Yes, it is desirable and it has come up in the past: https://github.com/elixir-lang/elixir/pull/11949#issuecomment-1177262901
Although I think async: :per_module is what most people want, since the tests in the same module tend to access the same resource, opting-in for it to be per test will be welcome tho. On Thu, Aug 31, 2023 at 4:57 PM Yiming Chen <dsdsh...@gmail.com> wrote: > Currently, ExUnit's `async: true` option would run test cases in this > module synchronously, > but only run this module asynchronously along with other `async: true` > modules. > > This is to propose we add an option for ExUnit to run asynchronously by > test cases. > > # Background > 1. Async by module was a surprise > > My initial understanding of `async: true` is async by cases, instead of > modules. It's a bit surprising the behavior is later. > > 2. Async by module would behave more like synchronous tests as a module > gets more test cases > > As we grow our libraries/apps, a test module will have more and more test > cases. > It's tedious to break them into separate modules to speed up the test > suite run. > And breaking them into modules has the cost of making related tests > further from each other. > > # Benefits > 1. speed up test suite runs for libraries, apps almost effortlessly > 2. more accurate `async: xxx seconds, sync: yyy seconds` metrics > > # Caveats > > 1. Async by test cases may not run faster than async by modules: > - managing these test cases has a cost on its own > - communicating these test cases between ExUnit Server and Runner has > costs as well > 2. backward compatibility with current `async: true` behavior > > some libs or apps may rely on the async by module behavior. > we should still allow user to use `async: ture` by default, > and make async by test cases an easily opt-in feature. > > 3. Async by test cases may complex the ExUnit implementation even further > > # Potential solution > > I looked into current ExUnit implementation a little bit > I think `async by test cases` is doable, but I don't have a concrete > solution yet > > A initial idea is to: > 1. instead of saving modules in ExUnit Server, we save test cases (mfa) in > ExUnit Server > 2. when Runner asks for more async tests, ExUnit Server returns test cases > (and also modules) for Runner > > This seems to be a huge change, > so I'd like to know if this feature is desirable/feasible from the core > team's PoV before I dig more into it. > > Best, > Yiming > > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elixir-lang-core+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/51ad9575-71b9-4afe-8996-1dd9e2aea7b8n%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/51ad9575-71b9-4afe-8996-1dd9e2aea7b8n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to elixir-lang-core+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4Kh4Wwr5CQRGKkbHmsLxxtyXkL6q4Y8g7rknBaHtsE_8g%40mail.gmail.com.
