MediumEditing SystemsPython 3
Patch Conflict Detector
Apply optimistic multi-file patches atomically while rejecting stale or overlapping edits.
40m2 sample tests5 hidden tests
Implement apply_patches(files, patches), an atomic patch applier with optimistic conflict checks.
Requirements
filesmaps file path to text.- Each patch is
(path, start, end, expected_old_text, replacement). - Validate all patches before mutating anything.
- Reject invalid ranges, missing files, overlapping patches in the same file, and expected-text mismatches.
- Apply patches from the end of each file so offsets stay stable.
- Return a new dictionary and leave input untouched.
Example
python
1files = {"app.py": "print('old')\n"}
2patches = [("app.py", 6, 11, "'old'", "'new'")]
3assert apply_patches(files, patches)["app.py"] == "print('new')\n"Constraints
- No diff parser is required.
- Treat offsets as Python string indexes.
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