Personally, given the gotchas you mentioned, I feel like it's easy enough to do this manually in a setup block that it doesn't warrant more stuff added to stdlib.
Andrea On Sat, 27 Jun 2020 at 13:19, Wojtek Mach <woj...@wojtekmach.pl> wrote: > It’s common to create temporary directories for tests, ideally a unique > directory per test to run them concurrently. > > I’d like to propose adding `ExUnit.Callbacks.tmp_dir!/0` and this is how > we could use it: > > defmodule MyTest do > use ExUnit.Case, async: true > > test "my test" do > assert tmp_dir!() =~ "my test" > assert File.dir?(tmp_dir!()) > end > end > > The directory is lazily created on the first call, the second call to that > function within the same test simply returns the same path. > > While the path must be unique per test, I believe it should also be > predictable to ease debugging, I picked: tmp/<module>/<test>. > > To extract the module & test name, we have two options: > > 1. Define tmp_dir!/0 as a regular function and use stack trace > 2. Define tmp_dir!/0 as a macro > > Here’s a proof of concept for option 1: > > - the code: > https://github.com/wojtekmach/elixir/commit/4c399540802a3cae583c086d865dc90d865df6c8 > - example of usage in Elixir test suite: > https://github.com/wojtekmach/elixir/commit/01df2551582dd9acdaa2f6ff982d6767763070f1 > > The downside of using stack trace is it can easily get mangled, people > shouldn’t do this: > > test "my test" do > tmp_dir!() > > Task.async(fn -> > tmp_dir!() > end) > |> Task.await() > end > > And instead do that: > > test "my test" do > tmp_dir = tmp_dir!() > > Task.async(fn -> > tmp_dir > end) > |> Task.await() > end > > I believe documenting this might be enough. > > This proposal is inspired by https://github.com/golang/go/issues/35998. > > Any feedback appreciated! > > -- > 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/066A99E3-B470-44C3-9632-F52E97AB8791%40wojtekmach.pl > . > -- 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/CAM9Rf%2BKYBZ8SFAGONa6BxrrcnRbZdxUyVHjNaFrLoL4Y6FewWA%40mail.gmail.com.
