fix(workspace): skip idle prompt when delegation results are pending

Issue #381: the idle loop fired every idle_interval_seconds (default 10 min)
and sent the idle prompt even when delegation results were pending. The
heartbeat sends a self-message to notify the agent when results arrive, but
the idle prompt could arrive first, causing the agent to compose a stale tick
before processing the pending delegation notification.

Fix: before sending the idle prompt, read _DELEGATION_RESULTS_FILE. If the
file exists and is non-empty, skip this idle tick and log why. The heartbeat
will notify the agent when it next runs and sees the pending results.

Added test_idle_loop_pending_check.py covering: no file, empty file,
whitespace-only, single result, multiple results, newline-only.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

workspace/main.py

@@ -668,6 +668,31 @@ async def main():  # pragma: no cover
                 if heartbeat.active_tasks > 0:
                     continue
 
+                # Issue #381 fix: skip the idle prompt if there are unconsumed
+                # delegation results waiting. The heartbeat sends a self-message
+                # for every new result batch, so sending the idle prompt here would
+                # race: the agent would compose a stale tick BEFORE processing the
+                # results notification, producing repeated identical asks (peer sends
+                # correction, we respond with stale state, peer asks again).
+                # By skipping the idle prompt when results are pending, we let the
+                # heartbeat's own self-message wake the agent after results are
+                # written. The agent then sees the results in _prepare_prompt()
+                # and processes them before composing.
+                from heartbeat import DELEGATION_RESULTS_FILE as _DRF
+                try:
+                    with open(_DRF) as _rf:
+                        _rf.seek(0)
+                        _content = _rf.read().strip()
+                    if _content:
+                        print(
+                            f"Idle loop: skipping — {len(_content)} bytes of unconsumed "
+                            f"delegation results pending (heartbeat will notify agent)",
+                            flush=True,
+                        )
+                        continue
+                except FileNotFoundError:
+                    pass  # No results file — normal, proceed with idle prompt
+
                 # Self-post the idle prompt via the platform A2A proxy (same
                 # path as initial_prompt). The agent's own concurrency control
                 # rejects if the workspace becomes busy between this check and

workspace/tests/test_idle_loop_pending_check.py

@@ -0,0 +1,80 @@
+"""Tests for issue #381: idle loop must not fire when delegation results are pending.
+
+The idle loop skips sending the idle prompt when DELEGATION_RESULTS_FILE
+contains unconsumed results, preventing the agent from composing a stale tick
+before processing pending delegation notifications from the heartbeat.
+
+Source: workspace/main.py:_run_idle_loop() pending-results guard.
+"""
+from __future__ import annotations
+
+import json
+
+import pytest
+
+
+def check_results_pending(file_path: str) -> bool:
+    """Mirror the guard logic from workspace/main.py:_run_idle_loop().
+
+    Returns True if the results file exists and is non-empty,
+    meaning the idle loop should skip this tick.
+    """
+    try:
+        with open(file_path) as rf:
+            rf.seek(0)
+            content = rf.read().strip()
+        return bool(content)
+    except FileNotFoundError:
+        return False
+
+
+class TestIdleLoopPendingCheck:
+    """Tests for the idle-loop pending-delegation-results guard."""
+
+    def test_no_file_means_proceed(self, tmp_path):
+        """No delegation results file → idle loop fires normally."""
+        results_file = tmp_path / "delegation_results.jsonl"
+        assert not check_results_pending(str(results_file))
+
+    def test_empty_file_means_proceed(self, tmp_path):
+        """Empty file → no pending results → idle loop fires."""
+        results_file = tmp_path / "delegation_results.jsonl"
+        results_file.write_text("", encoding="utf-8")
+        assert not check_results_pending(str(results_file))
+
+    def test_whitespace_only_file_means_proceed(self, tmp_path):
+        """File with only whitespace → treated as empty → idle loop fires."""
+        results_file = tmp_path / "delegation_results.jsonl"
+        results_file.write_text("  \n  ", encoding="utf-8")
+        assert not check_results_pending(str(results_file))
+
+    def test_single_result_means_skip(self, tmp_path):
+        """File with one delegation result → skip idle tick."""
+        results_file = tmp_path / "delegation_results.jsonl"
+        results_file.write_text(
+            json.dumps({
+                "status": "completed",
+                "delegation_id": "del-abc",
+                "summary": "Done",
+            }) + "\n",
+            encoding="utf-8",
+        )
+        assert check_results_pending(str(results_file))
+
+    def test_multiple_results_means_skip(self, tmp_path):
+        """File with multiple delegation results → skip idle tick."""
+        results_file = tmp_path / "delegation_results.jsonl"
+        results_file.write_text(
+            json.dumps({"status": "completed", "delegation_id": "del-1", "summary": "A"})
+            + "\n"
+            + json.dumps({"status": "failed", "delegation_id": "del-2", "summary": "B"})
+            + "\n",
+            encoding="utf-8",
+        )
+        assert check_results_pending(str(results_file))
+
+    def test_file_with_only_newline_means_proceed(self, tmp_path):
+        """File with only a newline character → stripped to empty → fires."""
+        results_file = tmp_path / "delegation_results.jsonl"
+        results_file.write_text("\n", encoding="utf-8")
+        assert not check_results_pending(str(results_file))