bench-suite: hand the watch case a Natives

packages/python/e2e-attestations/bot-1503-bench-watch-1011.json

@@ -0,0 +1,7 @@
+{
+  "command": "uv run python -m tests.e2e.bench_suite --pairs 5 --out /tmp/bench-1503 -k watch",
+  "ran_at": 1791769095,
+  "exit_code": 0,
+  "commit": "409ebb5a7e1da55d1516983fcd936cae7fdc952c",
+  "branch": "bot/1503-bench-watch-1011"
+}

packages/python/tests/e2e/watch_speed_test.py

@@ -23,6 +23,7 @@
 import pytest
 
 from .speed_of_light import (
+    Natives,
     Startup,
     assert_speed_of_light,
     cli,
@@ -147,6 +148,11 @@ def close(self):
         self.proc.wait(timeout=60)
 
 
+def measure(native, dirsql):
+    natives = Natives({"inotifywait": native.sample}, [])
+    return paired(natives, lambda _timeout: dirsql.sample(), NO_STARTUP, PAIRS)
+
+
 def describe_watch_speed_of_light():
     @pytest.fixture(scope="module")
     def trees(tmp_path_factory):
@@ -165,9 +171,7 @@ def trees(tmp_path_factory):
 
     def it_delivers_a_write_to_the_consumer_within_the_bar(trees):
         native, dirsql = trees
-        result = paired(
-            native.sample, lambda _timeout: dirsql.sample(), NO_STARTUP, PAIRS
-        )
-        assert result.native_rows == next(native.writer.samples) - 1
+        result = measure(native, dirsql)
+        assert result.native_rows == {"inotifywait": next(native.writer.samples) - 1}
         assert result.dirsql_rows == next(dirsql.writer.samples) - 1
         assert_speed_of_light("watch", result, NO_STARTUP)

packages/python/tests/integration/hermetic/watch_speed_case_test.py

@@ -0,0 +1,39 @@
+"""Hermetic test that the watch case hands the harness a well-formed native."""
+
+import os
+from itertools import count
+from unittest.mock import patch
+
+import pytest
+
+from tests.e2e.watch_speed_test import measure
+
+
+class Side:
+    def __init__(self, seconds):
+        self.seconds = seconds
+        self.samples = count(1)
+        self.last = 0
+
+    def sample(self):
+        self.last = next(self.samples)
+        return self.last, self.seconds
+
+
+@pytest.fixture(params=[False, True], ids=["ratchet", "suite"])
+def mode(request):
+    env = {"DIRSQL_BENCH_PAIRS": "", "DIRSQL_BENCH_OUT": ""}
+    if request.param:
+        env = {"DIRSQL_BENCH_PAIRS": "3", "DIRSQL_BENCH_OUT": "/tmp/unused"}
+    with patch.dict(os.environ, env):
+        yield
+
+
+def describe_measure():
+    def it_pairs_the_watcher_with_dirsql(mode):
+        native, dirsql = Side(1.0), Side(1.0)
+        result = measure(native, dirsql)
+        assert list(result.native_seconds) == ["inotifywait"]
+        assert result.native_rows == {"inotifywait": native.last}
+        assert result.dirsql_rows == dirsql.last
+        assert result.bar == "inotifywait"