Accept array-style keys in from_query_string

[gaoflow]

Problem

from_query_string rejects valid query strings that use array-style keys, which urllib.parse.parse_qs parses without complaint:

from benedict import benedict
benedict.from_query_string("a[]=1&a[]=2")        # ValueError: Invalid query string
benedict.from_query_string("user[name]=joe")     # ValueError: Invalid query string
benedict.from_query_string("items[0]=x&items[1]=y")  # ValueError: Invalid query string

The decode gate in QueryStringSerializer used a hardcoded character whitelist ([\w\-\%\+\.\|]) for keys and values, which omits [ and ] (and other valid characters), so any bracketed/array key fails the gate before parse_qs is ever called. Array-style keys are common (PHP and HTML-form syntax).

Fix

Replace the opaque whitelist with a structural check: split on & and require every segment to be key=value where the key is non-empty and neither side contains raw whitespace, = (key) or &. This accepts bracketed/array keys while still rejecting the other formats benedict's autodetect must distinguish (verified against the repo's own fixtures: TOML, YAML, JSON, XML, plain text and URLs are still rejected).

Tests

Added cases for array-style (a[]=1&a[]=2) and bracketed (user[name]=joe&user[age]=42) keys via both IODict.from_query_string and IODict(s, format="query_string"). Without the fix they raise ValueError; with it the query-string tests pass and the broader IO/serializer suite is green (279 passed locally). ruff check/format clean.

Disclosure: I used AI assistance (Claude) to help locate and draft this fix, under my direction and review.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.32%. Comparing base (068813d) to head (6efee94).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #577   +/-   ##
=======================================
  Coverage   98.32%   98.32%           
=======================================
  Files          64       64           
  Lines        2392     2392           
=======================================
  Hits         2352     2352           
  Misses         40       40           

Flag	Coverage Δ
unittests	98.32% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Copilot]

Pull request overview

This pull request updates the query-string deserialization logic to accept common “array-style” / bracketed keys (e.g., a[], user[name]) that are valid in real-world query strings but were previously rejected by an overly restrictive key/value character whitelist.

Changes:

• Replaces the QueryStringSerializer.decode whitelist regex gate with a structural key=value-pair validation that allows bracketed keys.
• Adds test coverage for array-style (a[]=1&a[]=2) and bracketed (user[name]=...) keys in IODict.from_query_string.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
tests/dicts/io/test_io_dict_query_string.py	Adds new query-string parsing tests for array-style and bracketed keys.
benedict/serializers/query_string.py	Updates query-string decoding validation to allow bracketed/array-style keys before calling parse_qs.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.