fix: logWithExit_ should exit on Just

Changelog.md

@@ -1,5 +1,9 @@
 # Spectrometer Changelog
 
+## Unreleased
+
+- Fixes an issue where some `fossa` commands (including `fossa test`) would exit non-zero on success ([#278](https://github.com/fossas/spectrometer/pull/278)).
+
 ## v2.10.1
 
 - Fixes an issue where `fossa container analyze` returned 0 exit code on failure ([#275](https://github.com/fossas/spectrometer/pull/275))

src/Control/Carrier/Diagnostics.hs

@@ -29,7 +29,7 @@ import Control.Monad.Trans
 import Data.Monoid (Endo (..))
 import Data.Text (Text)
 import Effect.Logger
-import System.Exit (exitFailure)
+import System.Exit (exitFailure, exitSuccess)
 
 newtype DiagnosticsC m a = DiagnosticsC {runDiagnosticsC :: ReaderC [Text] (ErrorC SomeDiagnostic (WriterC (Endo [SomeDiagnostic]) m)) a}
   deriving (Functor, Applicative, Monad, MonadIO)
@@ -52,7 +52,7 @@ logDiagnostic diag = do
 -- | Exits with non-zero if the result is a failure.
 -- | Useful for setting up diagnostics from CLI entry points.
 logWithExit_ :: (Has (Lift IO) sig m, Has Logger sig m) => DiagnosticsC m () -> m ()
-logWithExit_ diag = logDiagnostic diag >>= maybe (sendIO exitFailure) pure
+logWithExit_ diag = logDiagnostic diag >>= maybe (sendIO exitFailure) (const (sendIO exitSuccess))
 
 runDiagnostics :: Applicative m => DiagnosticsC m a -> m (Either FailureBundle a)
 runDiagnostics = fmap bundle . runWriter (\w a -> pure (appEndo w [], a)) . runError @SomeDiagnostic . runReader [] . runDiagnosticsC