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"""Backup integrity and failure behavior without serial I/O."""
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import json
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from pathlib import Path
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import subprocess
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import tempfile
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import unittest
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from unittest.mock import patch
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import flash_backup as backup
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class BackupTests(unittest.TestCase):
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    def setUp(self):
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        self.temporary = tempfile.TemporaryDirectory()
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        self.addCleanup(self.temporary.cleanup)
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        self.root = Path(self.temporary.name)
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        self.size = patch.object(backup, "FLASH_BYTES", 64)
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        self.size.start()
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        self.addCleanup(self.size.stop)
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    def run_tool(self, command, **kwargs):
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        self.assertTrue(kwargs["check"])
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        self.assertNotIn("write-flash", command)
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        self.assertNotIn("erase-flash", command)
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        if "read-flash" in command:
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            Path(command[-1]).write_bytes(b"x" * 64)
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    def test_verified_image_is_preserved_and_rechecked(self):
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        image = backup.create_backup(self.root, "test-port", self.run_tool)
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        self.assertEqual(backup.require_backup(self.root), image)
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        self.assertEqual(image.stat().st_mode & 0o777, 0o600)
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        record = self.root / backup.RECORD_NAME
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        self.assertEqual(record.stat().st_mode & 0o777, 0o600)
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        self.assertTrue(json.loads(record.read_text())["verified_against_device_flash"])
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        with self.assertRaisesRegex(ValueError, "already exists"):
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            backup.create_backup(self.root, "another-port", lambda *a, **k: self.fail("Must not contact hardware"))
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        image.write_bytes(b"y" * 64)
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        with self.assertRaisesRegex(ValueError, "No valid saved backup"):
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            backup.require_backup(self.root)
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    def test_failed_verification_publishes_no_backup(self):
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        def failing(command, **kwargs):
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            self.run_tool(command, **kwargs)
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            if "verify-flash" in command:
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                raise subprocess.CalledProcessError(1, command)
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        with self.assertRaises(subprocess.CalledProcessError):
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            backup.create_backup(self.root, "test-port", failing)
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        self.assertFalse((self.root / backup.IMAGE_NAME).exists())
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        self.assertFalse((self.root / backup.RECORD_NAME).exists())
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    def test_partial_read_is_not_verified(self):
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        def partial(command, **kwargs):
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            self.assertIn("read-flash", command)
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            Path(command[-1]).write_bytes(b"short")
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        with self.assertRaisesRegex(ValueError, "incomplete"):
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            backup.create_backup(self.root, "test-port", partial)
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        self.assertFalse((self.root / backup.RECORD_NAME).exists())
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    def test_missing_or_malformed_record_is_rejected(self):
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        for contents in [None, "not json", "[]", '{"verified_against_device_flash": true}']:
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            if contents is not None:
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                (self.root / backup.RECORD_NAME).write_text(contents)
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            with self.assertRaisesRegex(ValueError, "No valid saved backup"):
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                backup.require_backup(self.root)
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if __name__ == "__main__":
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    unittest.main()