Isolate pytest env per file so fail-closed and setup stay script-accurate.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitea/workflows/test.yml

@@ -54,7 +54,10 @@ jobs:
             -e PYTHONUTF8=1 \
             backend sh -lc '
               set -e
-              unset KANSHO_DB_PATH
+              unset KANSHO_DB_PATH KANSHO_FAKE_PROVIDER KANSHO_FAKE_DETECT
+              unset KANSHO_PROVIDER_KEY KANSHO_DETECT_PROVIDER_KEY
+              export KANSHO_PROVIDER_KEY=
+              export KANSHO_DETECT_PROVIDER_KEY=
               pip install -q -r requirements-dev.txt
               python -m pytest tests -m "not slow" -ra -vv --tb=short
             '

backend/tests/conftest.py

@@ -2,7 +2,8 @@
 
 Each file stays one case (`main()`) until it is split into native pytest
 functions. Integration files reset `kansho_test` only; `kansho_dev` is never
-the test target.
+the test target. Provider keys and fake flags are restored per file so the
+shared pytest process matches the old one-script-per-process isolation.
 """
 from __future__ import annotations
 
@@ -17,6 +18,7 @@ if str(ROOT) not in sys.path:
     sys.path.insert(0, str(ROOT))
 
 from tests.harness import (  # noqa: E402
+    apply_module_env,
     is_postgres_test_database,
     prepare_test_env,
     reset_postgres_schema,
@@ -56,34 +58,32 @@ def pytest_collection_modifyitems(config: pytest.Config, items: list[pytest.Item
 class KanshoScriptModule(pytest.Module):
     def collect(self):
         module = self.obj
-
-        def test_main() -> None:
-            main = getattr(module, "main", None)
-            if main is None or not callable(main):
-                pytest.fail(f"{self.path.name} has no callable main()")
-            main()
-
-        yield pytest.Function.from_parent(self, name="test_main", callobj=test_main)
+        main = getattr(module, "main", None)
+        if main is None or not callable(main):
+            pytest.fail(f"{self.path.name} has no callable main()")
+        yield pytest.Function.from_parent(self, name="test_main", callobj=main)
 
 
 @pytest.fixture(scope="module", autouse=True)
 def _module_backend(request: pytest.FixtureRequest):
-    stem = Path(str(request.path)).stem
-    if stem in UNIT_MODULES:
-        saved = dict(os.environ)
-        try:
+    source = Path(str(request.path))
+    stem = source.stem
+    saved = dict(os.environ)
+    try:
+        apply_module_env(source)
+        if stem in UNIT_MODULES:
             yield
-        finally:
-            os.environ.clear()
-            os.environ.update(saved)
-        return
-    if not is_postgres_test_database():
-        pytest.skip(
-            "integration requires KANSHO_DB_BACKEND=postgres and DB_NAME ending _test "
-            "(Gitea: kansho_test on the Dev Postgres, never kansho_dev)"
-        )
-    reset_postgres_schema()
-    from db import init_db
+            return
+        if not is_postgres_test_database():
+            pytest.skip(
+                "integration requires KANSHO_DB_BACKEND=postgres and DB_NAME ending _test "
+                "(Gitea: kansho_test on the Dev Postgres, never kansho_dev)"
+            )
+        reset_postgres_schema()
+        from db import init_db
 
-    init_db()
-    yield
+        init_db()
+        yield
+    finally:
+        os.environ.clear()
+        os.environ.update(saved)

backend/tests/harness.py

@@ -39,9 +39,28 @@ def is_postgres_test_database() -> bool:
 
 
 def prepare_test_env() -> None:
-    os.environ.setdefault("KANSHO_PROVIDER_KEY", "")
-    os.environ.setdefault("KANSHO_DETECT_PROVIDER_KEY", "")
+    """Fail-closed defaults. Do not keep Compose provider keys or leftover fakes."""
+    os.environ["KANSHO_PROVIDER_KEY"] = ""
+    os.environ["KANSHO_DETECT_PROVIDER_KEY"] = ""
     os.environ.pop("KANSHO_DB_PATH", None)
+    os.environ.pop("KANSHO_FAKE_PROVIDER", None)
+    os.environ.pop("KANSHO_FAKE_DETECT", None)
+
+
+def apply_module_env(source) -> None:
+    """Restore per-file env so pytest does not leak fakes/keys across scripts."""
+    from pathlib import Path
+
+    prepare_test_env()
+    text = Path(source).read_text(encoding="utf-8")
+    if 'os.environ["KANSHO_FAKE_PROVIDER"] = "1"' in text or "os.environ['KANSHO_FAKE_PROVIDER'] = '1'" in text:
+        os.environ["KANSHO_FAKE_PROVIDER"] = "1"
+    if (
+        'os.environ["KANSHO_FAKE_DETECT"] = "1"' in text
+        or "os.environ['KANSHO_FAKE_DETECT'] = '1'" in text
+        or 'os.environ.setdefault("KANSHO_FAKE_DETECT", "1")' in text
+    ):
+        os.environ["KANSHO_FAKE_DETECT"] = "1"
 
 
 def _require_test_database() -> None:

backend/tests/test_journal_style_context.py

@@ -209,6 +209,9 @@ def main() -> None:
     test_compile_flags()
     test_budget_omission_in_effective_trace()
 
+    from tests.harness import reset_postgres_schema
+
+    reset_postgres_schema()
     init_db()
     reset_debug()
     with TestClient(app) as client:

backend/tests/test_journal_style_legacy_immutable.py

@@ -268,6 +268,9 @@ def test_later_semantic_seed_creates_successor() -> None:
 
 
 def test_legacy_generate_trace_and_prompt() -> None:
+    from tests.harness import reset_postgres_schema
+
+    reset_postgres_schema()
     init_db()
     client = TestClient(app)
     setup = client.post(