Fix #104 dataframe histogram memoization

[blrnw3]

Memo was being set up on every call rather than once per instance, causing some UI features to be slow
e.g. https://app.zenhub.com/workspaces/single-cell-5e2a191dad828d52cc78b028/issues/chanzuckerberg/single-cell-explorer/104.

These were the only instances of memo not working correctly that I could find. Also, this issue does not affect cellxgene desktop as the bug was introduced during the TS migration.

Perf screenshots when clicking a CatVar drop down (following the steps to reproduce above).
Before

After

Reviewers

Functional:
Bruce
Readability:
Seve

Changes

• Fix memoization for dataframe's histogram functions

[bkmartinjr]

Nice fix, which looks good. And embarrassing given this was my bug!

It is very likely the cellxgene repo has the same issue. Can you apply the fix to both?

[codecov]

Codecov Report

Merging #116 (1de5663) into main (d41d92b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #116   +/-   ##
=======================================
  Coverage   71.83%   71.83%           
=======================================
  Files         126      126           
  Lines       10106    10106           
=======================================
  Hits         7260     7260           
  Misses       2846     2846           

Flag	Coverage Δ
frontend	71.83% <ø> (ø)
javascript	71.83% <ø> (ø)
unitTest	71.83% <ø> (ø)

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[blrnw3]

It is very likely the cellxgene repo has the same issue. Can you apply the fix to both?

@bkmartinjr It looks like cellxgene is not affected because the bug was introduced during the TS migration, which seems to have only been done on the hosted code. Is there a plan to convert cellxgene to TS?

[bkmartinjr]

Is there a plan to convert cellxgene to TS?

No, there is not. Thanks for checking!