CounterStrike.counter_example is called at compile time, and can cause ElixirLS to crash #234
Description
Hello
I've encountered an issue that makes development with propcheck difficult for me when using ElixirLS.
As far as I can tell, the language server attempts to call Counterstrike.counter_example at compile time, but the target process cannot be found. This causes ElixirLS to crash.
Error Message
[Info - 16:17:09] Terminating Elixir.ElixirLS.LanguageServer.ExUnitTestTracer: exited in: GenServer.call(PropCheck.CounterStrike, {:counter_example, {PropCheck.TreeTest, :property_delete, []}}, 5000)
** (EXIT) no process: the process is not alive or there's no process currently associated with the given name, possibly because its application isn't started
[Error - 16:17:09] GenServer ElixirLS.LanguageServer.ExUnitTestTracer terminating
** (stop) exited in: GenServer.call(PropCheck.CounterStrike, {:counter_example, {PropCheck.TreeTest, :property_delete, []}}, 5000)
** (EXIT) no process: the process is not alive or there's no process currently associated with the given name, possibly because its application isn't started
(elixir 1.18.3) lib/gen_server.ex:1121: GenServer.call/3
(propcheck 1.5.1-dev) lib/properties.ex:171: PropCheck.Properties.tag_property/1
test/tree_test.exs:13: (module)
(elixir 1.18.3) src/elixir_compiler.erl:77: :elixir_compiler.dispatch/4
(elixir 1.18.3) src/elixir_compiler.erl:52: :elixir_compiler.compile/4
(elixir 1.18.3) src/elixir_module.erl:454: :elixir_module.eval_form/7
(elixir 1.18.3) src/elixir_module.erl:156: :elixir_module.compile/7
(elixir 1.18.3) src/elixir_compiler.erl:38: :elixir_compiler.maybe_fast_compile/2
(elixir 1.18.3) src/elixir_lexical.erl:13: :elixir_lexical.run/3
(elixir 1.18.3) src/elixir_compiler.erl:17: :elixir_compiler.quoted/3
(elixir 1.18.3) lib/module/parallel_checker.ex:120: Module.ParallelChecker.verify/1
(language_server 0.27.2) lib/language_server/ex_unit_test_tracer.ex:84: anonymous fn/1 in ElixirLS.LanguageServer.ExUnitTestTracer.handle_call/3
(kernel 10.2.7) global.erl:699: :global.trans/4
(language_server 0.27.2) lib/language_server/ex_unit_test_tracer.ex:77: ElixirLS.LanguageServer.ExUnitTestTracer.handle_call/3
(stdlib 6.2.2) gen_server.erl:2381: :gen_server.try_handle_call/4
(stdlib 6.2.2) gen_server.erl:2410: :gen_server.handle_msg/6
To Reproduce
Tools
- elixir: 1.18.3 (installed via asdf)
- erlang: 27.3.4 (installed via asdf)
- VSCode: 1.100.0
- ElixirLS VSCode extension: 0.27.2
Steps
- Open propcheck repository in VSCode (I'd expect the same issue is present in other editors when using the same language server)
- Navigate to
test/tree_test.exs - Make some edits inside of a
forallblock (I've found that just deleting aTree.memberfunction call and then adding it back is sufficient.) - ElixirLS should crash, with an error like above
Note that I first encounted this issue in a repo that was using propcheck as a dependency, so it is not exclusive to the propcheck repository. It's just convenient that it can be reproduced in the propcheck repo itself.
My Investigation
I think that the root cause is from CounterStrike.counter_example being called in Properties.tag_property. From my understanding, the tags are computed at compile time and so CounterStrike.counter_example must be called at compile time.
If I replace:
def tag_property({m, f, a}) do
mfa = {m, String.to_atom("property_#{f}"), a}
case CounterStrike.counter_example(mfa) do
{:ok, _} ->
# Logger.debug "Found failing property #{inspect mfa}"
true
_ ->
false
end
endwith:
def tag_property({m, f, a}) do
false
endthen the issue stops, and I can edit propcheck tests without errors. (Although this is of course not a proper fix, as it breaks the counter example tagging functionality.)
I'm fairly new to Elixir and I don't have a lot of experience with macros/metaprogramming, so it's possible I've misunderstood something here.
Related Issues
Somebody reported what seems like the same issue on the ElixirLS repo.