AVA hangs after all tests pass

[rrthomas]

I have a small project with a simple test suite, with no async code (that I'm aware of, at least!): https://github.com/ursalang/ark

When I run the tests, they all pass, but AVA hangs and runs indefinitely at 100% CPU.

The output looks like this:

  ✔ basics › Concrete values
  ✔ basics › Intrinsics
  ✔ basics › Sequences
  ✔ basics › Conditionals
  ✔ basics › Bare break
  ✔ basics › loop and break
  ✔ basics › let
  ✔ basics › Objects
  ✔ basics › Lists
  ✔ basics › Maps
  ✔ examples › Increment a variable in a loop
  ✔ examples › Sum ints from 1 to 10
  ✔ examples › Call first-class function
  ✔ examples › Factorial (recurse with symbol reference)
  ✔ examples › Factorial (recurse with function argument)
  ✔ examples › Sum list (break result)
  ✔ examples › Sum list (return result)
  ✔ examples › Double list
  ✔ examples › Assign to table
  ✔ examples › Repeated closure
  
  ✘ Timed out while running tests

At the end, AVA is still running.

AVA configuration (from package.json):

"ava": {
    "typescript": {
      "rewritePaths": {
        "src/": "lib/"
      },
      "compile": "tsc"
    }
  },

AVA invocation: npx ava.
AVA version: 5.3.1

Apologies for not providing a minimal example yet; I will endeavour to whittle it down. I note already that even running one of the tests using e.g.

npx ava --match "Lists" src/basics.test.ts

will cause the hang sometimes. The more tests I run, the more often it hangs, it seems. Running one of the two test files:

npx ava src/basics.test.ts

will often but not always hang.

The code being run is entirely deterministic and non-async, so I can't see any reason why I should get different results on different runs.

I tried running the test suite on two different machines "just in case" and got the same symptoms.

Thanks for AVA!

[sindresorhus]

The problem seems to be with worker threads. Works fine if you use the --no-worker-threads flag.

[rrthomas]

Thanks ever so much for the quick response and workaround. Is there anything else you need me to do here? It sounds as though you're saying it looks like a problem with AVA?