init

backend/tests/test_kanban.py

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+"""Engine tests with fake processors (no LLM): flow, barrier, retry/dead-letter, producer race."""
+
+import asyncio
+
+import pytest
+
+import kanban
+from kanban import Flow, Stage, chain_stages, run_flow
+
+TOPIC = "t"
+BOARD = "inventory"
+
+
+def _advance_proc(db, to_stage):
+    async def proc(cards):
+        await db.kanban_advance_many(TOPIC, BOARD, [(c["card_id"], to_stage) for c in cards])
+    return proc
+
+
+async def _seed(db, n, stage="s1"):
+    for i in range(n):
+        await db.kanban_upsert_card(TOPIC, BOARD, f"card-{i}", "title", stage, {"title": f"T{i}"})
+
+
+async def test_cards_flow_through_stages(testdb):
+    db = testdb
+    await _seed(db, 7)
+    flow = Flow(TOPIC)
+    stages = chain_stages([
+        Stage(BOARD, "s1", _advance_proc(db, "s2")),
+        Stage(BOARD, "s2", _advance_proc(db, "done")),
+    ])
+    await asyncio.wait_for(run_flow(flow, stages), timeout=10)
+    assert await db.kanban_count(TOPIC, "done", board=BOARD) == 7
+    assert await db.kanban_count(TOPIC, ["s1", "s2"], board=BOARD) == 0
+
+
+async def test_barrier_waits_for_upstream(testdb):
+    db = testdb
+    await _seed(db, 6)
+    upstream_left: list[int] = []
+
+    async def slow_s1(cards):
+        await asyncio.sleep(0.05)  # keep upstream busy so an eager barrier would see queued cards
+        await db.kanban_advance_many(TOPIC, BOARD, [(c["card_id"], "gate") for c in cards])
+
+    async def barrier_proc(cards):
+        upstream_left.append(await db.kanban_count(TOPIC, ["s1"], board=BOARD))
+        await db.kanban_advance_many(TOPIC, BOARD, [(c["card_id"], "done") for c in cards])
+
+    flow = Flow(TOPIC)
+    stages = chain_stages([
+        Stage(BOARD, "s1", slow_s1),
+        Stage(BOARD, "gate", barrier_proc, barrier=True),
+    ])
+    await asyncio.wait_for(run_flow(flow, stages), timeout=10)
+    assert await db.kanban_count(TOPIC, "done", board=BOARD) == 6
+    assert upstream_left and all(n == 0 for n in upstream_left)  # barrier never ran with s1 queued
+
+
+async def test_retry_backoff_then_dead(testdb, monkeypatch):
+    db = testdb
+    monkeypatch.setattr(kanban, "RETRY_BACKOFF", 0.02)
+    await _seed(db, 1)
+    attempts = []
+
+    async def failing(cards):
+        attempts.append(cards[0]["retries"])
+        raise RuntimeError("kaputt")
+
+    flow = Flow(TOPIC)
+    stages = chain_stages([Stage(BOARD, "s1", failing)])
+    await asyncio.wait_for(run_flow(flow, stages), timeout=10)
+    card = await db.kanban_get_card(TOPIC, BOARD, "card-0")
+    assert card["stage"] == "dead"
+    assert card["retries"] == kanban.MAX_CARD_RETRIES
+    assert "kaputt" in card["last_error"]
+    assert attempts == [0, 1, 2]  # backoff between attempts, then dead-letter
+
+
+async def test_requeue_dead(testdb):
+    db = testdb
+    await db.kanban_upsert_card(TOPIC, BOARD, "card-0", "title", "s1")
+    for _ in range(kanban.MAX_CARD_RETRIES):
+        await db.kanban_fail_card(TOPIC, BOARD, "card-0", "x", kanban.MAX_CARD_RETRIES, 0.0)
+    assert (await db.kanban_get_card(TOPIC, BOARD, "card-0"))["stage"] == "dead"
+    assert await db.kanban_requeue_dead(TOPIC, BOARD, "s1") == 1
+    card = await db.kanban_get_card(TOPIC, BOARD, "card-0")
+    assert card["stage"] == "s1" and card["retries"] == 0
+
+
+async def test_producer_attach_in_idle_lull(testdb):
+    """Fix-6 regression: a producer attached while workers sit in the exit grace poll
+    must keep the flow alive and its cards must still be processed."""
+    db = testdb
+    flow = Flow(TOPIC)
+    stages = chain_stages([Stage(BOARD, "s1", _advance_proc(db, "done"))])
+
+    async def producer_a():
+        await db.kanban_upsert_card(TOPIC, BOARD, "card-a", "title", "s1")
+        flow.wake.set()
+        flow.done_producer()
+
+    async def attacher():
+        while await db.kanban_count(TOPIC, "done", board=BOARD) == 0:  # wait for card-a done
+            await asyncio.sleep(0.01)
+        flow.add_producer()  # synchronous BEFORE the work — the grace poll must see it
+
+        async def producer_b():
+            await db.kanban_upsert_card(TOPIC, BOARD, "card-b", "title", "s1")
+            flow.wake.set()
+            flow.done_producer()
+        await producer_b()
+
+    flow.add_producer()  # producer_a, counted before run_flow (sync add)
+    asyncio.get_event_loop().create_task(attacher())
+    await asyncio.wait_for(run_flow(flow, stages, producers=[producer_a()]), timeout=10)
+    assert await db.kanban_count(TOPIC, "done", board=BOARD) == 2
+
+
+async def test_backoff_delays_pull(testdb, monkeypatch):
+    db = testdb
+    await db.kanban_upsert_card(TOPIC, BOARD, "card-0", "title", "s1")
+    await db.kanban_fail_card(TOPIC, BOARD, "card-0", "x", 5, 0.2)
+    assert await db.kanban_pull(TOPIC, BOARD, "s1", 10) == []   # in backoff → not pullable
+    assert await db.kanban_count(TOPIC, "s1", board=BOARD) == 1  # but still counts as queued
+    await asyncio.sleep(0.25)
+    assert len(await db.kanban_pull(TOPIC, BOARD, "s1", 10)) == 1