gh-148849: Deprecate http.cookies.BaseCookie.js_output() by kishorhange111 · Pull Request #148978 · python/cpython · GitHub

gh-148849: Deprecate http.cookies.BaseCookie.js_output()

I didn’t see anyone assigned to this issue, so I tried working on it. I’m new to open source contributions, so please let me know if anything should be done differently.

This deprecates BaseCookie.js_output() as discussed in the issue. The method seems to be unused and tied to older browser behavior that isn’t really relevant anymore.

I added a deprecation decorator to the method, updated the existing tests to expect a DeprecationWarning, and updated the docs along with a NEWS entry.

I ran test_http_cookies locally — all tests pass (33 tests, 1 skipped):

Ran 33 tests in 0.122s
OK (skipped=1)

I also checked that calling js_output() raises the warning while still returning the same result.

I left Morsel.js_output() unchanged since the issue only mentions BaseCookie.js_output(), but I can update that too if needed.

Would appreciate a review whenever you get a chance. Thanks!

Fixes gh-148849

📚 Documentation preview 📚: https://cpython-previews--148978.org.readthedocs.build/

All commit authors signed the Contributor License Agreement.

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

Please, do not update your branch if there is no need to. Please read https://devguide.python.org/getting-started/pull-request-lifecycle/ before doing future contributions.

I have made the requested changes; please review again

Thanks for making the requested changes!

@picnixz: please review the changes made to this pull request.

Please let me know if there are any further suggestions or changes needed.

Co-authored-by: Stan Ulbrych <stan@python.org>

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

I have made the requested changes; please review again

Thanks for making the requested changes!

@picnixz: please review the changes made to this pull request.

Nothing to do on your side! Don't update your branch since there won't be a need to, I'll just wait a few days before alpha closes to merge this.

cc @sethmlarson @serhiy-storchaka @encukou

LGTM!

LGTM. 👍

Sorry for being late to the party, but, IMO Morsel.js_output should be deprecated as well -- it has exactly the same issues.
(and BaseCookie uses that, so the warning should only be emitted there.)

Hey, quick question — should I include this change in the current PR, or would you prefer I open a separate PR specifically for the Morsel.js_output update?

I'd prefer here since they're so related.

…tion

I have made the requested changes; please review again.

As suggested by @encukou, I’ve deprecated Morsel.js_output(). The implementation now routes through Morsel.js_output(), so the deprecation warning is emitted only once.

Note on stacklevel:
The current implementation uses warnings._deprecated(), which has a fixed stacklevel=3. As a result, when BaseCookie.js_output() calls Morsel.js_output(), the warning points to BaseCookie.js_output() rather than the user's code. This could be improved by switching to warnings.warn() with a configurable stacklevel.
I'm happy to adjust this if preferred .

Thanks for making the requested changes!

@picnixz, @StanFromIreland, @serhiy-storchaka: please review the changes made to this pull request.

Documentation build overview

📚 cpython-previews | 🛠️ Build #32507822 | 📁 Comparing a91d066 against main (db0ee44)

🔍 Preview build

40 files changed · ± 40 modified

± Modified

To avoid multiple deprecation warnings from internal use, you can add private Morsel._js_output and use it in BaseCookie.js_output and Morsel.js_output after emitting a warning.

You can use self.assertEqual(cm.filename, __file__) to assert that the warning points to the correct calling place.

@serhiy-storchaka Thank you so much for the suggestion!
I've added Morsel._js_output() as a protected method containing the actual logic, so both Morsel.js_output() and BaseCookie.js_output() can warn independently and then delegate to _js_output(). This cleanly avoids multiple warnings and also fixes the stacklevel issue. I've also added cm.filename == file assertions to verify that the warning correctly points to the user's call site.

Thank you!

pythongh-148849 : Deprecate http.cookies.BaseCookie.js_output()

f67449d

kishorhange111 requested a review from AA-Turner as a code owner April 25, 2026 07:47

bedevere-app Bot added the awaiting review label Apr 25, 2026

bedevere-app Bot mentioned this pull request Apr 25, 2026

Deprecate BaseCookie.js_output() method #148849

Closed

picnixz requested changes Apr 25, 2026

View reviewed changes

bedevere-app Bot added awaiting changes and removed awaiting review labels Apr 25, 2026

StanFromIreland reviewed Apr 25, 2026

View reviewed changes

Comment thread Doc/library/http.cookies.rst Outdated

Comment thread Misc/NEWS.d/next/Library/2026-04-25-12-04-27.gh-issue-148849.Vk6yEW.rst Outdated

Address review comments

d1e4a57

kishorhange111 force-pushed the gh-148849-deprecate-js-output branch from d9ae235 to d1e4a57 Compare April 25, 2026 08:26

Version updated to 3.19

627fa9b

bedevere-app Bot added awaiting change review and removed awaiting changes labels Apr 25, 2026

bedevere-app Bot requested a review from picnixz April 25, 2026 08:58

Fix deprecation warning implementation

60cf501

StanFromIreland reviewed Apr 25, 2026

View reviewed changes

Comment thread Doc/library/http.cookies.rst Outdated

Update Doc/library/http.cookies.rst

964c27f

Co-authored-by: Stan Ulbrych <stan@python.org>

picnixz reviewed Apr 25, 2026

View reviewed changes

Comment thread Doc/whatsnew/3.15.rst Outdated

picnixz reviewed Apr 25, 2026

View reviewed changes

Comment thread Lib/http/cookies.py Outdated

picnixz reviewed Apr 25, 2026

View reviewed changes

Comment thread Lib/test/test_http_cookies.py Outdated

kishorhange111 and others added 2 commits April 25, 2026 15:09

Update Doc/whatsnew/3.15.rst

3d31227

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

Fix deprecation warning message to match tests

b169fc8

picnixz reviewed Apr 27, 2026

View reviewed changes

Comment thread Lib/http/cookies.py

Update Lib/http/cookies.py

ed75b1e

picnixz reviewed Apr 27, 2026

View reviewed changes

Comment thread Lib/http/cookies.py Outdated

Update Lib/http/cookies.py

38f1708

picnixz approved these changes Apr 27, 2026

View reviewed changes

bedevere-app Bot added awaiting merge and removed awaiting change review labels Apr 27, 2026

sethmlarson approved these changes Apr 27, 2026

View reviewed changes

serhiy-storchaka approved these changes Apr 27, 2026

View reviewed changes

StanFromIreland approved these changes Apr 27, 2026

View reviewed changes

kishorhange111 added 2 commits May 2, 2026 07:36

pythongh-148849 : Deprecate Morsel.js_output()

948a8f8

pythongh-148849 : Fix duplicate Morsel.js_output doc entry and indenta…

c957098

…tion

bedevere-app Bot added awaiting change review and removed awaiting merge labels May 2, 2026

bedevere-app Bot requested review from StanFromIreland, picnixz and serhiy-storchaka May 2, 2026 08:01

serhiy-storchaka reviewed May 2, 2026

View reviewed changes

pythongh-148849 : Add Morsel._js_output() to avoid multiple warnings

a91d066

sethmlarson approved these changes May 3, 2026

View reviewed changes

serhiy-storchaka removed the awaiting change review label May 4, 2026

serhiy-storchaka merged commit 246fe14 into python:main May 4, 2026
52 of 53 checks passed

gh-148849: Deprecate http.cookies.BaseCookie.js_output() by kishorhange111 · Pull Request #148978 · python/cpython · GitHub

Repository navigation

gh-148849: Deprecate http.cookies.BaseCookie.js_output() - #148978

gh-148849: Deprecate http.cookies.BaseCookie.js_output()#148978serhiy-storchaka merged 14 commits intopython:mainpython/cpython:mainfrom kishorhange111:gh-148849-deprecate-js-outputkishorhange111/cpython:gh-148849-deprecate-js-outputCopy head branch name to clipboard

Conversation

kishorhange111 commented Apr 25, 2026 • edited by github-actions Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

python-cla-bot Bot commented Apr 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

bedevere-app Bot commented Apr 25, 2026

Uh oh!

picnixz commented Apr 25, 2026

Uh oh!

Uh oh!

Uh oh!

kishorhange111 commented Apr 25, 2026

Uh oh!

bedevere-app Bot commented Apr 25, 2026

Uh oh!

kishorhange111 commented Apr 25, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

kishorhange111 commented Apr 25, 2026

Uh oh!

bedevere-app Bot commented Apr 25, 2026

Uh oh!

Uh oh!

Uh oh!

picnixz commented Apr 27, 2026

Uh oh!

sethmlarson left a comment

Choose a reason for hiding this comment

Uh oh!

serhiy-storchaka left a comment

Choose a reason for hiding this comment

Uh oh!

encukou commented May 1, 2026

Uh oh!

kishorhange111 commented May 1, 2026

Uh oh!

encukou commented May 1, 2026

Uh oh!

kishorhange111 commented May 2, 2026

Uh oh!

bedevere-app Bot commented May 2, 2026

Uh oh!

read-the-docs-community Bot commented May 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Documentation build overview

Uh oh!

serhiy-storchaka left a comment

Choose a reason for hiding this comment

Uh oh!

kishorhange111 commented May 2, 2026

Uh oh!

sethmlarson left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

gh-148849: Deprecate http.cookies.BaseCookie.js_output()#148978
serhiy-storchaka merged 14 commits into
python:mainfrom
kishorhange111:gh-148849-deprecate-js-output

kishorhange111 commented Apr 25, 2026 •
edited by github-actions Bot
Loading

python-cla-bot Bot commented Apr 25, 2026 •
edited
Loading

read-the-docs-community Bot commented May 2, 2026 •
edited
Loading