Build the websocket reader_c extension without the reader_c.py symlink

[bdraco]

What do these changes do?

Removes the aiohttp/_websocket/reader_c.py symlink; the extension is now compiled directly from reader_py.py using cython --module-name aiohttp._websocket.reader_c. The symlink only existed so Cython would pair the source with reader_c.pxd and emit the right module name, but after #13388 the wheel build materializes it as a regular file in site-packages, which coverage then reports as a new 0% file.

Are there changes in behavior for the user?

No runtime changes; dists no longer contain a stray reader_c.py file, reader_c only exists as the compiled extension.

Is it a substantial burden for the maintainers to support this?

No, it is one less special case; the Makefile rule is the only thing that changed.

Related issue number

Follow up to #13388

Checklist

• I think the code is well written
• Unit tests for the changes exist
  • N/A, build tooling only, covered by the existing websocket test suite with extensions enabled
• Documentation reflects the changes
  • N/A
• If you provide code modification, please add yourself to CONTRIBUTORS.txt
  • N/A, already listed
• Add a new news fragment into the CHANGES/ folder
  • name it <issue_or_pr_num>.<type>.rst (e.g. 588.bugfix.rst)

Drafted with Claude Code; reviewed by bdraco.

[codspeed-hq]

Merging this PR will not alter performance

✅ 84 untouched benchmarks
⏩ 83 skipped benchmarks¹

---

_{Comparing drop-reader-c-symlink (b145e49) with master (7dc43ae)²}

Footnotes

1. 83 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on master (7394da3) during the generation of this report, so 7dc43ae was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.99%. Comparing base (7dc43ae) to head (b145e49).
⚠️ Report is 10 commits behind head on master.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #13457      +/-   ##
==========================================
+ Coverage   98.42%   98.99%   +0.57%     
==========================================
  Files         133      132       -1     
  Lines       49747    49455     -292     
  Branches     2628     2571      -57     
==========================================
- Hits        48961    48960       -1     
+ Misses        662      371     -291     
  Partials      124      124              

Flag	Coverage Δ
Autobahn	22.08% <0.00%> (+0.12%)	⬆️
CI-GHA	98.90% <0.00%> (+0.58%)	⬆️
OS-Linux	98.68% <0.00%> (+0.58%)	⬆️
OS-Windows	97.03% <0.00%> (+0.57%)	⬆️
OS-macOS	97.92% <0.00%> (+0.57%)	⬆️
Py-3.10	98.12% <0.00%> (+0.58%)	⬆️
Py-3.11	98.38% <0.00%> (+0.58%)	⬆️
Py-3.12	98.46% <0.00%> (+0.57%)	⬆️
Py-3.13	98.45% <0.00%> (+0.57%)	⬆️
Py-3.14	98.47% <0.00%> (+0.57%)	⬆️
Py-3.14t	97.56% <0.00%> (+0.57%)	⬆️
Py-pypy-3.11	97.43% <0.00%> (+0.57%)	⬆️
VM-macos	97.92% <0.00%> (+0.57%)	⬆️
VM-ubuntu	98.68% <0.00%> (+0.58%)	⬆️
VM-windows	97.03% <0.00%> (+0.57%)	⬆️
cython-coverage	82.18% <0.00%> (-0.01%)	⬇️

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[webknjaz]

pre-commit.ci run

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge, with no concrete build, runtime, packaging, security, or consumer compatibility defect established.

The explicit Cython module name preserves the compiled extension identity, pure-Python fallback remains available when the extension is absent, and the remaining source edit only removes a coverage directive.

_{Reviews (1): Last reviewed commit: "Remove stale no branch pragma from the w..." | Re-trigger Greptile}

[webknjaz]

I like this overall.

Though, is this me or does the last in-branch commit come with a bunch of sudden indirect coverage increase? https://app.codecov.io/gh/aio-libs/aiohttp/commit/b145e495a4611ffdbc2fe3318989f5f312a0d7c4/indirect-changes. Is this flaky/unrelated?

[webknjaz]

Suggested change

	Removed the ``aiohttp/_websocket/reader_c.py`` symlink from the source tree; the ``aiohttp._websocket.reader_c`` extension is now compiled directly from ``reader_py.py`` using ``cython --module-name``, so distributions no longer include a ``reader_c.py`` file that showed up as an uncovered module in coverage reports -- by :user:`bdraco`.
	Removed the :file:`aiohttp/_websocket/reader_c.py` symlink from the source tree; the ``aiohttp._websocket.reader_c`` extension is now compiled directly from :file:`reader_py.py` using :command:`cython --module-name`, so distributions no longer include a :file:`reader_c.py` file that showed up as an uncovered module in coverage reports -- by :user:`bdraco`.

[Dreamsorcerer]

Though, is this me or does the last in-branch commit come with a bunch of sudden indirect coverage increase? https://app.codecov.io/gh/aio-libs/aiohttp/commit/b145e495a4611ffdbc2fe3318989f5f312a0d7c4/indirect-changes. Is this flaky/unrelated?

Probably last commit on master failed, so has less coverage. The expected coverage is 98.99%, so it's correct.

[patchback]

Backport to 3.15: 💚 backport PR created

✅ Backport PR branch: patchback/backports/3.15/e54b79cbae69e24d5e87469613e97a3d9bec0d4b/pr-13457

Backported as #13469

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[patchback]

Backport to 3.14: 💚 backport PR created

✅ Backport PR branch: patchback/backports/3.14/e54b79cbae69e24d5e87469613e97a3d9bec0d4b/pr-13457

Backported as #13470

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.