Investigate Configuring test selection of Test Jobs #1423
Description
Leading on from internal talks on how to improve sustainability, one idea raised was to configure the Github Actions workflow so that it does not execute every test job on every commit. The best configuration option found so far, would reduce the number of test jobs executed by 13%. More information on configuration options and findings can be found in this PR #1417.
Another related idea is to introduce test selection into the test jobs themselves, where if a job is run, then not every test is executed, but rather only relevant tests. For the front-end 1 option is using vitest's --changed option, which does exactly that. No analysis has been done to quantify how large the reduction would be, however I think it would conservatively be a 50% reduction in the number of tests executed (for unit test jobs).