fix: fetch accurate branch head

[joseph-sentry]

Purpose/Motivation

This commit is a fix for the recent issue where
branch heads were all set to the same value each
time they were updated due to a bug in the Branch
django model.

This fix creates a helper function that checks for the 2 remaining innacurate commit shas that a large number of branches were set to. If the current branch head is set to one of those shas, we update the branch head by fetching the latest commit on that branch from the db.

Note that we must use a raw sql query here to update the branch object because using the django ORM to update it would lead to the same issue we are trying to fix.

Incident to link to

https://status.codecov.com/incidents/z10fykg3c9w4

What does this PR do?

• create get_or_update_branch_head
• use get_or_update_branch_head function in many endpoints most notably: graphs (badges) and the graphql branch endpoint

[thomasrockhu-codecov]

Suggested change

	_ = get_or_update_branch_head(Commit.objects, branch, branch.repository_id)
	get_or_update_branch_head(Commit.objects, branch, branch.repository_id)

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (0cd1f15) 95.71% compared to head (0f1426f) 95.71%.

Changes have been made to critical files, which contain lines commonly executed in production. Learn more

Files	Patch %	Lines
utils/temp_branch_fix.py	90.90%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main    #352   +/-   ##
=====================================
  Coverage   95.71   95.71           
=====================================
  Files        740     741    +1     
  Lines      16720   16746   +26     
=====================================
+ Hits       16002   16027   +25     
- Misses       718     719    +1     

Flag	Coverage Δ
unit	96.03% <96.87%> (-0.02%)	⬇️
unit-latest-uploader	96.03% <96.87%> (-0.02%)	⬇️

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[codecov-staging]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Files	Patch %	Lines
utils/temp_branch_fix.py	90.90%	1 Missing ⚠️

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[codecov-qa]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (0cd1f15) 96.05% compared to head (0f1426f) 96.03%.

Files	Patch %	Lines
utils/temp_branch_fix.py	90.90%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #352      +/-   ##
==========================================
- Coverage   96.05%   96.03%   -0.02%     
==========================================
  Files         625      626       +1     
  Lines       16204    16230      +26     
==========================================
+ Hits        15565    15587      +22     
- Misses        639      643       +4     

Flag	Coverage Δ
unit	96.03% <96.87%> (-0.02%)	⬇️
unit-latest-uploader	96.03% <96.87%> (-0.02%)	⬇️

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

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

[codecov-public-qa]

Codecov Report

Merging #352 (0f1426f) into main (0cd1f15) will decrease coverage by 0.02%.
The diff coverage is 96.87%.

@@            Coverage Diff             @@
##             main     #352      +/-   ##
==========================================
- Coverage   96.05%   96.03%   -0.02%     
==========================================
  Files         625      626       +1     
  Lines       16204    16230      +26     
==========================================
+ Hits        15565    15587      +22     
- Misses        639      643       +4     

Flag	Coverage Δ
unit	96.03% <96.87%> (-0.02%)	⬇️
unit-latest-uploader	96.03% <96.87%> (-0.02%)	⬇️

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

Files	Coverage Δ
api/internal/coverage/views.py	100.00% <100.00%> (ø)
api/public/v2/branch/serializers.py	100.00% <100.00%> (ø)
api/shared/mixins.py	98.55% <100.00%> (+0.04%)	⬆️
graphql_api/types/branch/branch.py	100.00% <100.00%> (ø)
graphs/views.py	93.10% <100.00%> (-1.87%)	⬇️
utils/temp_branch_fix.py	90.90% <90.90%> (ø)

[giovanni-guidini]

please create an issue to revisit this implementation and remove if we don't need it anymore so we don't forget about this.

[thomasrockhu-codecov]

@joseph-sentry could you add a link to the incident perhaps in the code change? that would make future finding a little easier

[joseph-sentry]

please create an issue to revisit this implementation and remove if we don't need it anymore so we don't forget about this.

codecov/engineering-team#1083