fix(events): address Codex review — protect post-execute result, purge stale tools/execute refs

Codex's PR-C review found two (A) blockers:

- tools/post-execute could corrupt the protected outcome. postExecute passed the
  mutable `result` to listeners and then read result.callId / spread result on the
  return paths, so a listener mutating the reference (flipping isError, rewriting
  callId, injecting an error) escaped the decision channel. Now the authoritative
  callId/isError/error are SNAPSHOT before the waterfall and the return value is
  rebuilt from the snapshot + the typed PostToolDecision — the decision is the only
  sanctioned way to change the outcome, and callId is always exec.callId. Added a
  regression test that mutates the result reference and asserts it has no effect;
  proven to fail red on the unfixed code.

- Public docs/JSDoc still advertised the removed `tools/execute` waterfall after the
  split. Swept every current-state reference to tools/pre-execute + tools/post-execute:
  the ToolRegistry class JSDoc (and the regenerated catalog), loop.ts's ASCII flow
  (also added the prompt-submit/session-start steps it was missing), the package-map
  READMEs (packages, core, agent-core), core-data-structures core.md/tools.md, the
  bash + acp + invariants src/READMEs (the deferred permission gate is the
  tools/pre-execute deny/ask seam now), the cookbook, and the implemented RFCs whose
  factual seam catalog drifted. codec.ts's totality prose now lists `rejected`.
  Proposed-RFC references are left as-is (frozen proposals, validated when built).
This commit is contained in:
Tianyi Cui
2026-06-30 20:25:30 +08:00
parent dc95a7881d
commit 483e0e5edf
23 changed files with 78 additions and 32 deletions
@@ -66,7 +66,7 @@ The `dsh-tool-subagent` consumer awaits `run.result` and returns the child's fin
## Risks and deferrals
- **Recursion.** Without a guard, an in-process child inherits the spawn tool and can spawn unboundedly. Depth-limit is an optional capability (the in-process backends enforce it; ACP advertises it off and rejects a `maxDepth` request); tool-filtering is likewise optional. Tool-filtering, when implemented, needs a `tools/execute` veto in the child context — schema filtering alone is insufficient because a model can hallucinate a denied tool name.
- **Recursion.** Without a guard, an in-process child inherits the spawn tool and can spawn unboundedly. Depth-limit is an optional capability (the in-process backends enforce it; ACP advertises it off and rejects a `maxDepth` request); tool-filtering is likewise optional. Tool-filtering, when implemented, needs a `tools/pre-execute` deny in the child context — schema filtering alone is insufficient because a model can hallucinate a denied tool name.
- **Blocking the parent turn.** Synchronous collect holds the parent's `runStep` open for the child's full duration. This is acceptable for the first cut; **background / poll / spill semantics are deferred to a future redesign that unifies long-running-tool handling across subagents AND bash** (a sub-agent and a long `bash` background task pose the same "the model started something slow, how does it collect later" problem, and should share one mechanism rather than each inventing its own).
- **Live progress.** This cut surfaces only lifecycle + final result; a per-chunk child→parent update stream is deferred with the background redesign.
- **ACP client surface.** Proxying `fs`/`terminal` from the ACP child back to the parent (a shared-workspace mode) is future work; the first cut advertises neither, so the child self-serves in its own process.