Test Node.js event loop exit prevention

Author: jamesdbrock

spago-dev.dhall

@@ -20,6 +20,7 @@ conf //
   , "console"
   , "partial"
   , "unsafe-coerce"
+  , "control"
   ]
 , packages = packages_dev
 }

test/Main4.purs

@@ -0,0 +1,43 @@
+-- | How to test:
+-- |
+-- | ```
+-- | spago -x spago-dev.dhall test --main Test4
+-- | ```
+-- |
+-- | This is a test that `readSome` will prevent the Node.js event
+-- | loop from exiting.
+module Test4 where
+
+import Prelude
+
+import Control.Alt (alt)
+import Data.Either (Either(..))
+import Effect (Effect)
+import Effect.Aff (Error, Milliseconds(..), delay, parallel, runAff_, sequential)
+import Effect.Class.Console as Console
+import Node.Process (stdin)
+import Node.Stream.Aff (readSome)
+import Partial.Unsafe (unsafePartial)
+import Test.Spec (describe, it)
+import Test.Spec.Reporter (consoleReporter)
+import Test.Spec.Runner (runSpec)
+import Unsafe.Coerce (unsafeCoerce)
+
+completion :: Either Error (Effect Unit) -> Effect Unit
+completion = case _ of
+  Left e -> Console.error (unsafeCoerce e)
+  Right f -> f
+
+
+main :: Effect Unit
+main = unsafePartial $ do
+  runAff_ completion do
+    runSpec [consoleReporter] do
+      describe "Node.Stream.Aff" do
+        it "reads 1" do
+          sequential $ alt
+            do
+              parallel $ void $ readSome stdin
+            do
+              parallel $ delay (Milliseconds 500.0)
+    pure (pure unit)