gleam test fails with vim swap files in test directory

[glennj]

This has been bedeviling me for a while.

$ gleam test
   Compiled in 0.02s
    Running largest_series_product_test.main
exception error: #{function => <<"read_module">>,line => 74,
                   message => <<"Assertion pattern match failed">>,
                   module => <<"exercism/test_runner">>,
                   value => {error,not_utf8},
                   gleam_error => let_assert}
  in function  exercism@test_runner:read_module/1 (/Users/glennj/src/exercism/exercism.io/gleam/largest-series-product/build/dev/erlang/exercism_test_runner/_gleam_artefacts/exercism@test_runner.erl, line 96)
  in call from gleam@list:do_map/3 (/Users/glennj/src/exercism/exercism.io/gleam/largest-series-product/build/dev/erlang/gleam_stdlib/_gleam_artefacts/[email protected], line 119)
  in call from exercism@test_runner:main/0 (/Users/glennj/src/exercism/exercism.io/gleam/largest-series-product/build/dev/erlang/exercism_test_runner/_gleam_artefacts/exercism@test_runner.erl, line 134)

I finally figured out it that it occurred while I was editing the test suite (in vim). The vim swap file is not an ASCII file, and it cannot be read as a module:

$ find src/ test/ -type f -exec file '{}' +
src//largest_series_product.gleam:            ASCII text
test//.largest_series_product_test.gleam.swp: Vim swap file, version 9.1, pid 1428, user glennj, host exercism-playground, file ~glennj/src/exercism/exercism.io/gleam/largest-series-product/test/largest_series_product_test.gleam
test//largest_series_product_test.gleam:      c program text, ASCII text

In exercism/test_runner.gleam, can we filter out hidden files?

Something like this naive filtering

pub fn main() {
  let assert Ok(files) = read_directory("test")
  let files = list.filter(files, fn(file) {
      case charlist.to_string(file) {
        "." <> _ -> False
        _ -> True
      }
    })

[glennj]

The quick solution (for me) is to get vim to put my swap files elsewhere. But vim is not the only source of offending files.

[lpil]

How annoying! It would be good to have this fixed