fix: handle manufacturer ID 0 in newest_manufacturer_data

[bluetoothbot]

What

Fix newest_manufacturer_data silently returning None when the most recently inserted manufacturer ID is 0.

Why

Manufacturer ID 0 is assigned by the Bluetooth SIG to Ericsson Technology Licensing — a valid identifier that real devices may emit. The previous implementation used if manufacturer_data and (last_id := list(manufacturer_data)[-1]), which treats the key itself as a truthiness check. With last_id == 0, the walrus condition is falsy and the function returns None, dropping otherwise-valid advertisement data.

How

• Replace the walrus check with an explicit emptiness check on the dict.
• Use next(reversed(manufacturer_data)) instead of list(...)[-1] — same insertion-order semantics, no list allocation.

Testing

• Added test_newest_manufacturer_data_id_zero covering the single-entry and multi-entry cases. Test commit (909e934) precedes the fix commit (3991f6e) so reviewers can verify the failing-then-passing transition.
• Full suite: 64 passed.

🤖 Generated with Claude Code

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Quality Report

Changes: 2 files changed, 10 insertions(+), 3 deletions(-)

Code scan: clean

Tests: failed ([Errno 13] Permission denied: 'pytest')

Branch hygiene: clean

Generated by Kōan post-mission quality pipeline

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (c8bb40b) to head (3991f6e).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #219   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files            6         6           
  Lines          248       248           
  Branches        37        37           
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  Hits           248       248           

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[codspeed-hq]

Merging this PR will not alter performance

✅ 9 untouched benchmarks

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_{Comparing koan/fix-newest-manufacturer-data-id-zero (3991f6e) with main (c8bb40b)¹}

Footnotes

1. No successful run was found on main (493115d) during the generation of this report, so c8bb40b was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Copilot]

Pull request overview

Fixes newest_manufacturer_data incorrectly returning None when the newest (most recently inserted) manufacturer ID is 0 by removing a falsy-key check and selecting the newest key via reverse-iteration.

Changes:

• Replace the truthiness-based walrus condition with an explicit empty-dict guard.
• Use next(reversed(manufacturer_data)) to select the newest inserted manufacturer ID without allocating a list.
• Add a regression test covering manufacturer ID 0 for single- and multi-entry dicts.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/bluetooth_data_tools/utils.py	Fixes newest-key selection logic so manufacturer ID 0 is handled correctly and efficiently.
tests/test_utils.py	Adds regression coverage ensuring manufacturer ID 0 is not dropped.

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