content, but its usage must still be represented. It
// rides on an (empty-content) assistant/message — there is no standalone
// usage event — and that empty message is skipped by deriveMessages(), so
// the derived history above is NOT corrupted by a spurious assistant turn.
const assistantMessage = agent.session.events.find(e => e.type === 'assistant/message')
expect(assistantMessage?.type === 'assistant/message' && assistantMessage.data).toEqual({
turn: 1, step: 1, content: [], usage: { inputTokens: 10, outputTokens: 5 },
})
})
it('appends no assistant/message for a max-tokens step with empty content and no usage', async () => {
// A max-tokens step truncated to a dropped tool call AND with no usage chunk
// has nothing to record: empty content and no accounting → no assistant/message
// (the empty-content host exists only to carry usage). The turn still ends
// max-tokens.
const callId = CallId('c1')
const adapter = new MockAdapter([[
{ type: 'block-start', index: 0, blockType: 'tool-call' },
{ type: 'tool-call-delta', index: 0, id: callId, name: 'echo', argumentsDelta: '{"text":"x"}' },
{ type: 'block-end', index: 0, block: { type: 'tool-call', id: callId, name: 'echo', arguments: '{"text":"x"}' } },
{ type: 'finish', reason: { kind: 'max-tokens' } },
]])
const ctx = await harness(adapter)
ctx.tools.register(defineTool({
name: 'echo',
description: '',
parameters: { text: { type: 'string' } },
async execute() { return [{ type: 'text', text: 'should not run' }] },
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(reasons).toEqual([{ kind: 'max-tokens' }])
expect(agent.session.events.some(e => e.type === 'assistant/message')).toBe(false)
expect(agent.session.deriveMessages()).toEqual([{ role: 'user', content: [{ type: 'text', text: 'go' }] }])
})
it('appends no assistant/message for a normal stop finish with empty content and no usage', async () => {
// A clean `stop` finish that streamed nothing assembled (no blocks) and
// carried no usage chunk has nothing to record: the content-or-usage guard
// on the normal step path suppresses a pure trace-only empty assistant/message.
const adapter = new MockAdapter([[{ type: 'finish', reason: { kind: 'stop' } }]])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const reasons: TurnEndReason[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(reasons).toEqual([{ kind: 'completed' }])
expect(agent.session.events.some(e => e.type === 'assistant/message')).toBe(false)
expect(agent.session.deriveMessages()).toEqual([{ role: 'user', content: [{ type: 'text', text: 'go' }] }])
})
it('keeps safe max-tokens assistant content while dropping truncated tool calls', async () => {
const callId = CallId('c1')
const adapter = new MockAdapter([[
{ type: 'block-start', index: 0, blockType: 'text' },
{ type: 'text-delta', index: 0, text: 'partial text' },
{ type: 'block-end', index: 0, block: { type: 'text', text: 'partial text' } },
{ type: 'block-start', index: 1, blockType: 'tool-call' },
{ type: 'tool-call-delta', index: 1, id: callId, name: 'echo', argumentsDelta: '{"text"' },
{ type: 'finish', reason: { kind: 'max-tokens' } },
]])
const ctx = await harness(adapter)
let stepResults = 0
ctx.on('agent/step-result', async (_agent, _turn, _step, message, next) => {
stepResults += 1
expect(message.content).toEqual([{ type: 'text', text: 'partial text' }])
return next()
})
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(stepResults).toBe(1)
expect(agent.session.events.some(e => e.type === 'tool/call')).toBe(false)
expect(agent.session.deriveMessages()).toEqual([
{ role: 'user', content: [{ type: 'text', text: 'go' }] },
{ role: 'assistant', content: [{ type: 'text', text: 'partial text' }] },
])
})
it('stops the turn when a step/end session-event listener failure has recorded an error', async () => {
const adapter = new MockAdapter([
toolCallResponse('c1', 'echo', { text: 'x' }),
textResponse('should not run'),
])
const ctx = await harness(adapter)
ctx.tools.register(defineTool({
name: 'echo',
description: '',
parameters: { text: { type: 'string' } },
async execute(args) {
return [{ type: 'text', text: String(args.text) }]
},
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
let threw = false
// A throwing step/end session-event listener is the surviving boundary-listener
// failure path (step boundaries have no agent/* mirror): closeStep contains it
// and surfaces it as a turn error rather than stranding the turn open.
ctx.on('session/event', (_session, event) => {
if (event.type === 'step/end' && !threw) { threw = true; throw new Error('bad step/end listener') }
})
send(agent, 'go')
await waitForIdle(ctx, agent)
expect(adapter.requests).toHaveLength(1)
const turnEnd = agent.session.events.findLast(e => e.type === 'turn/end')
expect(turnEnd?.type === 'turn/end' && turnEnd.data.reason.kind).toBe('error')
})
it('chains queued messages into consecutive turns', async () => {
const adapter = new MockAdapter([textResponse('first'), textResponse('second')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const turns: number[] = []
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/start') turns.push(event.data.turn) })
// queue two messages while idle — first starts turn 1 immediately;
// queue the second during turn 1 via a stream-chunk hook
let queued = false
ctx.on('agent/stream-chunk', () => {
if (!queued) {
queued = true
send(agent, 'second message')
}
})
send(agent, 'first message')
await waitForIdle(ctx, agent)
expect(turns).toEqual([1, 2])
expect(adapter.requests).toHaveLength(2)
})
it('awaits session/flush at turn end (persistence checkpoint)', async () => {
const adapter = new MockAdapter([textResponse('ok')])
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
let flushed = 0
let flushedBeforeIdle = false
ctx.on('session/flush', async (session) => {
await new Promise(r => setTimeout(r, 10))
flushed++
flushedBeforeIdle = agent.status !== 'idle'
void session
})
send(agent, 'hi')
await waitForIdle(ctx, agent)
expect(flushed).toBe(1)
expect(flushedBeforeIdle).toBe(true)
})
it('errors from the model surface as agent/error and end the turn', async () => {
const adapter = new MockAdapter([]) // script exhausted → throws
const ctx = await harness(adapter)
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
const errors: Error[] = []
const reasons: TurnEndReason[] = []
ctx.on('agent/error', (_agent, _turn, _step, error) => void errors.push(error))
ctx.on('session/event', (_s, event) => { if (event.type === 'turn/end') reasons.push(event.data.reason) })
send(agent, 'hi')
await waitForIdle(ctx, agent)
expect(errors).toHaveLength(1)
expect(errors[0]!.message).toContain('script exhausted')
expect(reasons[0]).toMatchObject({ kind: 'error' })
// The durable failure lives entirely on turn/end.reason (with the failing
// step), not a standalone error event.
const turnEnd = agent.session.events.find(e => e.type === 'turn/end')
expect(turnEnd?.type === 'turn/end' && turnEnd.data.reason).toMatchObject({ kind: 'error', step: 1 })
})
it('disposing the loop fiber mid-turn stops the loop (HMR safety)', async () => {
const adapter = new MockAdapter(['hang'])
const ctx = await harness(adapter)
let agent!: ReactLoopAgent
const fiber = await ctx.plugin(Object.assign((inner: Context) => {
agent = inner.agentLoop.create(AgentId('scoped'), { model: 'mock' })
}, { inject: ['agentLoop'] }))
expect(ctx.agents.get(AgentId('scoped'))).toBe(agent)
send(agent, 'go')
await new Promise(r => setTimeout(r, 30))
expect(agent.status).toBe('running')
await fiber.dispose()
await agent.done
expect(agent.status).toBe('disposed')
expect(ctx.agents.get(AgentId('scoped'))).toBeUndefined()
expect(() => { send(agent, 'too late') }).toThrow('disposed')
})
it('creates agents from config on startup', async () => {
const adapter = new MockAdapter([textResponse('from config')])
const ctx = new Context()
await ctx.plugin(LlmService)
await ctx.plugin(SessionStore)
await ctx.plugin(SystemPrompt)
await ctx.plugin(ToolRegistry)
await ctx.plugin(AgentRegistry)
await ctx.plugin(AgentLoop, {
agents: [{ id: AgentId('config-agent'), model: 'mock', systemPrompt: 'Config prompt' }],
})
ctx.llm.registerAdapter(['mock'], adapter)
const agent = ctx.agents.get(AgentId('config-agent'))! as ReactLoopAgent
expect(agent).toBeDefined()
expect(agent.id).toBe('config-agent')
expect(agent.options.model).toBe('mock')
// the agent is alive: send triggers a turn
send(agent, 'hi')
await waitForIdle(ctx, agent)
expect(adapter.requests).toHaveLength(1)
})
it('replays a session log into an identical derived history', async () => {
const adapter = new MockAdapter([
toolCallResponse('c1', 'echo', { text: 'x' }),
textResponse('done'),
])
const ctx = await harness(adapter)
ctx.tools.register(defineTool({
name: 'echo',
description: '',
parameters: { text: { type: 'string' } },
async execute(args) {
return [{ type: 'text', text: String(args.text) }]
},
}))
const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
send(agent, 'run')
await waitForIdle(ctx, agent)
const replayed = ctx.sessions.create(SessionId('replayed'), { seed: [...agent.session.events] })
expect(replayed.deriveMessages()).toEqual(agent.session.deriveMessages())
// event-by-event identity of types
expect(replayed.events.map(e => e.type)).toEqual(
agent.session.events.map(e => e.type))
})
})