fix(explore): retain chart ownership on query context update

[villebro]

SUMMARY

A feature was recently introduced to automatically populate query_context in the chart metadata if it was missing. This was necessary to be able to render V1 chart reports, which require the frontend-rendered query request (not possible by the backend). However, if a non-owner triggered the chart update command, the original ownership data was lost due to the update payload not containing the owners property. This was due to the self.populate_owners method setting the owners to whichever value was passed in the request, which in this case was always None.

This PR changes the chart update command to not modify the owners property when calling the chart update command with query_context_generation. In addition, an integration test is added to ensure that a non-owner can update the query context payload without changing the owners property (test fails on master).

TESTING INSTRUCTIONS

1. Start a fresh installation of Superset with a newly initiated metadata database and examples data populated
2. Login as Admin
3. Go to the Charts page and change one of the Examples chart owners from empty to "Admin"
4. Open the chart into Explore view
5. Go back to Charts page and check the chart owners - notice how the owners are empty again. Set the chart owner back to Admin.
6. Reopen the chart in Explore, go to the Charts page and notice that now Admin is still an owner.

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #16419 (affdd3a) into master (486ef6b) will decrease coverage by 0.00%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master   #16419      +/-   ##
==========================================
- Coverage   76.55%   76.55%   -0.01%     
==========================================
  Files        1000     1000              
  Lines       53487    53486       -1     
  Branches     6818     6818              
==========================================
- Hits        40948    40947       -1     
  Misses      12301    12301              
  Partials      238      238              

Flag	Coverage Δ
hive	81.26% <50.00%> (+0.03%)	⬆️
mysql	81.52% <50.00%> (-0.01%)	⬇️
postgres	81.55% <50.00%> (-0.01%)	⬇️
presto	81.33% <50.00%> (-0.01%)	⬇️
python	82.06% <50.00%> (-0.01%)	⬇️
sqlite	81.19% <50.00%> (+0.03%)	⬆️

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

Impacted Files	Coverage Δ
superset/charts/commands/update.py	88.73% <50.00%> (-0.16%)	⬇️

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[rusackas]

Fixies issues that will reappear after merging #16408

[zhaoyongjie]

LGTM, BTW, the detailed test case saves lots of review time.

[rosemarie-chiu]

🏷 2021.31