use SIGINT handler in template / docs

CHANGELOG.md

@@ -38,6 +38,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ### Changed
 
+- Running plutip servers attaches on SIGINT handlers and therefore node will not exit by default. ([#1231](https://github.com/Plutonomicon/cardano-transaction-lib/pull/1231)).
+
 ### Removed
 
 ### Fixed

doc/plutip-testing.md

@@ -183,3 +183,7 @@ let
 Although stake keys serve no real purpose in plutip context, they allow to use base addresses, and thus allow to have the same code for plutip testing, in-browser tests and production.
 
 Note that CTL re-distributes tADA from payment key-only ("enterprise") addresses to base addresses, which requires a few transactions before the test can be run. Plutip can currently handle only enterprise addreses (see [this issue](https://github.com/mlabs-haskell/plutip/issues/103)).
+
+## custom SIGINT handlers
+
+SIGINT does not exit the node process when running a plutip server. Instead, we use a custom handler listening on SIGINT that cancels the fiber. This has the same effect in the end: The process will exit when there are no more possible events, one of them being our custom `cleanupOnSigint` that gets attached and detached to every plutip cluster. We avoid exiting on SIGINT so that multiple plutip servers with different port configs can be run in parallel.

src/Contract/Test/Utils.purs

@@ -632,6 +632,8 @@ checkTxHasMetadata txHash =
 
 foreign import exitCode :: Int -> Effect Unit
 
+-- | attaches a custom handler on SIGINt to kill the fiber.
+-- | see `doc/plutip-testing#custom-SIGINT-handlers`
 interruptOnSignal :: forall a. Signal -> Fiber a -> Effect Unit
 interruptOnSignal signal fiber = Process.onSignal signal do
   launchAff_ do

templates/ctl-scaffold/flake.nix

@@ -10,7 +10,7 @@
       type = "github";
       owner = "Plutonomicon";
       repo = "cardano-transaction-lib";
-      rev = "a01a9409af204df835e97150bcdefe543910f2f9";
+      rev = "3ffc2c7f6edce0d2b838a226eb3d8ed3a8a63484";
     };
     # To use the same version of `nixpkgs` as we do
     nixpkgs.follows = "ctl/nixpkgs";

templates/ctl-scaffold/packages.dhall

@@ -367,7 +367,7 @@ let additions =
           , "variant"
           ]
         , repo = "https://github.com/Plutonomicon/cardano-transaction-lib.git"
-        , version = "a01a9409af204df835e97150bcdefe543910f2f9"
+        , version = "3ffc2c7f6edce0d2b838a226eb3d8ed3a8a63484"
         }
       }
 

templates/ctl-scaffold/spago.dhall

@@ -9,6 +9,7 @@ You can edit this file as you like.
   , "cardano-transaction-lib"
   , "effect"
   , "ordered-collections"
+  , "posix-types"
   , "prelude"
   , "uint"
   ]

templates/ctl-scaffold/test/Main.purs

@@ -5,24 +5,27 @@ module Test.Scaffold.Main (main) where
 import Contract.Prelude
 
 import Contract.Config as Contract.Config
-import Contract.Monad as Contract.Monad
 import Contract.Test.Plutip as Contract.Test.Plutip
+import Contract.Test.Utils (exitCode, interruptOnSignal)
 import Contract.Wallet as Contract.Wallet
 import Data.BigInt as BigInt
+import Data.Posix.Signal (Signal(SIGINT))
 import Data.UInt as UInt
+import Effect.Aff (cancelWith, effectCanceler, launchAff)
 import Scaffold as Scaffold
 
 main :: Effect Unit
-main = Contract.Monad.launchAff_ $ do
-  let
-    distribution :: Contract.Test.Plutip.InitialUTxOs
-    distribution =
-      [ BigInt.fromInt 5_000_000
-      , BigInt.fromInt 2_000_000_000
-      ]
-  Contract.Test.Plutip.runPlutipContract config distribution \alice ->
-    Contract.Wallet.withKeyWallet alice $ do
-      Scaffold.contract
+main = interruptOnSignal SIGINT =<< launchAff do
+  flip cancelWith (effectCanceler (exitCode 1)) do
+    let
+      distribution :: Contract.Test.Plutip.InitialUTxOs
+      distribution =
+        [ BigInt.fromInt 5_000_000
+        , BigInt.fromInt 2_000_000_000
+        ]
+    Contract.Test.Plutip.runPlutipContract config distribution \alice ->
+      Contract.Wallet.withKeyWallet alice $ do
+        Scaffold.contract
 
 config :: Contract.Test.Plutip.PlutipConfig
 config =