You can see the evolution of your hotspots over time with code-compass' c/show-hotspot-snapshot-sync.

I showed previously that hotspots help you find part of your codebase receiving a great number of changes. These parts move from hot to cool over time. What if you want to know what parts were hot?

Apart of curiosity, it is useful to know how and where your codebase received significant amount of changes when you are looking for places to refactor.

Also say you find two hotspots in your codebase that you think requires your attention: how do you prioritize between them? If you know how fast they heated up, you can choose!

Well this one is sweet and short: just run the hotspot analysis of code-compass over the list of periods you need and compare the browser tabs!

Code-compass provides this for you:

(defun c/show-hotspot-snapshot-sync (repository)
  "Snapshot COMMAND over REPOSITORY over the last year every three months."
  (interactive
   (list
    (read-directory-name "Choose git repository directory:" (vc-root-dir))))
  (--each c/snapshot-periods (c/show-hotspots-sync repository (c/request-date it) 8888)))

You can see that it is just an iterations over the periods. You can set the periods that you need: I set as default the last year trimesters

(defcustom c/snapshot-periods
  '("1d" "3m" "6m" "9m" "12m" "15m")
  "A list of snapshots periods to show evolution of analyses over time."
  :group 'code-compass)

Note that it may be that there were no changes in those periods and you get an empty tab: this is expected and I did not put effort in fixing it yet.

Just try creating your hotspot snapshots out! It is just calling c/show-hotspot-snapshot-sync and you will have some further insight from the precious hotspot analysis!

Happy journeying & Merry Christmas!