added motion trajectory simulation

apps/autocal/tests/test_preferences_isolation.py

@@ -0,0 +1,64 @@
+"""Preferences must never be written outside the test scratch directory.
+
+The installed app reads ``apps/autocal/preference.json`` at startup. A test that
+builds a window and closes it saves preferences through ``closeEvent``, so a test
+that forgets to redirect the path rewrites the operator's real settings — which is
+exactly what happened: the finger screen started up pointing at a scratch bundle
+from a previous run and reported it as missing.
+
+``conftest._isolate_preference_file`` is the net. These tests pin it, because a
+fixture that silently stopped applying would look like nothing at all until the app
+was next launched by hand.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+APP_ROOT = Path(__file__).resolve().parents[1]
+INSTALLED = APP_ROOT / "preference.json"
+
+
+def test_the_preference_path_is_redirected_under_the_scratch_root():
+    from orisys_autocal.preferences import path
+
+    resolved = Path(path()).resolve()
+    scratch = (APP_ROOT / "outputs" / "_test_scratch").resolve()
+    assert resolved != INSTALLED.resolve()
+    assert scratch in resolved.parents, resolved
+
+
+def test_saving_preferences_leaves_the_installed_file_alone():
+    from orisys_autocal import preferences as prefs_mod
+
+    before = INSTALLED.read_bytes() if INSTALLED.is_file() else None
+
+    prefs = prefs_mod.default_preferences()
+    prefs["finger_bundle_path"] = str(APP_ROOT / "outputs" / "_test_scratch" / "gone")
+    written = Path(prefs_mod.save_preferences(prefs)).resolve()
+
+    assert written != INSTALLED.resolve()
+    assert written.is_file(), "the save did not reach the redirected file either"
+
+    after = INSTALLED.read_bytes() if INSTALLED.is_file() else None
+    assert after == before, "a test rewrote the installed preference.json"
+
+
+def test_a_window_that_closes_still_lands_in_the_scratch_directory(qt_app):
+    """The failure mode itself: construct, close, check where it wrote."""
+    from orisys_autocal import preferences as prefs_mod
+    from orisys_autocal.ui.window import AutoCalMainWindow
+
+    before = INSTALLED.read_bytes() if INSTALLED.is_file() else None
+
+    prefs = prefs_mod.default_preferences()
+    prefs["finger_bundle_path"] = str(APP_ROOT / "outputs" / "_test_scratch" / "gone")
+    window = AutoCalMainWindow(prefs=prefs, auto_load_bundle=False)
+    try:
+        window.poller.shutdown()
+        window.close()
+    finally:
+        window.poller.shutdown()
+
+    after = INSTALLED.read_bytes() if INSTALLED.is_file() else None
+    assert after == before, "closing a test window rewrote the installed preferences"