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Jest Web Test Run Initialization is Slow O(10x) Slower than it Should Be

See original GitHub issue

Problem When running jest tests the runtime seems to be 12-14 seconds just to spin up a test and mount a component. The actual tests are fast. That implies 99% of the wall time is due to setup – possibly because we have several chained yarn calls but most likely due to source maps (usual suspect for this).

As evidence, API tests are MUCH faster.

 PASS   api  api/src/services/stages/stages.test.ts
  stages
    ✓ returns all stages (45 ms)
    ✓ returns a single stage (19 ms)
    ✓ creates a stage (16 ms)
    ✓ updates a stage (14 ms)
    ✓ deletes a stage (12 ms)

Test Suites: 1 passed, 1 total
Tests:       5 passed, 5 total
Snapshots:   0 total
Time:        1.043 s

 FAIL   web  web/src/layouts/DefaultLayout/DefaultLayout.test.tsx (13.13 s)
  DefaultLayout
    ✓ defaults to open (260 ms)
    ✓ opens on menu click (88 ms)
    ✓ closes on chevron click (58 ms)
    ✕ should navigate to '/home' (47 ms)
    ✓ renders successfully (33 ms)

Resolution We should probably add an option to ignore source maps / use an ugly version by default and then use a full fidelity one when useing a debugger launch config – something like that.

I have a PR cooking that adds the debugging config for jest in vscode. I may be able to address this as well with a bit of advice on where to stick an option – perhaps just as an ENV variable.