feat: mask_url/mask_proxy display maskers; fix: deep_set now indexes into lists on numeric segments (commons-2)

mask_url/mask_proxy redact credentials from connection strings for logging
(display only, not a security control). deep_set previously destroyed a list
when a numeric path segment landed on it (isinstance(nxt, dict) check
replaced the list wholesale); it now mirrors deep_get's list indexing so a
get/set round-trip on the same dotted path never corrupts data, raising
IndexError on an out-of-range segment instead of silently mis-storing.

Signed-off-by: disqualifier <dev@disqualifier.me>

README.md

@@ -12,15 +12,15 @@ Small sync helpers shared across projects. Base is stdlib only — **no dependen
 ## Install
 
 ```
-commons @ git+ssh://git@git.rethinkstudios.io/rethink-public/commons.git@v0.2.3
+commons @ git+ssh://git@git.rethinkstudios.io/rethink-public/commons.git@v0.3.1
 # async address/geo lookups (fetch_ip / ip_location / fetch_location) need the extra:
-commons[addr] @ git+ssh://git@git.rethinkstudios.io/rethink-public/commons.git@v0.2.3
+commons[addr] @ git+ssh://git@git.rethinkstudios.io/rethink-public/commons.git@v0.3.1
 ```
 
 The base install pulls **nothing** (stdlib). Only `commons[addr]` adds `aiohttp`, and
 only for the geo lookups — the pure `commons.addr.ip` utilities ship in base.
 
-Drop the `@v0.2.3` suffix from the line above to install the latest unpinned.
+Drop the `@v0.3.1` suffix from the line above to install the latest unpinned.
 
 ## timing
 
@@ -99,22 +99,43 @@ deep_get(data, "items.1.id")             # "b"  (numeric segment indexes a list)
 deep_get(data, "in.nope.here", "DEF")    # "DEF" (missing -> default, no raise)
 
 deep_set({}, "a.b.c", 9)                 # {"a": {"b": {"c": 9}}}
+deep_set(data, "items.1.id", "B")        # updates the list element in place
+deep_get(data, "items.1.id")             # "B"  (get/set share the same grammar)
+deep_set(data, "items.9.id", "X")        # raises IndexError (out of range, no
+                                          # silent mis-store)
 ```
 
+`deep_set` mirrors `deep_get`'s list indexing: a numeric segment over an existing
+list/tuple updates that element in place rather than replacing the list with a dict.
+An out-of-range numeric segment raises `IndexError` instead of silently corrupting
+the structure.
+
 ## masking
 
 Display helpers only — they format a value for showing; they are **not a security
 control** (the underlying value is unchanged and still needs proper handling).
 
 ```python
-from commons import credit, cvv, phantom, provider
+from commons import credit, cvv, phantom, provider, mask_url, mask_proxy
 
 credit("4111 1111 1111 1234")   # "•••• •••• •••• 1234"
 cvv("123")                       # "•••"
 phantom("abcdef1234567890")      # "abcdef...7890"
 provider("4111111111111111")     # "VISA"  (VISA/MC/AMEX/UPAY/DISC/JCB/DNRS/UNKW)
+
+# redact credentials in a connection string before logging it
+mask_url("https://u:pw@api.x/v2?apiKey=SECRET&ip=8.8.8.8")
+#   -> "https://api.x/v2?apiKey=***&ip=8.8.8.8"   (userinfo dropped, secret query masked)
+mask_url("redis://:pw@127.0.0.1:6379/0")     # -> "redis://127.0.0.1:6379/0"
+mask_proxy("1.2.3.4:8080:user:supersecret")  # -> "1.2.3.4:8080:user:****"
+mask_proxy("1.2.3.4:8080")                    # -> "1.2.3.4:8080"  (no auth, untouched)
 ```
 
+`mask_url` strips `user:pass@` userinfo and replaces the values of sensitive query
+params (`apiKey`, `token`, `password`, `secret`, …; override via `keys=`) with `***`.
+`mask_proxy` bullets the password of a `host:port:user:password` spec. Non-URL /
+non-conforming input is returned unchanged.
+
 ## retry
 
 Exponential-backoff retry, sync (`retry`) and async (`aretry`). Each works as a **call

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "commons"
-version = "0.2.3"
+version = "0.3.1"
 description = "small stdlib-based sync helpers: time/timezone deltas, dotted-path dict access, display masking, ip/address tooling, and retry/backoff"
 requires-python = ">=3.10"
 dependencies = []

src/commons/__init__.py

@@ -2,8 +2,11 @@
 
 timing:  unix-timestamp deltas + timezone-aware datetime conversions, bare
          functions and a configurable Clock.
-paths:   nested dict/list access by dotted path (deep_get / deep_set).
-masking: display masking for cards / cvv / tokens (cosmetic, not a security control).
+paths:   nested dict/list access by dotted path (deep_get / deep_set); deep_set
+         mirrors deep_get's list indexing, so a get/set round-trip on the same
+         path never destroys a list.
+masking: display masking for cards / cvv / tokens, plus url/proxy credential
+         redaction for logging (cosmetic, not a security control).
 addr:    ip/address tooling — pure stdlib ip utils (`commons.addr.ip`) in base,
          async geo lookups (`commons.addr.geo`) behind the `commons[addr]` extra.
 retry:   exponential-backoff retry, sync (`retry`) and async (`aretry`), call or
@@ -16,7 +19,7 @@ for instance-scoped control. addr is exposed as a submodule (`from commons impor
 addr`); its ip helpers live under `commons.addr.ip` to keep top-level uncluttered.
 """
 from . import addr, masking, paths, timing
-from .masking import credit, cvv, phantom, provider
+from .masking import credit, cvv, mask_proxy, mask_url, phantom, provider
 from .paths import deep_get, deep_set
 from .retry import aretry, retry
 from .timing import (
@@ -59,8 +62,10 @@ __all__ = [
     "cvv",
     "phantom",
     "provider",
+    "mask_url",
+    "mask_proxy",
     "retry",
     "aretry",
 ]
 
-__version__ = "0.2.3"
+__version__ = "0.3.1"

src/commons/masking.py

@@ -3,7 +3,17 @@
 these are DISPLAY helpers only — they format a value for showing in a UI or log
 (e.g. "•••• •••• •••• 1234"). they are not a security control: the underlying
 value is unchanged and still needs proper handling (encryption at rest, etc.).
+
+card helpers: `credit`, `cvv`, `provider`. token: `phantom`. url/proxy redaction
+for logging connection strings: `mask_url`, `mask_proxy`.
 """
+from urllib.parse import parse_qsl, urlencode, urlsplit, urlunsplit
+
+SENSITIVE_QUERY_KEYS = frozenset(
+    {"apikey", "api_key", "key", "token", "access_token", "refresh_token",
+     "auth", "password", "passwd", "pwd", "pass", "secret", "client_secret",
+     "sig", "signature", "session"}
+)
 
 
 def _digits(value: str) -> str:
@@ -51,3 +61,48 @@ def provider(card_number: str) -> str:
     if n.startswith(("30", "36", "38", "39")):
         return "DNRS"
     return "UNKW"
+
+
+def mask_url(url: str, *, keys: "frozenset[str] | None" = None) -> str:
+    """redact credentials in a url for logging
+
+    strips userinfo (``user:pass@host`` -> ``host``) and replaces the values of
+    sensitive query parameters (apiKey, token, password, secret, ...) with
+    ``***``, keeping the parameter name so the shape stays readable. matching is
+    case-insensitive on the parameter name; pass ``keys`` to override the default
+    sensitive-name set. non-url or unparseable input is returned unchanged.
+    """
+    sensitive = SENSITIVE_QUERY_KEYS if keys is None else frozenset(k.lower() for k in keys)
+    try:
+        parts = urlsplit(url)
+    except ValueError:
+        return url
+    if not parts.scheme and not parts.netloc:
+        return url
+    netloc = parts.netloc
+    if "@" in netloc:
+        netloc = netloc.rsplit("@", 1)[1]
+    query = parts.query
+    if query:
+        pairs = parse_qsl(query, keep_blank_values=True)
+        query = urlencode(
+            [(k, "***" if k.lower() in sensitive else v) for k, v in pairs],
+            quote_via=lambda s, *_: s,
+        )
+    return urlunsplit((parts.scheme, netloc, parts.path, query, parts.fragment))
+
+
+def mask_proxy(spec: str) -> str:
+    """redact the password of a ``host:port:user:password`` proxy string
+
+    renders ``host:port`` when there is no auth, or ``host:port:user:****`` when
+    a user/password is present — never the password itself. leaves a plain
+    ``host:port`` untouched and returns non-conforming input unchanged.
+    """
+    parts = spec.split(":")
+    if len(parts) == 2:
+        return spec
+    if len(parts) == 4:
+        host, port, user, _ = parts
+        return f"{host}:{port}:{user}:****"
+    return spec

src/commons/paths.py

@@ -2,7 +2,10 @@
 
 `deep_get(data, "in.this.old.notation")` walks dicts (and lists, when a segment is
 a number) and returns a default instead of raising on a missing/!wrong path.
-`deep_set` writes a nested value, creating intermediate dicts.
+`deep_set` writes a nested value, creating intermediate dicts and indexing into
+existing lists on numeric segments (mirroring deep_get), so a get/set round-trip
+on the same path never corrupts a list. an out-of-range numeric segment raises
+IndexError rather than silently mis-storing.
 """
 from typing import Any
 
@@ -35,16 +38,38 @@ def deep_get(data: Any, path: str, default: Any = None, *, sep: str = ".") -> An
 def deep_set(data: dict, path: str, value: Any, *, sep: str = ".") -> dict:
     """set a nested value by dotted path, creating intermediate dicts
 
-    returns the same top-level dict for chaining. overwrites any non-dict value
-    sitting where an intermediate dict is needed.
+    returns the same top-level dict for chaining. mirrors deep_get: a numeric segment
+    indexes into an existing list/tuple instead of being treated as a dict key, so a
+    read-modify-write round-trip using the same path never corrupts a list. overwrites
+    any non-dict/non-list value sitting where an intermediate container is needed. an
+    out-of-range list index raises IndexError rather than silently mis-storing (deep_get
+    returns default on out-of-range; deep_set has no safe default to fall back to, so it
+    fails loud instead).
     """
     segments = path.split(sep)
     cur = data
     for seg in segments[:-1]:
-        nxt = cur.get(seg)
-        if not isinstance(nxt, dict):
-            nxt = {}
-            cur[seg] = nxt
-        cur = nxt
-    cur[segments[-1]] = value
+        if isinstance(cur, list):
+            idx = int(seg)
+            if not -len(cur) <= idx < len(cur):
+                raise IndexError(f"deep_set: index {seg!r} out of range for list of length {len(cur)}")
+            nxt = cur[idx]
+            if not isinstance(nxt, (dict, list)):
+                nxt = {}
+                cur[idx] = nxt
+            cur = nxt
+        else:
+            nxt = cur.get(seg)
+            if not isinstance(nxt, (dict, list)):
+                nxt = {}
+                cur[seg] = nxt
+            cur = nxt
+    last = segments[-1]
+    if isinstance(cur, list):
+        idx = int(last)
+        if not -len(cur) <= idx < len(cur):
+            raise IndexError(f"deep_set: index {last!r} out of range for list of length {len(cur)}")
+        cur[idx] = value
+    else:
+        cur[last] = value
     return data