[Django] #36620: Automate test coverage check on pull requests

[Django]

#36620: Automate test coverage check on pull requests
-------------------------------------+-------------------------------------
Reporter: Jacob Walls | Type:
| Cleanup/optimization
Status: new | Component: Core
| (Other)
Version: dev | Severity: Normal
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
We could automate a significant part of checking test coverage on pull
requests. Instead of using a cloud service, there's an implementation
using `diff-cover` in a PR.

[https://github.com/django/django/pull/19777 PR]

[https://forum.djangoproject.com/t/rfc-prioritizing-tasks-for-automate-
processes-within-django-contribution-workflow-gsoc-2025/41960 Forum post]
--
Ticket URL: <https://code.djangoproject.com/ticket/36620>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

[Django]

#36620: Automate test coverage check on pull requests
-------------------------------------+-------------------------------------

Reporter: Jacob Walls | Owner: Saurabh
Type: | Status: assigned
Cleanup/optimization |

Component: Core (Other) | Version: dev

Severity: Normal | Resolution:

Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Jacob Walls):

* owner: (none) => Saurabh
* status: new => assigned

--
Ticket URL: <https://code.djangoproject.com/ticket/36620#comment:1>

[Django]

#36620: Automate test coverage check on pull requests
-------------------------------------+-------------------------------------
Reporter: Jacob Walls | Owner: Saurabh
Type: | Status: assigned
Cleanup/optimization |
Component: Core (Other) | Version: dev
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Simon Charette):

I think the last time this was attempted the efforts stalled due the
difficulty of combining coverage reports from different suite runs. Some
part of the code is only covered by tests run on Postgres or a particular
Python version for example so there needs to be a coordinated job that
collects all of the `.coverage` artifacts and
[https://coverage.readthedocs.io/en/7.10.7/commands/cmd_combine.html then
combine them] otherwise the resulting coverage report will be lacking or
improperly reporting that some areas are not covered (e.g. if we only use
the SQLite test run and Postgres only changes are introduced).
--
Ticket URL: <https://code.djangoproject.com/ticket/36620#comment:2>

[Django]

#36620: Automate test coverage check on pull requests
-------------------------------------+-------------------------------------
Reporter: Jacob Walls | Owner: Saurabh
Type: | Status: assigned
Cleanup/optimization |
Component: Core (Other) | Version: dev
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Jacob Walls):

(The linked implementation just treats that complexity as outside of MVP
and makes this caveat explicit in the posted comment.)
--
Ticket URL: <https://code.djangoproject.com/ticket/36620#comment:3>

[Django]

#36620: Automate test coverage check on pull requests

--------------------------------------+------------------------------------

Reporter: Jacob Walls | Owner: Saurabh

Type: Cleanup/optimization | Status: assigned

Component: Core (Other) | Version: dev
Severity: Normal | Resolution:

Keywords: | Triage Stage: Accepted

Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

--------------------------------------+------------------------------------
Changes (by Sarah Boyce):

* stage: Unreviewed => Accepted

--
Ticket URL: <https://code.djangoproject.com/ticket/36620#comment:4>

[Django]

#36620: Automate test coverage check on pull requests
--------------------------------------+------------------------------------
Reporter: Jacob Walls | Owner: Saurabh
Type: Cleanup/optimization | Status: assigned
Component: Core (Other) | Version: dev
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 1 | Needs documentation: 1
Needs tests: 0 | Patch needs improvement: 1

Easy pickings: 0 | UI/UX: 0
--------------------------------------+------------------------------------
Changes (by Sarah Boyce):

* needs_better_patch: 0 => 1
* needs_docs: 0 => 1

--
Ticket URL: <https://code.djangoproject.com/ticket/36620#comment:5>