refactor(director): surface task and tool changes as reactor events (#1042)

* feat(chat): replace onTasksChange/onActivateTools with reactor events

Hosts subscribe to custom.chat.tasks.changed and custom.chat.tools.activate
on the agent stream; TUI repaints the task panel, exec activates tools.

Fixes CL-7916

* refactor(chat): share reactor event-subscriber helper across sinks (#1054)

Extract the duplicated tasks-changed/tools-activate subscriber blocks into handleChatDirectorEvent, log invalid payloads at debug level instead of dropping them silently, and clear queued task-change notifications when a turn throws.

* chore(deadcode): drop stale usage allowlist, cover eval fixtures

fetchCodexUsage/fetchCodexModels/fetchXaiUsage deleted by #1031;
four completion-harness fixtures loaded by path from script.json.

* chore(deadcode): update keeper test for post-trim allowlist

The CL-6815 trim removed the three usage-formatter exports; the scoped
exemption keeper now pins the two remaining constants flags plus the
negative sibling probe.

Author: TheGreatAxios

scripts/check-dead-exports.test.ts

@@ -28,20 +28,12 @@ import {
 const repoRoot = join(import.meta.dir, "..");
 
 // A probe dead export in one of the scoped files must fail the guard: the
-// exact-name exemptions cover only the five deferred-cleanup flags, never
-// the whole module.
+// exact-name exemptions cover only the remaining deferred-cleanup flags
+// (the usage-formatter flags were removed with their exports by the CL-6815
+// trim), never the whole module.
 describe("scoped exemptions", () => {
   test("the real allowlist covers the named flags but not a sibling probe", () => {
     const rules = loadAllowlist();
-    expect(
-      isAllowlisted(rules, "src/auth/codex/usage.ts", "fetchCodexUsage"),
-    ).toBe(true);
-    expect(
-      isAllowlisted(rules, "src/auth/codex/usage.ts", "fetchCodexModels"),
-    ).toBe(true);
-    expect(isAllowlisted(rules, "src/auth/xai/usage.ts", "fetchXaiUsage")).toBe(
-      true,
-    );
     expect(
       isAllowlisted(
         rules,

scripts/dead-export-allowlist.txt

@@ -26,16 +26,21 @@ vendor/
 # flags so a new dead export in these files fails the guard instead of
 # hiding under a whole-file exemption. Remove each entry with the export it
 # names when the owning cleanup lands.
-src/auth/codex/usage.ts: fetchCodexUsage
-src/auth/codex/usage.ts: fetchCodexModels
-src/auth/xai/usage.ts: fetchXaiUsage
 src/auth/codex/constants.ts: CODEX_REFRESH_SKEW_MS
 src/auth/codex/constants.ts: CODEX_HEADLESS_REFRESH_INTERVAL_MS
 
 # Plugin fixture entry point. Loaded by file path from the fixture's plugin
 # manifest by the plugin-registration tests, so it has no static importers.
 tests/fixtures/plugins/implement-feature/src/index.ts
 
+# Eval completion-harness task fixtures (CL-7932 lane). Loaded by file path
+# from each task's script.json by the harness runner, so they have no static
+# importers.
+evals/completion/tasks/decline-refactor/fixture/notes.ts: addNote
+evals/completion/tasks/stall-read/fixture/data.ts: data
+evals/completion/tasks/sum-fix/fixture/sum.ts: total
+evals/completion/tasks/version-endpoint/fixture/service.ts: handleRequest
+
 # ts-prune parser false positives: bare tokens on `as const satisfies ...`
 # lines inside live exports. None of these is an export declaration.
 src/provider/reasoning-effort.ts: satisfies

src/agent/chat-event-subscribers.test.ts

@@ -0,0 +1,122 @@
+import { describe, expect, test } from "bun:test";
+import {
+  CHAT_TASKS_CHANGED_EVENT,
+  CHAT_TOOLS_ACTIVATE_EVENT,
+} from "./director.js";
+import { handleChatDirectorEvent } from "./chat-event-subscribers.js";
+import type { Task } from "./tasks.js";
+
+function makeLog() {
+  const calls: { message: string; fields?: Record<string, unknown> }[] = [];
+  return {
+    calls,
+    log: (message: string, fields?: Record<string, unknown>): void => {
+      calls.push(fields !== undefined ? { message, fields } : { message });
+    },
+  };
+}
+
+describe("handleChatDirectorEvent", () => {
+  test("dispatches a valid tasks-changed payload without logging", () => {
+    const seen: Task[][] = [];
+    const log = makeLog();
+    const handled = handleChatDirectorEvent(
+      {
+        type: CHAT_TASKS_CHANGED_EVENT,
+        data: { tasks: [{ id: "t1", title: "work", status: "doing" }] },
+      },
+      {
+        onTasksChanged: (tasks) => seen.push(tasks),
+        onToolsActivate: () => {
+          throw new Error("unexpected tools-activate dispatch");
+        },
+      },
+      log.log,
+    );
+    expect(handled).toBe(true);
+    expect(seen).toEqual([[{ id: "t1", title: "work", status: "doing" }]]);
+    expect(log.calls).toEqual([]);
+  });
+
+  test("dispatches a valid tools-activate payload without logging", () => {
+    const seen: string[][] = [];
+    const log = makeLog();
+    const handled = handleChatDirectorEvent(
+      { type: CHAT_TOOLS_ACTIVATE_EVENT, data: { names: ["lsp"] } },
+      {
+        onTasksChanged: () => {
+          throw new Error("unexpected tasks-changed dispatch");
+        },
+        onToolsActivate: (names) => seen.push([...names]),
+      },
+      log.log,
+    );
+    expect(handled).toBe(true);
+    expect(seen).toEqual([["lsp"]]);
+    expect(log.calls).toEqual([]);
+  });
+
+  test("drops an invalid tasks payload with a debug log naming the failure", () => {
+    let dispatched = false;
+    const log = makeLog();
+    const handled = handleChatDirectorEvent(
+      { type: CHAT_TASKS_CHANGED_EVENT, data: { tasks: "not-a-list" } },
+      {
+        onTasksChanged: () => {
+          dispatched = true;
+        },
+        onToolsActivate: () => {
+          dispatched = true;
+        },
+      },
+      log.log,
+    );
+    expect(handled).toBe(true);
+    expect(dispatched).toBe(false);
+    expect(log.calls).toHaveLength(1);
+    expect(log.calls[0]?.message).toMatch(/tasks-changed/);
+    expect(typeof log.calls[0]?.fields?.["error"]).toBe("string");
+  });
+
+  test("drops an invalid tools payload with a debug log naming the failure", () => {
+    let dispatched = false;
+    const log = makeLog();
+    const handled = handleChatDirectorEvent(
+      { type: CHAT_TOOLS_ACTIVATE_EVENT, data: { names: [42] } },
+      {
+        onTasksChanged: () => {
+          dispatched = true;
+        },
+        onToolsActivate: () => {
+          dispatched = true;
+        },
+      },
+      log.log,
+    );
+    expect(handled).toBe(true);
+    expect(dispatched).toBe(false);
+    expect(log.calls).toHaveLength(1);
+    expect(log.calls[0]?.message).toMatch(/tools-activate/);
+    expect(typeof log.calls[0]?.fields?.["error"]).toBe("string");
+  });
+
+  test("ignores unrelated events without logging or dispatching", () => {
+    let dispatched = false;
+    const log = makeLog();
+    const handled = handleChatDirectorEvent(
+      { type: "inference.done", data: {} },
+      {
+        onTasksChanged: () => {
+          dispatched = true;
+        },
+        onToolsActivate: () => {
+          dispatched = true;
+        },
+      },
+      log.log,
+    );
+    expect(handled).toBe(false);
+    expect(dispatched).toBe(false);
+    expect(log.calls).toEqual([]);
+  });
+});

src/agent/chat-event-subscribers.ts

@@ -0,0 +1,62 @@
+/**
+ * Shared subscriber for the chat-director reactor events. The TUI and exec
+ * stream sinks both listen for the task-list and tool-activation events the
+ * chat director emits in place of the former host closures; the parse,
+ * validation, and invalid-payload handling live here so the two sinks cannot
+ * drift apart.
+ */
+
+import { type } from "arktype";
+import {
+  CHAT_TASKS_CHANGED_EVENT,
+  CHAT_TOOLS_ACTIVATE_EVENT,
+  ChatTasksChangedDataSchema,
+  ChatToolsActivateDataSchema,
+} from "./director.js";
+import type { Task } from "./tasks.js";
+
+export interface ChatDirectorEventHandlers {
+  onTasksChanged: (tasks: Task[]) => void;
+  onToolsActivate: (names: string[]) => void;
+}
+
+export type ChatDirectorEventDebugLog = (
+  message: string,
+  fields?: Record<string, unknown>,
+) => void;
+
+/**
+ * Dispatch one stream event to the chat-director handlers. Returns true when
+ * the event is a chat-director event (valid or not) so sinks can fall through
+ * to their own handling otherwise. Invalid payloads are dropped after a
+ * debug-level log naming the failure — never silently.
+ */
+export function handleChatDirectorEvent(
+  event: { type: string; data: unknown },
+  handlers: ChatDirectorEventHandlers,
+  logDebug: ChatDirectorEventDebugLog,
+): boolean {
+  if (event.type === CHAT_TASKS_CHANGED_EVENT) {
+    const parsed = ChatTasksChangedDataSchema(event.data);
+    if (parsed instanceof type.errors) {
+      logDebug("chat tasks-changed event dropped invalid payload: {error}", {
+        error: parsed.summary,
+      });
+      return true;
+    }
+    handlers.onTasksChanged(parsed.tasks);
+    return true;
+  }
+  if (event.type === CHAT_TOOLS_ACTIVATE_EVENT) {
+    const parsed = ChatToolsActivateDataSchema(event.data);
+    if (parsed instanceof type.errors) {
+      logDebug("chat tools-activate event dropped invalid payload: {error}", {
+        error: parsed.summary,
+      });
+      return true;
+    }
+    handlers.onToolsActivate(parsed.names);
+    return true;
+  }
+  return false;
+}