Main.js/LocationTracking.js process teardown/leak warning

[tstirrat]

Narrowed down to LocationTracking.spec.js

PASS  app/views/__tests__/LocationTracking.spec.js
  ✓ renders correctly (67ms)

  console.log app/views/LocationTracking.js:133
    Can't find crossed paths

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   1 passed, 1 total
Time:        2.755s, estimated 4s
Ran all test suites matching /locationtracking/i.

Watch Usage: Press w to show more.A worker process has failed to exit gracefully and has been force exited. This is likely caused by tests leaking due to improper teardown. Try running with --runInBand --detectOpenHandles to find leaks.

Something is not doing async or teardown correctly.

[kenpugsley]

Not necessarily easy, but a good issue for someone new wanting to join the dev team.

[lewisPrescott707]

I can take a look at this one? I am a QA by trade, so would be interested in looking at this one

[summetj]

@lewisPrescott707 - All yours. Note that a lot has happened to the codebase in the last month, so verify the issue still exists.

[lewisPrescott707]

Been looking at this for a little while now and can't find the issue. Running --detectOpenHandles doesn't return anything.

Found this Jest Issue, could we add --forceExit like suggested?

@summetj @kenpugsley @tstirrat

[tstirrat]

I'd prefer not to add a "hammer" solution.. vs trying to identify/mock each dependency and use jest.useFakeTimers() etc.

Note that since #749 we care more about tests working in Main.js and the sub components in main/*, as LocationTracking.js will be removed soon enough.

[tstirrat]

@lewisPrescott707 could you add some tests around the components in main/* and see if this issue still shows?

the recent component separation may help us isolate the problem to a specific view and dependency.

[tstirrat]

If the warning doesn't show anymore, we can commit those tests and close this

[lewisPrescott707]

Found the specific dependency causing the leak, by adding tests for main/, they helped me isolate it!! Thanks @tstirrat

[summetj]

Found the specific dependency causing the leak, by adding tests for main/, they helped me isolate it!! Thanks @tstirrat

Great work, thanks!