fix(invariants): assert runtime relationships, not API shapes

packages/hooks/hook-protocol/src/invariant.ts

@@ -1,39 +1,98 @@
-/** Package-owned runtime contracts for @deepseek-ai/dsh-hook-protocol. @module @deepseek-ai/dsh-hook-protocol/invariant */
+/** Package-owned hook provenance-stream invariants. @module @deepseek-ai/dsh-hook-protocol/invariant */
 
-/* jscpd:ignore-start */
 import type { Context } from 'cordis'
-import { assertInvariant, type InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+import type { Session, SessionEvent } from '@deepseek-ai/dsh-session'
+import type { InvariantFailure, InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+import type {} from './types.ts'
 
 const PACKAGE_NAME = '@deepseek-ai/dsh-hook-protocol'
 
 /** Cordis companion plugin name. */
 export const name = 'hook-protocol-invariant'
-/** Services required before the companion can register. */
+/** Service required before the companion can reserve package ownership. */
 export const inject = ['invariants']
 
-/** Assert blocking-exit decoding and restrictive merge precedence. */
-const install: InvariantInstaller = async (_ctx, fail) => {
-  const [{ parseHookOutput }, { mergeHookOutputs }] = await Promise.all([
-    import('./codec.ts'),
-    import('./merge.ts'),
-  ])
-  const blocked = parseHookOutput(2, '', ' denied ')
-  assertInvariant(fail, blocked.decision === 'block' && blocked.reason === 'denied',
-    'exit 2 must decode as a block whose reason is trimmed stderr')
-
-  const merged = mergeHookOutputs([
-    { exitCode: 0, stderr: '', stdout: '', decision: 'allow', reason: 'permitted' },
-    { exitCode: 0, stderr: '', stdout: '', decision: 'deny', reason: 'forbidden' },
-  ])
-  assertInvariant(fail, merged.decision === 'deny' && merged.reason === 'forbidden',
-    'deny must override allow and retain only the winning decision reason')
+interface HookTransition {
+  key: string
+  delta: 1 | -1
 }
 
+/** Correlation key shared by an invoked/result pair. */
+function hookKey(data: { turn: number; point: string; handlerId: string }): string {
+  return `${data.turn}\0${data.point}\0${data.handlerId}`
+}
+
+/** Validate one hook event against committed pending invocations. */
+function validateHookEvent(
+  pending: ReadonlyMap<string, number>,
+  event: SessionEvent,
+  fail: InvariantFailure,
+): HookTransition | undefined {
+  if (event.type === 'hook/invoked') {
+    if (event.data.point.length === 0 || event.data.handlerId.length === 0) {
+      fail('hook/invoked point and handlerId must be non-empty')
+    }
+    const dialect: string = event.data.dialect
+    if (dialect !== 'claude' && dialect !== 'codex') {
+      fail(`hook/invoked carries unknown dialect ${JSON.stringify(dialect)}`)
+    }
+    return { key: hookKey(event.data), delta: 1 }
+  }
+  if (event.type !== 'hook/result') return undefined
+  const key = hookKey(event.data)
+  if ((pending.get(key) ?? 0) === 0) {
+    fail(`hook/result has no matching hook/invoked for ${JSON.stringify(event.data.handlerId)}`)
+  }
+  if (!Number.isFinite(event.data.durationMs) || event.data.durationMs < 0) {
+    fail('hook/result durationMs must be a non-negative finite number')
+  }
+  return { key, delta: -1 }
+}
+
+/** Apply one committed hook-pair transition. */
+function applyHookTransition(pending: Map<string, number>, transition: HookTransition): void {
+  const next = (pending.get(transition.key) ?? 0) + transition.delta
+  if (next === 0) pending.delete(transition.key)
+  else pending.set(transition.key, next)
+}
+
+/** Install hook invoked/result pairing checks. */
+const install: InvariantInstaller = Object.assign((ctx: Context, fail: InvariantFailure) => {
+  const traces = new WeakMap<Session, Map<string, number>>()
+  const staged = new WeakMap<SessionEvent, { session: Session; transition: HookTransition }>()
+  const seed = (session: Session): Map<string, number> => {
+    const pending = new Map<string, number>()
+    traces.set(session, pending)
+    for (const event of session.events) {
+      const transition = validateHookEvent(pending, event, fail)
+      if (transition !== undefined) applyHookTransition(pending, transition)
+    }
+    return pending
+  }
+  const traceFor = (session: Session): Map<string, number> => traces.get(session) ?? seed(session)
+
+  for (const session of ctx.sessions.list()) seed(session)
+  ctx.on('session/created', (session) => { seed(session) }, { global: true })
+  ctx.on('session/event', (session, event) => {
+    if (event.type !== 'hook/invoked' && event.type !== 'hook/result') return
+    const candidate = staged.get(event)
+    /* v8 ignore next -- internal/dispatch stages every hook provenance event */
+    if (candidate === undefined || candidate.session !== session) return fail('hook event published without pre-commit validation')
+    staged.delete(event)
+    applyHookTransition(traceFor(session), candidate.transition)
+  }, { global: true })
+  ctx.on('internal/dispatch', (_mode, eventName, args) => {
+    if (eventName !== 'session/event') return
+    const [session, event] = args as [Session, SessionEvent]
+    const transition = validateHookEvent(traceFor(session), event, fail)
+    if (transition !== undefined) staged.set(event, { session, transition })
+  }, { global: true })
+}, { inject: ['sessions'] })
+
 /**
- * Register this package's invariant companion.
+ * Register the hook-protocol invariant companion.
  * @param ctx - Cordis context carrying the invariant service.
  * @returns the installed registration's disposer after setup succeeds.
  */
 export const apply = (ctx: Context): Promise<() => void> =>
   Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
-/* jscpd:ignore-end */

packages/hooks/hook-protocol/tests/invariant.spec.ts

@@ -0,0 +1,86 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import SessionStore, { Session, SessionId } from '@deepseek-ai/dsh-session'
+import * as HookInvariant from '@deepseek-ai/dsh-hook-protocol/invariant'
+import InvariantService from '@deepseek-ai/dsh-invariants'
+
+async function setup(): Promise<Context> {
+  const ctx = new Context()
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(InvariantService)
+  await ctx.plugin(HookInvariant)
+  return ctx
+}
+
+const invoked = (overrides: Record<string, unknown> = {}) => ({
+  turn: 1,
+  point: 'PreToolUse',
+  dialect: 'claude' as const,
+  handlerId: 'hook-1',
+  ...overrides,
+})
+
+const result = (overrides: Record<string, unknown> = {}) => ({
+  turn: 1,
+  point: 'PreToolUse',
+  handlerId: 'hook-1',
+  decision: 'pass',
+  durationMs: 3,
+  ...overrides,
+})
+
+describe('hook-protocol invariants', () => {
+  it('pairs serial and repeated handler invocations', async () => {
+    const ctx = await setup()
+    const session = ctx.sessions.create()
+    session.append('hook/invoked', invoked())
+    session.append('hook/invoked', invoked())
+    session.append('hook/result', result())
+    session.append('hook/result', result())
+  })
+
+  it('rebuilds pending hook provenance from an existing session', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    const session = ctx.sessions.create()
+    session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
+    session.append('hook/invoked', invoked())
+    await ctx.plugin(InvariantService)
+    await ctx.plugin(HookInvariant)
+    expect(() => session.append('hook/result', result())).not.toThrow()
+    session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+  })
+
+  it('adopts a bare session first observed through publication', async () => {
+    const ctx = await setup()
+    const session = new Session(SessionId('bare-hook-session'))
+    expect(() => {
+      ctx.emit('session/event', session, {
+        type: 'hook/invoked', seq: 0, time: 0, data: invoked(),
+      })
+      ctx.emit('session/event', session, {
+        type: 'hook/result', seq: 1, time: 1, data: result(),
+      })
+    }).not.toThrow()
+  })
+
+  it.each([
+    [invoked({ point: '' }), /point and handlerId must be non-empty/],
+    [invoked({ handlerId: '' }), /point and handlerId must be non-empty/],
+    [invoked({ dialect: 'other' }), /unknown dialect/],
+  ])('rejects malformed hook invocation %#', async (data, message) => {
+    const ctx = await setup()
+    expect(() => ctx.sessions.create().append('hook/invoked', data as never)).toThrow(message)
+  })
+
+  it('rejects unmatched and malformed results', async () => {
+    const ctx = await setup()
+    const session = ctx.sessions.create()
+    expect(() => session.append('hook/result', result())).toThrow(/no matching hook\/invoked/)
+    session.append('hook/invoked', invoked())
+    expect(() => session.append('hook/result', result({ durationMs: -1 })))
+      .toThrow(/durationMs must be a non-negative finite number/)
+    expect(() => session.append('hook/result', result({ point: 'Stop' })))
+      .toThrow(/no matching hook\/invoked/)
+  })
+})