Audit 008 — Package Bugs (User-Facing)¶

Date: 2026-04-02 Scope: All source code under src/remote_store/ — core store, backends, extensions, async API, configuration. Method: Systematic code review of all 52 source files, followed by executable reproduction scripts for each candidate bug. Only findings with confirmed failing reproductions are included.

Summary¶

ID	Component	Severity	Title
B-1	`ext/cache`	High	CachedStore: write doesn't invalidate parent directory metadata
B-2	`ext/cache`	High	CachedStore.child() creates isolated cache — cross-store coherence lost
B-3	`_config`	Medium	`RegistryConfig.from_dict` crashes on YAML/TOML `null` options
B-4	`_config`	Medium	`RegistryConfig.from_dict` silently converts `null` to string `"None"`
B-5	`ext/partition`	Low	`partition_path` allows `=` in key — round-trip with `parse_partition` fails

B-1 — CachedStore: write doesn't invalidate parent directory metadata¶

File: src/remote_store/ext/cache.py lines 288–292 (_invalidate_path) Severity: High

Description¶

When writing a file at a nested path (e.g. dir/file.txt), the backend implicitly creates intermediate directories. CachedStore._invalidate_path only invalidates cache entries for the exact path written, not for any parent directories. This leaves exists(), is_file(), and is_folder() cache entries for parent paths stale.

Reproduction¶

from remote_store.backends._memory import MemoryBackend
from remote_store._store import Store
from remote_store.ext.cache import cache

store = Store(MemoryBackend())
cached = cache(store, ttl=300)

# Cache "newdir" as non-existent
assert cached.exists("newdir") == False       # cached

# Write creates "newdir" implicitly
cached.write("newdir/file.txt", b"hello", overwrite=True)

# BUG: returns stale False — should be True
assert cached.exists("newdir") == False        # stale!
assert store.exists("newdir") == True          # actual truth

Execution result¶

exists("newdir") before write: False
exists("newdir") after write:  False    ← stale
is_folder("newdir") after write: False  ← stale

Root cause¶

_invalidate_path(path) at line 288 iterates _PATH_PREFIXES and deletes (prefix, path) — only the leaf path — then calls _invalidate_listings() (line 292), which clears all listing/glob cache entries. Listing operations like list_files("newdir") therefore return fresh results. However, per-path metadata (exists, is_folder, is_file) for parent segments (e.g. "newdir" when writing "newdir/file.txt") is not invalidated.

B-2 — CachedStore.child() creates isolated cache¶

File: src/remote_store/ext/cache.py lines 443–451 (_wrap_child) Severity: High

Description¶

CachedStore._wrap_child() creates a new CachedStore with cache_backend=None, meaning a fresh MemoryCache. The child and parent have completely independent caches. Writing through the child does not invalidate the parent's cached entries, so the parent returns stale data.

Reproduction¶

from remote_store.backends._memory import MemoryBackend
from remote_store._store import Store
from remote_store.ext.cache import cache

store = Store(MemoryBackend())
cached_store = cache(store, ttl=300)

cached_store.write("sub/file.txt", b"version1", overwrite=True)
content1 = cached_store.read_bytes("sub/file.txt")  # cached

child = cached_store.child("sub")
child.write("file.txt", b"version2", overwrite=True)  # child cache only

# BUG: parent returns stale cached content
content2 = cached_store.read_bytes("sub/file.txt")
assert content2 == b"version1"                  # stale!
assert store.read_bytes("sub/file.txt") == b"version2"  # truth

Execution result¶

Parent reads:                   b'version1'
Parent reads after child write: b'version1'   ← stale
Actual value in store:          b'version2'

Root cause¶

_wrap_child at line 444 passes cache_backend=None, which triggers MemoryCache() construction at line 240. The parent's cache instance is never shared or linked.

B-3 — RegistryConfig.from_dict crashes on YAML/TOML null options¶

File: src/remote_store/_config.py line 246 and 270 Severity: Medium

Description¶

When a YAML or TOML config file specifies options: with no value (producing Python None), from_dict calls dict(None) or dict(prof.get("options", {})) where the get returns None (key exists with null value). This raises an unhelpful TypeError.

Reproduction¶

from remote_store._config import RegistryConfig

config_data = {
    "backends": {
        "mybackend": {
            "type": "memory",
            "options": None,    # YAML "options:" with no value
        }
    },
    "stores": {},
}

RegistryConfig.from_dict(config_data)
# TypeError: 'NoneType' object is not iterable

Execution result¶

TypeError: 'NoneType' object is not iterable

Root cause¶

Line 246: options = dict(cfg.get("options", {})). When the key "options" exists with value None, .get("options", {}) returns None (the key is present), and dict(None) raises TypeError. The same pattern exists at line 270 for store profiles.

B-4 — RegistryConfig.from_dict silently converts null to string "None"¶

File: src/remote_store/_config.py lines 257, 268–269 Severity: Medium

Description¶

str(None) produces the string "None" in Python. When YAML/TOML config files contain null values for type, backend, or root_path, from_dict silently converts them to the literal string "None" instead of raising a validation error. This causes files to be stored under a None/ prefix or backend lookups to fail with a confusing "unknown backend type 'None'" error.

Reproduction¶

from remote_store._config import RegistryConfig
from remote_store.backends._memory import MemoryBackend
from remote_store._store import Store

config = RegistryConfig.from_dict({
    "backends": {"b": {"type": "memory"}},
    "stores": {"s": {"backend": "b", "root_path": None}},
})

print(repr(config.stores["s"].root_path))  # 'None'

# Using this profile corrupts paths:
store = Store(MemoryBackend(), root_path=config.stores["s"].root_path)
store.write("file.txt", b"data", overwrite=True)
# File stored at "None/file.txt" instead of "file.txt"

Execution result¶

root_path repr: 'None'
File at None/file.txt: True
File at file.txt:      False

Root cause¶

str() coercion at lines 257 (str(cfg["type"])), 268 (str(prof["backend"])), and 269 (str(prof.get("root_path", ""))) treats None as a valid input instead of validating that required fields are strings.

B-5 — partition_path allows `=` in key — round-trip fails¶

File: src/remote_store/ext/partition.py lines 65–76 Severity: Low

Description¶

partition_path validates that = is not in the partition value (line 73–74) but does not validate the partition key. A key containing = produces a segment like col=x=val with two = signs, which parse_partition cannot parse (it requires exactly one = per segment).

Reproduction¶

from remote_store.ext.partition import partition_path, parse_partition

path = partition_path("data.parquet", **{"col=x": "val"})
# 'col=x=val/data.parquet'

parsed = parse_partition(path)
print(parsed.partitions)   # {} — key lost
print(parsed.filename)     # 'col=x=val/data.parquet' — entire path is filename

Execution result¶

partition_path output: 'col=x=val/data.parquet'
Partitions recovered:  {}
Filename recovered:    'col=x=val/data.parquet'
Round-trip: FAILED

Root cause¶

Line 73 checks if "=" in str_value for values but there is no corresponding check for keys. _is_partition_segment at line 122–124 requires segment.count("=") == 1, so any key with = produces unparseable output.

Notes¶

Azure start_copy_from_url race condition: The non-HNS code paths in backends/_azure.py lines 661–662 (move) and 681 (copy) call start_copy_from_url() without waiting for the async server-side copy to complete before deleting the source (move) or returning (copy). This is a real data-loss risk for large blobs or cross-account copies but cannot be reproduced without an Azure environment.
ChecksumWriter / ProgressWriter partial-write semantics: Both wrappers in ext/streams.py update hash/callback based on input data length rather than actual bytes written. This is explicitly documented as a known limitation ("Assumes buffered I/O semantics"). Users wrapping RawIOBase streams will get incorrect checksums/progress. Noted here for completeness.

Audit 008 — Package Bugs (User-Facing)¶

Summary¶

B-1 — CachedStore: write doesn't invalidate parent directory metadata¶

Description¶

Reproduction¶

Execution result¶

Root cause¶

B-2 — CachedStore.child() creates isolated cache¶

Description¶

Reproduction¶

Execution result¶

Root cause¶

B-3 — RegistryConfig.from_dict crashes on YAML/TOML null options¶

Description¶

Reproduction¶

Execution result¶

Root cause¶

B-4 — RegistryConfig.from_dict silently converts null to string "None"¶

Description¶

Reproduction¶

Execution result¶

Root cause¶

B-5 — partition_path allows = in key — round-trip fails¶

Description¶

Reproduction¶

Execution result¶

Root cause¶

Notes¶

B-5 — partition_path allows `=` in key — round-trip fails¶