test: Also do self-debug test with DAP server

This test tried, but didn't exhibit the bug in #294.
It is a good end-to-end test nonetheless, so we should keep it.

Author: alt-romes

haskell-debugger.cabal

@@ -243,7 +243,8 @@ test-suite haskell-debugger-test
                       Test.Integration.Stdout,
                       Test.Integration.Conditional,
                       Test.Integration.Evaluate,
-                      Test.Integration.StackTrace
+                      Test.Integration.StackTrace,
+                      Test.Integration.SelfDebug
     build-depends:
         base >=4.14,
         async,

test/haskell/Main.hs

@@ -38,6 +38,7 @@ import Test.Integration.Stdout (stdoutTests)
 import Test.Integration.Conditional (conditionalTests)
 import Test.Integration.Evaluate (evaluateTests)
 import Test.Integration.StackTrace (stackTraceTests)
+import Test.Integration.SelfDebug (selfDebugTests)
 import Test.Utils
 import qualified Data.Char as C
 import qualified Data.Text as T
@@ -102,6 +103,7 @@ unitTests =
   , conditionalTests
   , evaluateTests
   , stackTraceTests
+  , selfDebugTests
   ]
 
 -- | Receives as an argument the path to the @*.hdb-test@ which contains the

test/haskell/Test/Integration/SelfDebug.hs

@@ -0,0 +1,55 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Test.Integration.SelfDebug (selfDebugTests) where
+
+import Control.Monad.IO.Class (liftIO)
+import Data.Aeson
+import System.Directory (getCurrentDirectory)
+import Test.DAP
+import Test.DAP.Messages.Parser (Event(..))
+import Test.Tasty
+import Test.Tasty.HUnit
+import qualified DAP
+import DAP.Types (StoppedEvent(..))
+#ifdef mingw32_HOST_OS
+import Test.Tasty.ExpectedFailure
+#endif
+
+selfDebugTests :: TestTree
+selfDebugTests =
+#ifdef mingw32_HOST_OS
+  ignoreTestBecause "Needs to be fixed for Windows (#199)" $
+#endif
+  testGroup "DAP.Integration.SelfDebug"
+    [ testCase "debug the debugger itself via DAP" selfDebugDAPTest
+    ]
+
+selfDebugDAPTest :: Assertion
+selfDebugDAPTest = do
+  projectRoot <- getCurrentDirectory -- Self-debug test copies project root to temp dir
+  withTestDAPServer projectRoot [] $ \test_dir server -> do
+    withTestDAPServerClient server $ do
+      let cfg = LaunchConfig
+            { lcProjectRoot = test_dir
+            , lcEntryFile = Just "hdb/Main.hs"
+            , lcEntryPoint = Just "main"
+            , lcEntryArgs = ["cli", "test/golden/self-debug-cli/Main.hs"]
+            , lcExtraGhcArgs = []
+            , lcInternalInterpreter = Nothing
+            }
+
+      _ <- sync $ launchWith cfg
+      waitFiltering_ EventTy "initialized"
+
+      _ <- sync $ setFunctionBreakpointsRequest @_ @Value $ object
+        [ "breakpoints" .= [ object [ "name" .= ("runDebugger" :: String) ] ] ]
+
+      _ <- sync configurationDone
+
+      Event{eventBody = Just StoppedEvent{stoppedEventReason = reason}}
+        <- waitFiltering EventTy "stopped"
+      liftIO $ assertEqual "expected breakpoint stop"
+        reason DAP.StoppedEventReasonBreakpoint
+          -- fixme: should we reply with StoppedEventReasonFunctionBreakpoint instead?
+
+      disconnect