feat(trading): 清空购物车落步骤证据，补空车/有商品两场景测试

- clear_cart 返回清理后 cart 页最终 HTML（best-effort，抓取失败不掩盖清理结果） - runner step 0 落 00-cart-clear.{html,meta.json} 并登记 evidence_index，证据先于闸门判断落盘（清理未净被拦时这份现场就是排查依据）；仍是本机卫生步骤：不上报 gateway、不记 order_events - /api/cart/clear 响应不携带 html（路由显式挑字段，与 cart_add 同风格） - 单测：fake page 覆盖空车/有商品/HTML 抓取失败；runner 层覆盖证据落盘与闸门拦截场景 - 真账号复验 scripts/verify_cart_clear.py：空车 removed=0/count=0；加购 1 件后 clear removed=1/count=0，status 复核 101
2026-08-17 08:32:11 +08:00
parent daa5555fd4
commit 086ab82614
6 changed files with 340 additions and 11 deletions
@@ -13,6 +13,7 @@ evidence store / site，覆盖 §6 主循环的分支：
 from __future__ import annotations

 import asyncio
+import json
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any
@@ -559,6 +560,62 @@ async def test_execute_blocks_when_clear_count_unknown(
    assert "未清空" in terminal["detail"]


+async def test_clear_cart_step_writes_evidence_but_no_gateway_report(
+    runner: WorkerRunner, evidence: EvidenceStore
+):
+    """step 0 落本地证据：清理后的页面 HTML 与 meta.json 在盘上，但不回报 gateway
+
+    clear_cart 返回的 html 是清理结束后的 cart 页现场，meta 记 removed_count /
+    cart_count；它仍是本机卫生步骤——evidence_index 可翻查，gateway 收不到
+    这一步的 evidence_ref。
+    """
+    async def _clear():  # noqa: ANN001
+        return {"removed_count": 1, "cart_count": 0, "html": "<html>cart</html>"}
+
+    async def _noop(task):  # noqa: ANN001
+        return None
+
+    async def _unimplemented(task):  # noqa: ANN001
+        # 流程走到 enter_checkout 为止：step 0 的证据此时已经落盘
+        raise NotImplementedError("模拟：enter_checkout 未实现，到此为止")
+
+    runner._site.clear_cart = _clear  # type: ignore[assignment]
+    runner._site.add_to_cart = _noop  # type: ignore[assignment]
+    runner._site.verify_cart = _noop  # type: ignore[assignment]
+    runner._site.enter_checkout = _unimplemented  # type: ignore[assignment]
+
+    await runner.handle(_make_task(task_id="t1"))
+
+    step_dir = evidence.step_dir("t1")
+    html_text = (step_dir / "00-cart-clear.html").read_text(encoding="utf-8")
+    assert html_text == "<html>cart</html>"
+    meta = json.loads((step_dir / "00-cart-clear.meta.json").read_text(encoding="utf-8"))
+    assert meta == {"step": "cart-clear", "removed_count": 1, "cart_count": 0}
+    # 本机卫生步骤：gateway 的任何 report 都不携带 step-0 的 evidence_ref
+    gateway: FakeGateway = runner._gateway_for_test  # type: ignore[attr-defined]
+    assert all(r["evidence_ref"] != "t1/00-cart-clear" for r in gateway.reports)
+
+
+async def test_clear_cart_evidence_written_when_guard_blocks(
+    runner: WorkerRunner, evidence: EvidenceStore
+):
+    """闸门拦截（清理后 cart_count 非 0）时 step-0 证据同样已落盘
+
+    被拦转 needs_human 时这份现场就是排查依据——证据先于闸门判断落盘。
+    """
+    async def _clear():  # noqa: ANN001
+        return {"removed_count": 2, "cart_count": 2, "html": "<html>leftover</html>"}
+
+    runner._site.clear_cart = _clear  # type: ignore[assignment]
+
+    await runner.handle(_make_task(task_id="t1"))
+
+    step_dir = evidence.step_dir("t1")
+    assert (step_dir / "00-cart-clear.html").exists()
+    meta = json.loads((step_dir / "00-cart-clear.meta.json").read_text(encoding="utf-8"))
+    assert meta["cart_count"] == 2
+
+
 # ---- 证据在 report 之前落盘（§9 第 11 条）----