Add channel-aware release tooling and updater recovery

release_tests/test_channel_settings.py

@@ -0,0 +1,42 @@
+from __future__ import annotations
+
+from pathlib import Path
+import tempfile
+import unittest
+
+from ptlinux.paths import AppPaths
+from ptlinux.settings import Settings, load_settings, save_settings
+
+
+class ChannelSettingsTests(unittest.TestCase):
+	def test_existing_users_default_to_stable(self) -> None:
+		with tempfile.TemporaryDirectory() as temporary:
+			root = Path(temporary)
+			paths = AppPaths(root / "data", root / "config", root / "state", root / "cache")
+			paths.config.mkdir(parents=True)
+			paths.settings_file.write_text('{"realm": "Babel"}\n', encoding="utf-8")
+
+			self.assertEqual(load_settings(paths).update_channel, "stable")
+
+	def test_prerelease_preference_round_trips(self) -> None:
+		with tempfile.TemporaryDirectory() as temporary:
+			root = Path(temporary)
+			paths = AppPaths(root / "data", root / "config", root / "state", root / "cache")
+
+			save_settings(paths, Settings(update_channel="prerelease"))
+
+			self.assertEqual(load_settings(paths).update_channel, "prerelease")
+
+	def test_unknown_channel_is_rejected(self) -> None:
+		with tempfile.TemporaryDirectory() as temporary:
+			root = Path(temporary)
+			paths = AppPaths(root / "data", root / "config", root / "state", root / "cache")
+			paths.config.mkdir(parents=True)
+			paths.settings_file.write_text('{"update_channel": "nightly"}\n', encoding="utf-8")
+
+			with self.assertRaisesRegex(ValueError, "update channel"):
+				load_settings(paths)
+
+
+if __name__ == "__main__":
+	unittest.main()