fix(memory-tool): compare resolved path rather than raw string in delete root guard

[agarwal-tanmay-work]

Summary

In BetaLocalFilesystemMemoryTool and BetaAsyncLocalFilesystemMemoryTool, the delete() method prevents deletion of the root directory using an exact string check (if command.path == "/memories":).

Because _validate_path resolves trailing slash and relative dot variations (such as /memories/ or /memories/.) to self.memory_root, these variants bypass the raw string check and cause the root memory directory to be deleted via shutil.rmtree().

Changes

• Updated sync delete() to check if full_path == self.memory_root.resolve():
• Updated async delete() to check if full_path == await self.memory_root.resolve():
• Updated unit tests in test_filesystem.py to parametrize and assert that /memories, /memories/, and /memories/. are all rejected.

[chrikrah]

@agarwal-tanmay-work on 4421d56 the bare /memories raises, while /memories/, /memories/. and /memories/./ each delete the store and the files under it. On a822890 all four raise. Approve.

non-blocking: /memories/sub/.. is a live bypass on the base too, and a822890 already catches it, but the parametrize list stops at /memories/.. #1906 parametrizes /memories/subdir/.. already, so that entry is worth copying here only if this branch lands first.

#1906 by @Kayvan-Zahiri changes the same two guards and the rename guard as well, and #1914 changes the /memories prefix check in the same file.

Verification

Two clean exports, a822890 and the same tree with src/anthropic/lib/tools/_beta_builtin_memory_tool.py rolled back to 4421d56. uv sync --all-extras in each, anthropic.__file__ asserted inside the export.

$ uv run pytest tests/lib/tools/memory_tools -q -p no:randomly
73 passed in 6.84s

# rolled-back source, the new tests kept
$ uv run pytest tests/lib/tools/memory_tools -q -p no:randomly
4 failed, 69 passed in 6.32s
E   Failed: DID NOT RAISE <class 'anthropic.lib.tools._beta_functions.ToolError'>

# BetaLocalFilesystemMemoryTool.delete over six spellings, rolled-back source
$ uv run python probe.py
'/memories'          -> ToolError; memories/ exists=True
'/memories/'         -> no error; memories/ exists=False; keep.txt exists=False
'/memories/.'        -> no error; memories/ exists=False; keep.txt exists=False
'/memories/sub/..'   -> no error; memories/ exists=False; keep.txt exists=False
'/memories/./'       -> no error; memories/ exists=False; keep.txt exists=False
'//memories'         -> ToolError 'Path must start with /memories'; memories/ exists=True

# same probe on a822890
$ uv run python probe.py
'/memories'          -> ToolError Cannot delete the /memories directory itself; memories/ exists=True; keep.txt exists=True
'/memories/'         -> ToolError Cannot delete the /memories directory itself; memories/ exists=True; keep.txt exists=True
'/memories/.'        -> ToolError Cannot delete the /memories directory itself; memories/ exists=True; keep.txt exists=True
'/memories/sub/..'   -> ToolError Cannot delete the /memories directory itself; memories/ exists=True; keep.txt exists=True
'/memories/./'       -> ToolError Cannot delete the /memories directory itself; memories/ exists=True; keep.txt exists=True
'//memories'         -> ToolError Path must start with /memories, got: //memories; memories/ exists=True; keep.txt exists=True
# not run: anything outside tests/lib/tools, and any run on Windows

@dtmeadows-ant two open branches fix this delete guard, this one and #1906, and only you can say which should carry it. Which do you want @agarwal-tanmay-work and @Kayvan-Zahiri to build on?

[agarwal-tanmay-work]

Thanks @chrikrah for the thorough verification and approval!

I've pushed an update adding both /memories/./ and /memories/sub/.. to the test parametrizations (for both sync and async) so test coverage explicitly verifies those paths as well.

@dtmeadows-ant — happy to defer to your preference here. If you prefer to land this focused fix on the delete guard, it's ready. If you'd rather consolidate or have this build on/alongside @Kayvan-Zahiri's #1906 (or add the rename guard here as well), just let me know and I'm glad to adjust.

[chrikrah]

@agarwal-tanmay-work still an approve at be88869. The two spellings you added fail on the old guard, so all four that got through on 4421d56 are now pinned, sync and async.

# Python 3.12.3, pytest 9.1.1, tree from git archive be88869
$ PYTHONPATH=$HEAD/src python -m pytest tests/lib/tools/memory_tools -q -p no:randomly \
    -o addopts="--tb=line -p tests._alias_httpx"
77 passed in 4.07s

# _beta_builtin_memory_tool.py from 4421d56, tests kept
8 failed, 69 passed in 3.83s
E   Failed: DID NOT RAISE ToolError
FAILED ...TestBetaLocalFilesystemMemoryTool::test_delete_not_allow_deleting_memories_directory[/memories/./]
FAILED ...TestBetaLocalFilesystemMemoryTool::test_delete_not_allow_deleting_memories_directory[/memories/sub/..]
# the other six: /memories/ and /memories/. in this class, all four in the async class

Nothing more from me on this branch. If the guard moves again once the #1906 question is settled, I will rerun these eight cases on the new head.