refactor(subagent): unify async readiness and cancellation

This commit is contained in:
Tianyi Cui
2026-07-12 22:41:59 +08:00
parent 02ca71db57
commit bb3f6bd736
49 changed files with 1350 additions and 4147 deletions
@@ -68,6 +68,7 @@ const WANT_PERMISSION = process.env.MOCK_PERMISSION === '1'
const NO_ALLOW = process.env.MOCK_NO_ALLOW === '1'
const THOUGHT = process.env.MOCK_THOUGHT === '1'
const CRASH_ON_CANCEL = process.env.MOCK_CRASH_ON_CANCEL === '1'
const CRASH_ON_PROMPT = process.env.MOCK_CRASH_ON_PROMPT === '1'
const IGNORE_CANCEL = process.env.MOCK_IGNORE_CANCEL === '1'
const READY_FILE = process.env.MOCK_READY_FILE
const FLUSH_ON_EOF = process.env.MOCK_FLUSH_ON_EOF
@@ -105,6 +106,7 @@ function makeAgent(conn: AgentSideConnection): Agent {
return Promise.resolve()
},
async prompt(params: PromptRequest): Promise<PromptResponse> {
if (CRASH_ON_PROMPT) process.exit(1)
if (WANT_PERMISSION) {
// Ask the client to approve before answering; honor its decision. Under
// MOCK_NO_ALLOW the only options are reject-shaped, so an `allow`-policy
@@ -225,4 +227,3 @@ if (process.env.MOCK_IGNORE_EOF === '1') {
setInterval(() => { /* stay alive past EOF until SIGTERM */ }, 1000)
if (READY_FILE !== undefined) writeFileSync(READY_FILE, 'ignore-eof-armed')
}
@@ -60,9 +60,10 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)('ACP backend with-key e2e (drive
},
})
const run = ctx.subagents.start('acp', {
const run = await ctx.subagents.start('acp', {
prompt: [{ type: 'text', text: 'Reply with exactly the word PONG and nothing else. Do not use any tools.' }],
parent: fakeParent,
signal: new AbortController().signal,
})
const result = await run.result
await run.dispose()
@@ -93,11 +94,12 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)('ACP backend with-key e2e (drive
},
})
const run = ctx.subagents.start('acp', {
const run = await ctx.subagents.start('acp', {
prompt: [{ type: 'text', text:
'Use the bash tool to write the text ACP_CHILD_WAS_HERE into a file named proof.txt '
+ 'in the current directory. Then reply DONE.' }],
parent: fakeParent,
signal: new AbortController().signal,
})
const result = await run.result
await run.dispose()
@@ -27,6 +27,10 @@ const repoTsconfig = fileURLToPath(new URL('../../../../tsconfig.json', import.m
/** A throwaway parent Agent — the ACP backend ignores it, but the seam requires one. */
const fakeParent = { id: 'parent', session: { header: {} } } as unknown as Agent
function request(text = 'p', signal = new AbortController().signal) {
return { prompt: [{ type: 'text' as const, text }], parent: fakeParent, signal }
}
interface SetupEnv {
/** Mock-server scripting env: MOCK_TEXT / MOCK_STOP / MOCK_HANG / MOCK_PERMISSION. */
[key: string]: string
@@ -119,7 +123,7 @@ describe('buildChildEnv', () => {
describe('dsh-subagent-acp', () => {
it('drives a child process to completion and returns its streamed output', async () => {
const ctx = await setup({ MOCK_TEXT: 'hello from acp child', MOCK_STOP: 'end_turn' })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'do X' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request('do X'))
const result = await run.result
expect(result.stopReason).toBe('completed')
expect(text(result.output)).toBe('hello from acp child')
@@ -128,7 +132,7 @@ describe('dsh-subagent-acp', () => {
it('maps a max_tokens stop reason', async () => {
const ctx = await setup({ MOCK_TEXT: 'cut off', MOCK_STOP: 'max_tokens' })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
const result = await run.result
expect(result.stopReason).toBe('max-tokens')
await run.dispose()
@@ -136,22 +140,23 @@ describe('dsh-subagent-acp', () => {
it('maps a refusal stop reason', async () => {
const ctx = await setup({ MOCK_TEXT: '', MOCK_STOP: 'refusal' })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
const result = await run.result
expect(result.stopReason).toBe('refusal')
await run.dispose()
})
it('cancelling a running child settles aborted (session/cancel via run.cancel)', async () => {
it('aborting the required signal cancels a running child', async () => {
const tmp = mkdtempSync(join(tmpdir(), 'acp-cancel-'))
const readyFile = join(tmp, 'ready')
try {
const ctx = await setup({ MOCK_TEXT: 'partial', MOCK_HANG: '1', MOCK_READY_FILE: readyFile })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const controller = new AbortController()
const run = await ctx.subagents.start('acp', request('p', controller.signal))
// Wait until the child's prompt is in flight (condition, not a sleep),
// then cancel — so we exercise the mid-run session/cancel path.
await waitForFile(readyFile)
run.cancel('test')
controller.abort('test')
const result = await run.result
expect(result.stopReason).toBe('aborted')
await run.dispose()
@@ -160,7 +165,7 @@ describe('dsh-subagent-acp', () => {
}
})
it('settles aborted WITHOUT spawning the child when the signal is already aborted', async () => {
it('rejects WITHOUT spawning the child when the signal is already aborted', async () => {
// A pre-aborted request must not even launch the configured binary. Point
// the command at one that would create a sentinel file if it ever ran, and
// assert the sentinel never appears.
@@ -169,17 +174,11 @@ describe('dsh-subagent-acp', () => {
try {
const controller = new AbortController()
controller.abort()
const run = startAcpRun(
{ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent, signal: controller.signal },
await expect(startAcpRun(
request('p', controller.signal),
// `touch <sentinel>` — runs only if the process is actually spawned.
{ command: 'touch', args: [sentinel], cwd: tmp, permission: 'reject', env: {}, disposeEofGraceMs: DEFAULT_DISPOSE_EOF_GRACE_MS, disposeGraceMs: DEFAULT_DISPOSE_GRACE_MS },
)
const result = await run.result
expect(result.stopReason).toBe('aborted')
expect(result.output).toEqual([])
// cancel/dispose on the inert run are safe no-ops.
run.cancel('noop')
await run.dispose()
)).rejects.toThrow('aborted before the ACP child started')
// The binary was never launched — no sentinel.
expect(existsSync(sentinel)).toBe(false)
} finally {
@@ -206,7 +205,7 @@ describe('dsh-subagent-acp', () => {
disposeEofGraceMs: 150,
disposeGraceMs: 150,
}
const run = startAcpRun({ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent }, spec)
const run = await startAcpRun(request(), spec)
// Wait until the child has BOOTED AND ARMED THE TRAP (a condition, not a
// sleep) — otherwise SIGTERM races the trap install and the default handler
// terminates the child, never exercising the escalation.
@@ -253,7 +252,7 @@ describe('dsh-subagent-acp', () => {
disposeEofGraceMs: 2000,
disposeGraceMs: 50,
}
const run = startAcpRun({ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent }, spec)
const run = await startAcpRun(request(), spec)
// Wait until the child is fully booted with its prompt in flight (its ACP
// stdin reader is attached), so dispose's stdin EOF reaches a live child.
await waitForFile(ready)
@@ -290,7 +289,7 @@ describe('dsh-subagent-acp', () => {
disposeEofGraceMs: 150,
disposeGraceMs: 2000,
}
const run = startAcpRun({ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent }, spec)
const run = await startAcpRun(request(), spec)
await waitForFile(ready)
// Bound it so a hang fails loud rather than stalling the suite.
await expect(Promise.race([
@@ -305,7 +304,7 @@ describe('dsh-subagent-acp', () => {
}
})
it('honors a cancel that races AHEAD of newSession (no session id yet) without running the prompt', async () => {
it('rejects after cleanup when the signal aborts during newSession', async () => {
// Gate the child at newSession: it signals `ready` and blocks until `go`.
// We cancel WHILE newSession is pending (sessionId still undefined, so the
// backend cannot send session/cancel) — the `cancelled` flag alone must
@@ -315,14 +314,12 @@ describe('dsh-subagent-acp', () => {
const go = join(tmp, 'go')
try {
const ctx = await setup({ MOCK_NEWSESSION_READY: ready, MOCK_NEWSESSION_GO: go, MOCK_TEXT: 'should not run' })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const controller = new AbortController()
const starting = ctx.subagents.start('acp', request('p', controller.signal))
await waitForFile(ready) // newSession is now in flight, sessionId undefined
run.cancel('early') // sets cancelled; cannot send session/cancel yet
controller.abort('early')
writeFileSync(go, 'go') // let newSession resolve
const result = await run.result
expect(result.stopReason).toBe('aborted')
expect(result.output).toEqual([])
await run.dispose()
await expect(starting).rejects.toThrow('aborted before the ACP child started')
} finally {
rmSync(tmp, { recursive: true, force: true })
}
@@ -334,7 +331,7 @@ describe('dsh-subagent-acp', () => {
try {
const controller = new AbortController()
const ctx = await setup({ MOCK_TEXT: 'partial', MOCK_HANG: '1', MOCK_READY_FILE: readyFile })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent, signal: controller.signal })
const run = await ctx.subagents.start('acp', request('p', controller.signal))
await waitForFile(readyFile)
controller.abort()
const result = await run.result
@@ -347,7 +344,7 @@ describe('dsh-subagent-acp', () => {
it('auto-rejects a permission prompt by default (child settles cancelled→aborted)', async () => {
const ctx = await setup({ MOCK_TEXT: 'x', MOCK_PERMISSION: '1' }, 'reject')
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
const result = await run.result
// The child asked permission, the backend rejected, the child returned cancelled.
expect(result.stopReason).toBe('aborted')
@@ -356,7 +353,7 @@ describe('dsh-subagent-acp', () => {
it('auto-approves a permission prompt under the allow policy', async () => {
const ctx = await setup({ MOCK_TEXT: 'approved answer', MOCK_PERMISSION: '1', MOCK_STOP: 'end_turn' }, 'allow')
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
const result = await run.result
expect(result.stopReason).toBe('completed')
expect(text(result.output)).toBe('approved answer')
@@ -367,7 +364,7 @@ describe('dsh-subagent-acp', () => {
// The child asks permission but offers ONLY reject-shaped options, so an
// allow-policy client finds nothing to select and must answer cancelled.
const ctx = await setup({ MOCK_PERMISSION: '1', MOCK_NO_ALLOW: '1' }, 'allow')
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
const result = await run.result
expect(result.stopReason).toBe('aborted')
await run.dispose()
@@ -377,7 +374,7 @@ describe('dsh-subagent-acp', () => {
// The child streams an agent_thought_chunk before its answer; the backend
// must consume it but NOT include it in the result output.
const ctx = await setup({ MOCK_THOUGHT: '1', MOCK_TEXT: 'final answer', MOCK_STOP: 'end_turn' })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
const result = await run.result
expect(result.stopReason).toBe('completed')
// Only the message text, NOT the thought.
@@ -385,18 +382,11 @@ describe('dsh-subagent-acp', () => {
await run.dispose()
})
it('resolves error (not reject) when the spawn command does not exist', async () => {
// Direct startAcpRun with NO onError sink — the catch must still flatten the
// spawn failure to `error` (the onError call is optional, covering the
// absent-sink branch).
const run = startAcpRun(
{ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent },
it('rejects a spawn failure after provider-owned cleanup', async () => {
await expect(startAcpRun(
request(),
{ command: '/nonexistent/acp-agent-binary', args: [], cwd: process.cwd(), permission: 'reject', env: {}, disposeEofGraceMs: DEFAULT_DISPOSE_EOF_GRACE_MS, disposeGraceMs: DEFAULT_DISPOSE_GRACE_MS },
)
const result = await run.result
// The seam contract: a child-level failure resolves error, never rejects.
expect(result.stopReason).toBe('error')
await run.dispose()
)).rejects.toThrow()
})
it('plugin-config dispose graces reach the run (SIGKILL escalation through the provider)', async () => {
@@ -418,7 +408,7 @@ describe('dsh-subagent-acp', () => {
disposeEofGraceMs: 150,
disposeGraceMs: 150,
})
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const run = await ctx.subagents.start('acp', request())
await waitForFile(ready)
await expect(Promise.race([
run.dispose(),
@@ -440,7 +430,7 @@ describe('dsh-subagent-acp', () => {
}
})
it('resolves error via the provider (real load path) when the command does not exist', async () => {
it('rejects a startup failure via the provider load path', async () => {
const ctx = new Context()
await ctx.plugin(SubagentService)
await ctx.plugin(acp, {
@@ -450,26 +440,23 @@ describe('dsh-subagent-acp', () => {
permission: 'reject',
env: {},
})
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const result = await run.result
expect(result.stopReason).toBe('error')
await run.dispose()
await expect(ctx.subagents.start('acp', request())).rejects.toThrow()
})
it('reports a flattened child failure through onError (preserved, not silently lost)', async () => {
// The seam forbids `result` rejecting, so a child-level failure is flattened
// to a stop reason — onError must still surface the original error so a real
// fault is logged, not swallowed. A nonexistent command triggers the spawn
// failure path; the spy records the error + the chosen stop reason.
// fault is logged, not swallowed. The child exits after its session is
// published but while prompt is in flight.
const errors: { message: string; stopReason: string }[] = []
const run = startAcpRun(
{ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent },
const run = await startAcpRun(
request(),
{
command: '/nonexistent/acp-agent-binary',
args: [],
command: process.execPath,
args: ['--import', tsxLoader, mockServer],
cwd: process.cwd(),
permission: 'reject',
env: {},
env: { MOCK_CRASH_ON_PROMPT: '1', TSX_TSCONFIG_PATH: repoTsconfig },
disposeEofGraceMs: DEFAULT_DISPOSE_EOF_GRACE_MS,
disposeGraceMs: DEFAULT_DISPOSE_GRACE_MS,
onError: (error, stopReason) => { errors.push({ message: error.message, stopReason }) },
@@ -487,14 +474,14 @@ describe('dsh-subagent-acp', () => {
// onError is a caller-supplied callback boundary: its own exception must be
// contained, or it would reject `result` and break the seam's "result never
// rejects" contract that the flattening above exists to uphold.
const run = startAcpRun(
{ prompt: [{ type: 'text', text: 'p' }], parent: fakeParent },
const run = await startAcpRun(
request(),
{
command: '/nonexistent/acp-agent-binary',
args: [],
command: process.execPath,
args: ['--import', tsxLoader, mockServer],
cwd: process.cwd(),
permission: 'reject',
env: {},
env: { MOCK_CRASH_ON_PROMPT: '1', TSX_TSCONFIG_PATH: repoTsconfig },
disposeEofGraceMs: DEFAULT_DISPOSE_EOF_GRACE_MS,
disposeGraceMs: DEFAULT_DISPOSE_GRACE_MS,
onError: () => { throw new Error('sink boom') },
@@ -514,9 +501,10 @@ describe('dsh-subagent-acp', () => {
const ready = join(tmp, 'ready')
try {
const ctx = await setup({ MOCK_TEXT: 'partial', MOCK_HANG: '1', MOCK_CRASH_ON_CANCEL: '1', MOCK_READY_FILE: ready })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const controller = new AbortController()
const run = await ctx.subagents.start('acp', request('p', controller.signal))
await waitForFile(ready)
run.cancel('crash it')
controller.abort('crash it')
const result = await run.result
expect(result.stopReason).toBe('aborted')
await run.dispose()
@@ -525,8 +513,8 @@ describe('dsh-subagent-acp', () => {
}
})
it('settles aborted on cancel even when the child IGNORES session/cancel (non-cooperative)', async () => {
// The contract: run.cancel() → result settles `aborted`. A child that hangs
it('settles aborted on signal even when the child IGNORES session/cancel', async () => {
// The signal contract requires `result` to settle `aborted`. A child that hangs
// its prompt AND ignores session/cancel must not wedge the parent — the
// backend's own cancel-settle path resolves `aborted` without the child's
// cooperation, and dispose() still reaps the process.
@@ -534,9 +522,10 @@ describe('dsh-subagent-acp', () => {
const ready = join(tmp, 'ready')
try {
const ctx = await setup({ MOCK_TEXT: 'partial', MOCK_HANG: '1', MOCK_IGNORE_CANCEL: '1', MOCK_READY_FILE: ready })
const run = ctx.subagents.start('acp', { prompt: [{ type: 'text', text: 'p' }], parent: fakeParent })
const controller = new AbortController()
const run = await ctx.subagents.start('acp', request('p', controller.signal))
await waitForFile(ready)
run.cancel('test')
controller.abort('test')
// Bound it: a regression (cancel only notifies the child, which ignores it)
// would hang result forever — fail loud instead of stalling the suite.
const result = await Promise.race([