Hello!
My team has recently switched to Elixir 1.15, but we are facing issues with hiding logs in tests.
Previously, we used to pass the capture_log: true
option to ExUnit.start
in the test_helper.exs
:
ExUnit.start(capture_log: true)
That way we avoid having the console flooded with logs when running our test suite (which contains hundreds of tests), but they are still displayed when a test fails. Since Elixir 1.15 though, we started having some logs leaking despite that option. We noticed that they came from the on_exit
handlers, that run in a different process than the main test process.
Following a suggestion from José Valim, I am trying to disable logging for the console instead:
# Configure the general log level. This way logs are produced, captured,
# and displayed whenever a test fails
Logger.configure(level: :debug)
# Configure the console log level to none, so that logs are not displayed while
# running tests
Logger.configure_backend(:console, level: :none)
That works fine, but according to the doc of configure_backend/2: This function is deprecated. Use LoggerBackends.configure/2 from :logger_backends dependency.
But I am struggling to use this new dependency. I could find very little information about it and no example of repository that uses it. I tried to follow what I could understand from the documentation. I tried calling LoggerBackends.configure(LoggerBackends.Console, level: :none)
but I get:
** (exit) exited in: :gen_event.call(LoggerBackends, LoggerBackends.Console, {:configure, [level: :none]})
** (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
(stdlib 5.1) gen_event.erl:469: :gen_event.call1/3
test/test_helper.exs:1: (file)
Am I missing something? Would anyone have more information about how to use LoggerBackends?