sched: extract typed preparer/dispatcher seams; test impl out of production (F6)

tests/scheduling/test_poll.py

@@ -4,12 +4,19 @@ from __future__ import annotations
 
 from datetime import UTC, datetime, timedelta
 from pathlib import Path
-from typing import Any
+from typing import Any, cast
 
+from tests.scheduling.controlled import (
+    DictDeployments,
+    ScriptedDispatcher,
+    fixture_environment,
+)
 from wf_artifacts.runs.models import StoredRunStatus
 from wf_artifacts.runs.store import FileRunStore
+from wf_scheduling.calendar import OneShotSource
 from wf_scheduling.models import Schedule
 from wf_scheduling.poll import SCAN_CAP, Scheduler
+from wf_scheduling.prepare import SchedulePreparer
 from wf_scheduling.store import FileScheduleStore
 
 UTC_TZ = UTC
@@ -41,21 +48,6 @@ class PeriodicSource:
         return self.start + n * self.period
 
 
-class OneShotSource:
-    def __init__(self, at: datetime) -> None:
-        self.at = at
-        self.next_calls = 0
-        self.prev_calls = 0
-
-    def next_after(self, instant: datetime) -> datetime | None:
-        self.next_calls += 1
-        return self.at if instant < self.at else None
-
-    def prev_before(self, instant: datetime) -> datetime | None:
-        self.prev_calls += 1
-        return self.at if instant > self.at else None
-
-
 def _sched_model(sid: str, start_hint: str = "cron", **kw: Any) -> Schedule:
     now = ts(2026, 9, 8, 12, 0)
     base: dict[str, Any] = {
@@ -74,21 +66,27 @@ def _harness(
     tmp_path: Path,
     *,
     capacity: int = 4,
-    outcomes: dict[str, str] | None = None,
+    script: dict | None = None,
     deployments: dict[str, dict] | None = None,
 ) -> tuple[Scheduler, FileScheduleStore, FileRunStore, dict]:
     sched_store = FileScheduleStore(tmp_path / "sched")
     run_store = FileRunStore(tmp_path / "runs")
     sources: dict = {}
+    preparer = SchedulePreparer(
+        DictDeployments(
+            deployments
+            if deployments is not None
+            else {"dep-1": {"rev": 1, "required": []}}
+        ),
+        fixture_environment,
+    )
     sched = Scheduler(
         schedule_store=sched_store,
         run_store=run_store,
         sources=sources,
         capacity=capacity,
-        outcomes=outcomes,
-        deployments=deployments
-        if deployments is not None
-        else {"dep-1": {"rev": 1, "required": []}},
+        preparer=preparer,
+        dispatcher=ScriptedDispatcher(script),
     )
     return sched, sched_store, run_store, sources
 
@@ -119,7 +117,7 @@ def test_overlap_skip_blocks_and_late_drops() -> None:
 
     with tempfile.TemporaryDirectory() as tmp:
         root = Path(tmp)
-        sched, store, runs, sources = _harness(root, capacity=4, outcomes={"*": "hang"})
+        sched, store, runs, sources = _harness(root, capacity=4, script={"*": "hang"})
         t0 = ts(2026, 9, 8, 12, 0)
         _add(
             sched,
@@ -161,7 +159,7 @@ def test_latest_coalesces_to_one_candidate_and_no_double_admit() -> None:
         # Capacity returns at 13:00 while 13:00 is also due: exactly one
         # admission for 13:00, 12:00 superseded, never both.
         sched.capacity = 4
-        sched.outcomes = {"*": "complete"}
+        cast(ScriptedDispatcher, sched.dispatcher).script = {"*": "complete"}
         sched.poll(ts(2026, 9, 8, 13, 0))
         admitted = [r for r in _history(store, "h") if r["kind"] == "admitted"]
         assert len(admitted) == 1
@@ -176,7 +174,7 @@ def test_parallel_limits_and_interrupted_slots() -> None:
 
     with tempfile.TemporaryDirectory() as tmp:
         root = Path(tmp)
-        sched, store, runs, sources = _harness(root, capacity=4, outcomes={"*": "hang"})
+        sched, store, runs, sources = _harness(root, capacity=4, script={"*": "hang"})
         t0 = ts(2026, 9, 8, 12, 0)
         _add(
             sched,
@@ -216,7 +214,7 @@ def test_pause_is_not_downtime() -> None:
     with tempfile.TemporaryDirectory() as tmp:
         root = Path(tmp)
         sched, store, runs, sources = _harness(
-            root, capacity=4, outcomes={"*": "complete"}
+            root, capacity=4, script={"*": "complete"}
         )
         _add(
             sched,
@@ -244,7 +242,7 @@ def test_pause_is_not_downtime() -> None:
 
 def test_long_downtime_is_bounded(tmp_path: Path) -> None:
     sched, store, runs, sources = _harness(
-        tmp_path, capacity=4, outcomes={"*": "complete"}
+        tmp_path, capacity=4, script={"*": "complete"}
     )
     src = PeriodicSource(timedelta(minutes=1), ts(2023, 9, 8, 12, 0))
     _add(sched, store, sources, "m", src, ts(2023, 9, 8, 12, 0), misfire="latest")
@@ -259,7 +257,7 @@ def test_long_downtime_is_bounded(tmp_path: Path) -> None:
 
 
 def test_fairness_slow_schedule_not_starved(tmp_path: Path) -> None:
-    sched, store, runs, sources = _harness(tmp_path, capacity=1, outcomes={"*": "hang"})
+    sched, store, runs, sources = _harness(tmp_path, capacity=1, script={"*": "hang"})
     t0 = ts(2026, 9, 8, 12, 0)
     _add(
         sched,
@@ -288,6 +286,6 @@ def test_capacity_wait_then_expire_for_skip(tmp_path: Path) -> None:
     assert sched.poll(t0) == {"a": "admit:held-undecided"}
     assert store.get_candidate("a") is None
     sched.capacity = 1
-    sched.outcomes = {"*": "complete"}
+    cast(ScriptedDispatcher, sched.dispatcher).script = {"*": "complete"}
     sched.poll(t0 + timedelta(seconds=30))
     assert len([r for r in _history(store, "a") if r["kind"] == "admitted"]) == 1