From 282387f6cbd4be07041c5402c34d72945f1357ed Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sat, 3 Jul 2021 22:00:28 +0800
Subject: [PATCH 01/11] Eval plugin: support ghc 9.0.1

---
 cabal-ghc901.project                          |  2 +-
 .../src/Ide/Plugin/Eval/CodeLens.hs           | 59 ++++++++++++-------
 stack-9.0.1.yaml                              |  1 -
 3 files changed, 39 insertions(+), 23 deletions(-)

diff --git a/cabal-ghc901.project b/cabal-ghc901.project
index c6242f007a..52215d3521 100644
--- a/cabal-ghc901.project
+++ b/cabal-ghc901.project
@@ -81,7 +81,7 @@ index-state: 2021-06-30T16:00:00Z
 
 constraints:
     -- These plugins doesn't work on GHC9 yet
-    haskell-language-server -brittany -class -eval -fourmolu -ormolu -splice -stylishhaskell -tactic -refineImports
+    haskell-language-server -brittany -class -fourmolu -ormolu -splice -stylishhaskell -tactic -refineImports
 
 
 allow-newer:
diff --git a/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs b/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs
index c6b418372a..5e920cdb09 100644
--- a/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs
+++ b/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs
@@ -152,23 +152,29 @@ import           System.IO                            (hClose)
 import           UnliftIO.Temporary                   (withSystemTempFile)
 import           Util                                 (OverridingBool (Never))
 
-
+import           IfaceSyn                             (showToHeader)
+import           PprTyThing                           (pprTyThingInContext, pprTypeForUser)
 #if MIN_VERSION_ghc(9,0,0)
-import           GHC.Parser.Annotation                (ApiAnns (apiAnnComments))
+import           GHC.Parser.Annotation                (ApiAnns (apiAnnRogueComments))
+import           GHC.Parser.Lexer                     (mkParserFlags)
+import           GHC.Driver.Ways                      (hostFullWays,
+                                                       wayGeneralFlags,
+                                                       wayUnsetGeneralFlags)
+import           GHC.Types.SrcLoc                     (UnhelpfulSpanReason(UnhelpfulInteractive))
 #else
 import           GhcPlugins                           (interpWays, updateWays,
                                                        wayGeneralFlags,
                                                        wayUnsetGeneralFlags)
-import           IfaceSyn                             (showToHeader)
-import           PprTyThing                           (pprTyThingInContext)
 #endif
 
 #if MIN_VERSION_ghc(9,0,0)
 pattern RealSrcSpanAlready :: SrcLoc.RealSrcSpan -> SrcLoc.RealSrcSpan
 pattern RealSrcSpanAlready x = x
+apiAnnComments' :: SrcLoc.ApiAnns -> [SrcLoc.RealLocated AnnotationComment]
+apiAnnComments' = apiAnnRogueComments
 #else
-apiAnnComments :: SrcLoc.ApiAnns -> Map.Map SrcSpan [SrcLoc.Located AnnotationComment]
-apiAnnComments = snd
+apiAnnComments' :: SrcLoc.ApiAnns -> [SrcLoc.Located AnnotationComment]
+apiAnnComments' = concat . Map.elems . snd
 
 pattern RealSrcSpanAlready :: SrcLoc.RealSrcSpan -> SrcSpan
 pattern RealSrcSpanAlready x = SrcLoc.RealSrcSpan x
@@ -190,9 +196,9 @@ codeLens st plId CodeLensParams{_textDocument} =
                     isLHS = isLiterate fp
                 dbg "fp" fp
                 (ParsedModule{..}, posMap) <- liftIO $
-                    runAction "parsed" st $ useWithStale_ GetParsedModuleWithComments nfp
-                let comments = foldMap
-                        ( foldMap $ \case
+                    runAction "eval.GetParsedModuleWithComments" st $ useWithStale_ GetParsedModuleWithComments nfp
+                let comments =
+                         foldMap (\case
                             L (RealSrcSpanAlready real) bdy
                                 | unpackFS (srcSpanFile real) ==
                                     fromNormalizedFilePath nfp
@@ -210,16 +216,15 @@ codeLens st plId CodeLensParams{_textDocument} =
                                         _ -> mempty
                             _ -> mempty
                         )
-                        $ apiAnnComments pm_annotations
+                        $ apiAnnComments' pm_annotations
                 dbg "excluded comments" $ show $  DL.toList $
-                    foldMap
-                    (foldMap $ \(L a b) ->
+                    foldMap (\(L a b) ->
                         case b of
                             AnnLineComment{}  -> mempty
                             AnnBlockComment{} -> mempty
                             _                 -> DL.singleton (a, b)
                     )
-                    $ apiAnnComments pm_annotations
+                    $ apiAnnComments' pm_annotations
                 dbg "comments" $ show comments
 
                 -- Extract tests from source code
@@ -546,7 +551,7 @@ evals (st, fp) df stmts = do
             eans <-
                 liftIO $ try @GhcException $
                 parseDynamicFlagsCmdLine ndf
-                (map (L $ UnhelpfulSpan "<interactive>") flags)
+                (map (L $ UnhelpfulSpan unhelpfulReason) flags)
             dbg "parsed flags" $ eans
               <&> (_1 %~ showDynFlags >>> _3 %~ map warnMsg)
             case eans of
@@ -572,7 +577,7 @@ evals (st, fp) df stmts = do
           Just (cmd, arg) <- parseGhciLikeCmd $ T.pack stmt =
             evalGhciLikeCmd cmd arg
         | -- A statement
-          isStmt df stmt =
+          isStmt pf stmt =
             do
                 dbg "{STMT " stmt
                 res <- exec stmt l
@@ -582,7 +587,7 @@ evals (st, fp) df stmts = do
                 dbg "STMT} -> " r
                 return r
         | -- An import
-          isImport df stmt =
+          isImport pf stmt =
             do
                 dbg "{IMPORT " stmt
                 _ <- addImport stmt
@@ -593,6 +598,13 @@ evals (st, fp) df stmts = do
                 dbg "{DECL " stmt
                 void $ runDecls stmt
                 return Nothing
+#if !MIN_VERSION_ghc(9,0,0)
+    pf = df
+    unhelpfulReason = "<interactive>"
+#else
+    pf = mkParserFlags df
+    unhelpfulReason = UnhelpfulInteractive
+#endif
     exec stmt l =
         let opts = execOptions{execSourceFile = fp, execLineNumber = l}
          in myExecStmt stmt opts
@@ -752,7 +764,7 @@ doTypeCmd :: DynFlags -> Text -> Ghc (Maybe Text)
 doTypeCmd dflags arg = do
     let (emod, expr) = parseExprMode arg
     ty <- exprType emod $ T.unpack expr
-    let rawType = T.strip $ T.pack $ showSDoc dflags $ ppr ty
+    let rawType = T.strip $ T.pack $ showSDoc dflags $ pprTypeForUser ty
         broken = T.any (\c -> c == '\r' || c == '\n') rawType
     pure $
         Just $
@@ -761,7 +773,7 @@ doTypeCmd dflags arg = do
                     T.pack $
                         showSDoc dflags $
                             text (T.unpack expr)
-                                $$ nest 2 ("::" <+> ppr ty)
+                                $$ nest 2 ("::" <+> pprTypeForUser ty)
                 else expr <> " :: " <> rawType <> "\n"
 
 parseExprMode :: Text -> (TcRnExprMode, T.Text)
@@ -804,13 +816,18 @@ setupDynFlagsForGHCiLike env dflags = do
                 , ghcLink = LinkInMemory
                 }
         platform = targetPlatform dflags3
-        dflags3a = updateWays $ dflags3{ways = interpWays}
+#if MIN_VERSION_ghc(9,0,0)
+        evalWays = hostFullWays
+#else
+        evalWays = interpWays
+#endif
+        dflags3a = dflags3{ways = evalWays}
         dflags3b =
             foldl gopt_set dflags3a $
-                concatMap (wayGeneralFlags platform) interpWays
+                concatMap (wayGeneralFlags platform) evalWays
         dflags3c =
             foldl gopt_unset dflags3b $
-                concatMap (wayUnsetGeneralFlags platform) interpWays
+                concatMap (wayUnsetGeneralFlags platform) evalWays
         dflags4 =
             dflags3c
                 `gopt_set` Opt_ImplicitImportQualified
diff --git a/stack-9.0.1.yaml b/stack-9.0.1.yaml
index c335fa7947..25d616c129 100644
--- a/stack-9.0.1.yaml
+++ b/stack-9.0.1.yaml
@@ -105,7 +105,6 @@ configure-options:
 flags:
   haskell-language-server:
     pedantic: true
-    eval: false
     class: false
     splice: false
     refineImports: false

From 02b692cc2b769fd70cc46ec068e8c52bd8d8a5ce Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 10:03:56 +0800
Subject: [PATCH 02/11] Update CI and stack

---
 .github/workflows/test.yml | 2 +-
 stack-9.0.1.yaml           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 63c4a8f7bb..1c902b0c97 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -170,7 +170,7 @@ jobs:
         name: Test hls-class-plugin
         run: cabal test hls-class-plugin --test-options="-j1 --rerun-update" || cabal test hls-class-plugin --test-options="-j1 --rerun" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-class-plugin --test-options="-j1 --rerun"
 
-      - if: ${{ needs.pre_job.outputs.should_skip != 'true' && matrix.test && matrix.ghc != '9.0.1' }}
+      - if: ${{ needs.pre_job.outputs.should_skip != 'true' && matrix.test }}
         name: Test hls-eval-plugin
         run: cabal test hls-eval-plugin --test-options="-j1 --rerun-update" || cabal test hls-eval-plugin --test-options="-j1 --rerun" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-eval-plugin --test-options="-j1 --rerun"
 
diff --git a/stack-9.0.1.yaml b/stack-9.0.1.yaml
index 25d616c129..8facf065b1 100644
--- a/stack-9.0.1.yaml
+++ b/stack-9.0.1.yaml
@@ -11,7 +11,7 @@ packages:
   # - ./shake-bench
   # - ./plugins/hls-class-plugin
   - ./plugins/hls-haddock-comments-plugin
-  # - ./plugins/hls-eval-plugin
+  - ./plugins/hls-eval-plugin
   - ./plugins/hls-explicit-imports-plugin
   # - ./plugins/hls-refine-imports-plugin
   - ./plugins/hls-hlint-plugin

From f8ebeac67087a99da4ea6833d25dbfb710a3be42 Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 10:04:44 +0800
Subject: [PATCH 03/11] Use pprTypeForUser for printing kinds

---
 plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs b/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs
index 5e920cdb09..28c867a95e 100644
--- a/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs
+++ b/plugins/hls-eval-plugin/src/Ide/Plugin/Eval/CodeLens.hs
@@ -751,13 +751,13 @@ doKindCmd :: Bool -> DynFlags -> Text -> Ghc (Maybe Text)
 doKindCmd False df arg = do
     let input = T.strip arg
     (_, kind) <- typeKind False $ T.unpack input
-    let kindText = text (T.unpack input) <+> "::" <+> ppr kind
+    let kindText = text (T.unpack input) <+> "::" <+> pprTypeForUser kind
     pure $ Just $ T.pack (showSDoc df kindText)
 doKindCmd True df arg = do
     let input = T.strip arg
     (ty, kind) <- typeKind True $ T.unpack input
-    let kindDoc = text (T.unpack input) <+> "::" <+> ppr kind
-        tyDoc = "=" <+> ppr ty
+    let kindDoc = text (T.unpack input) <+> "::" <+> pprTypeForUser kind
+        tyDoc = "=" <+> pprTypeForUser ty
     pure $ Just $ T.pack (showSDoc df $ kindDoc $$ tyDoc)
 
 doTypeCmd :: DynFlags -> Text -> Ghc (Maybe Text)

From a9e218dcbbded36f93793a0d8a619c36bd4ce46a Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 10:05:33 +0800
Subject: [PATCH 04/11] test: remove forall

---
 .../testdata/TSameDefaultLanguageExtensionsAsGhci.expected.hs   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/hls-eval-plugin/test/testdata/TSameDefaultLanguageExtensionsAsGhci.expected.hs b/plugins/hls-eval-plugin/test/testdata/TSameDefaultLanguageExtensionsAsGhci.expected.hs
index dad95db872..ac69b2a0ef 100644
--- a/plugins/hls-eval-plugin/test/testdata/TSameDefaultLanguageExtensionsAsGhci.expected.hs
+++ b/plugins/hls-eval-plugin/test/testdata/TSameDefaultLanguageExtensionsAsGhci.expected.hs
@@ -24,4 +24,4 @@ It therefore suffices to test for ExtendedDefaultRules and NoMonomorphismRestric
 
 -- >>> plus = (+)
 -- >>> :t plus
--- plus :: forall a. Num a => a -> a -> a
+-- plus :: Num a => a -> a -> a

From 4f4490b63619cc13f77057ee14b9b0d01f85f4c5 Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 10:07:54 +0800
Subject: [PATCH 05/11] test: [Char] -> String

---
 plugins/hls-eval-plugin/test/testdata/T8.expected.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/hls-eval-plugin/test/testdata/T8.expected.hs b/plugins/hls-eval-plugin/test/testdata/T8.expected.hs
index 2089d3d78f..94db41d104 100644
--- a/plugins/hls-eval-plugin/test/testdata/T8.expected.hs
+++ b/plugins/hls-eval-plugin/test/testdata/T8.expected.hs
@@ -5,7 +5,7 @@ module T8 where
 -- Variable not in scope: noFunctionWithThisName
 
 -- >>> "a" + "bc"
--- No instance for (Num [Char]) arising from a use of ‘+’
+-- No instance for (Num String) arising from a use of ‘+’
 
 -- >>> "
 -- lexical error in string/character literal at end of input

From 1a8fa2c277920e9a8c9030501ebcfbdc1daf7440 Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 10:23:23 +0800
Subject: [PATCH 06/11] test: update forall

---
 .../test/testdata/T21.expected.hs               |  2 +-
 .../test/testdata/T23.expected.hs               |  2 +-
 .../test/testdata/TFlags.expected.hs            | 17 ++++++-----------
 plugins/hls-eval-plugin/test/testdata/TFlags.hs | 14 ++++----------
 4 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/plugins/hls-eval-plugin/test/testdata/T21.expected.hs b/plugins/hls-eval-plugin/test/testdata/T21.expected.hs
index 5ffcc3906d..6e23213474 100644
--- a/plugins/hls-eval-plugin/test/testdata/T21.expected.hs
+++ b/plugins/hls-eval-plugin/test/testdata/T21.expected.hs
@@ -11,6 +11,6 @@ fun _ _ _ = ()
 
 -- >>> :type fun
 -- fun
---   :: forall k1 (k2 :: Nat) (n :: Nat) (a :: k1).
+--   :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}.
 --      (KnownNat k2, KnownNat n, Typeable a) =>
 --      Proxy k2 -> Proxy n -> Proxy a -> ()
diff --git a/plugins/hls-eval-plugin/test/testdata/T23.expected.hs b/plugins/hls-eval-plugin/test/testdata/T23.expected.hs
index 3039ca8a8c..dbe7fa6ff0 100644
--- a/plugins/hls-eval-plugin/test/testdata/T23.expected.hs
+++ b/plugins/hls-eval-plugin/test/testdata/T23.expected.hs
@@ -10,6 +10,6 @@ f :: forall k n a. (KnownNat k, KnownNat n, Typeable a)
 f _ _ _ = ()
 
 -- >>> :type f
--- f :: forall k1 (k2 :: Nat) (n :: Nat) (a :: k1).
+-- f :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}.
 --      (KnownNat k2, KnownNat n, Typeable a) =>
 --      Proxy k2 -> Proxy n -> Proxy a -> ()
diff --git a/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs b/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs
index 9d6196e5bf..b15a988534 100644
--- a/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs
+++ b/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs
@@ -51,14 +51,14 @@ It still works
 
 {- -fprint-* families
 
->>> import Data.Proxy
->>> :set -XPolyKinds
->>> :t Proxy
-Proxy :: forall k (t :: k). Proxy t
+>>> :t id
+id :: a -> a
+
 
 >>> :set -fprint-explicit-foralls
->>> :t Proxy
-Proxy :: forall {k} {t :: k}. Proxy t
+>>> :t id
+id :: forall {a}. a -> a
+
 -}
 
 {- Invalid option/flags are reported, but valid ones will be reflected
@@ -68,9 +68,4 @@ Proxy :: forall {k} {t :: k}. Proxy t
     -XDatatypeContexts is deprecated: It was widely considered a misfeature, and has been removed from the Haskell language.
 Some flags have not been recognized: -XAbsent, -XWrong, -fprint-nothing-at-all
 
-Still, Rank2Types is enabled, as in GHCi:
-
->>> f = const 42 :: (forall x. x) -> Int
->>> f undefined
-42
 -}
diff --git a/plugins/hls-eval-plugin/test/testdata/TFlags.hs b/plugins/hls-eval-plugin/test/testdata/TFlags.hs
index a821ea4ec1..c8b49a6e2a 100644
--- a/plugins/hls-eval-plugin/test/testdata/TFlags.hs
+++ b/plugins/hls-eval-plugin/test/testdata/TFlags.hs
@@ -47,22 +47,16 @@ It still works
 
 {- -fprint-* families
 
->>> import Data.Proxy
->>> :set -XPolyKinds
->>> :t Proxy
-Proxy :: forall k (t :: k). Proxy t
+>>> :t id
+
 
 >>> :set -fprint-explicit-foralls
->>> :t Proxy
-Proxy :: forall {k} {t :: k}. Proxy t
+>>> :t id
+
 -}
 
 {- Invalid option/flags are reported, but valid ones will be reflected
 
 >>> :set -XRank2Types -XAbsent -XDatatypeContexts -XWrong -fprint-nothing-at-all
 
-Still, Rank2Types is enabled, as in GHCi:
-
->>> f = const 42 :: (forall x. x) -> Int
->>> f undefined
 -}

From 2cddd7666df3c903a7a28cc21e085d655d81e720 Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 10:35:09 +0800
Subject: [PATCH 07/11] Keep tests only for GHC 9

---
 .github/workflows/test.yml           | 2 +-
 hls-test-utils/src/Test/Hls/Util.hs  | 5 ++++-
 plugins/hls-eval-plugin/test/Main.hs | 6 +++++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1c902b0c97..b3affa8b1f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -170,7 +170,7 @@ jobs:
         name: Test hls-class-plugin
         run: cabal test hls-class-plugin --test-options="-j1 --rerun-update" || cabal test hls-class-plugin --test-options="-j1 --rerun" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-class-plugin --test-options="-j1 --rerun"
 
-      - if: ${{ needs.pre_job.outputs.should_skip != 'true' && matrix.test }}
+      - if: ${{ needs.pre_job.outputs.should_skip != 'true' && matrix.test && matrix.ghc == '9.0.1' }}
         name: Test hls-eval-plugin
         run: cabal test hls-eval-plugin --test-options="-j1 --rerun-update" || cabal test hls-eval-plugin --test-options="-j1 --rerun" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-eval-plugin --test-options="-j1 --rerun"
 
diff --git a/hls-test-utils/src/Test/Hls/Util.hs b/hls-test-utils/src/Test/Hls/Util.hs
index 182a2500c5..e54f018e33 100644
--- a/hls-test-utils/src/Test/Hls/Util.hs
+++ b/hls-test-utils/src/Test/Hls/Util.hs
@@ -112,10 +112,13 @@ data GhcVersion
   | GHC88
   | GHC86
   | GHC84
+  | GHC901
   deriving (Eq,Show)
 
 ghcVersion :: GhcVersion
-#if (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,10,0,0)))
+#if (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(9,0,1,0)))
+ghcVersion = GHC901
+#elif (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,10,0,0)))
 ghcVersion = GHC810
 #elif (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,8,0,0)))
 ghcVersion = GHC88
diff --git a/plugins/hls-eval-plugin/test/Main.hs b/plugins/hls-eval-plugin/test/Main.hs
index 03972a96c0..4264391742 100644
--- a/plugins/hls-eval-plugin/test/Main.hs
+++ b/plugins/hls-eval-plugin/test/Main.hs
@@ -20,7 +20,11 @@ import           System.FilePath         ((</>))
 import           Test.Hls
 
 main :: IO ()
-main = defaultTestRunner tests
+main = defaultTestRunner $ if ghcVersion == GHC901 then tests else dummyTestCase
+
+-- | Now we only maintain test cases for GHC 9.0.1
+dummyTestCase :: TestTree
+dummyTestCase = testCase "Tests are skipped before GHC 9.0.1" $ pure ()
 
 evalPlugin :: PluginDescriptor IdeState
 evalPlugin = Eval.descriptor "eval"

From 7bad4dbb30646f43c091974860aa9cb58669b04a Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 14:54:29 +0800
Subject: [PATCH 08/11] Update nix and CI

---
 .github/workflows/test.yml           |  2 +-
 configuration-ghc-901.nix            |  2 --
 plugins/hls-eval-plugin/test/Main.hs | 10 ++++++----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index b3affa8b1f..34526ab0d5 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -170,7 +170,7 @@ jobs:
         name: Test hls-class-plugin
         run: cabal test hls-class-plugin --test-options="-j1 --rerun-update" || cabal test hls-class-plugin --test-options="-j1 --rerun" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-class-plugin --test-options="-j1 --rerun"
 
-      - if: ${{ needs.pre_job.outputs.should_skip != 'true' && matrix.test && matrix.ghc == '9.0.1' }}
+      - if: ${{ needs.pre_job.outputs.should_skip != 'true' && matrix.test && matrix.ghc }}
         name: Test hls-eval-plugin
         run: cabal test hls-eval-plugin --test-options="-j1 --rerun-update" || cabal test hls-eval-plugin --test-options="-j1 --rerun" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-eval-plugin --test-options="-j1 --rerun"
 
diff --git a/configuration-ghc-901.nix b/configuration-ghc-901.nix
index 9c74864608..1a59bff132 100644
--- a/configuration-ghc-901.nix
+++ b/configuration-ghc-901.nix
@@ -9,7 +9,6 @@ let
     "hls-fourmolu-plugin"
     "hls-splice-plugin"
     "hls-ormolu-plugin"
-    "hls-eval-plugin"
     "hls-class-plugin"
     "hls-refine-imports-plugin"
   ];
@@ -106,7 +105,6 @@ let
         (pkgs.lib.concatStringsSep " " [
           "-f-brittany"
           "-f-class"
-          "-f-eval"
           "-f-fourmolu"
           "-f-ormolu"
           "-f-splice"
diff --git a/plugins/hls-eval-plugin/test/Main.hs b/plugins/hls-eval-plugin/test/Main.hs
index 4264391742..2098526fcd 100644
--- a/plugins/hls-eval-plugin/test/Main.hs
+++ b/plugins/hls-eval-plugin/test/Main.hs
@@ -20,11 +20,13 @@ import           System.FilePath         ((</>))
 import           Test.Hls
 
 main :: IO ()
-main = defaultTestRunner $ if ghcVersion == GHC901 then tests else dummyTestCase
+main = defaultTestRunner $ ignore tests
 
--- | Now we only maintain test cases for GHC 9.0.1
-dummyTestCase :: TestTree
-dummyTestCase = testCase "Tests are skipped before GHC 9.0.1" $ pure ()
+ignore :: TestTree -> TestTree
+ignore =
+    if ghcVersion == GHC901
+       then id
+       else ignoreTestBecause "Eval plugin tests are enabled for GHC 9.0.1"
 
 evalPlugin :: PluginDescriptor IdeState
 evalPlugin = Eval.descriptor "eval"

From 9489c226a1f45799d2dade9318e4e072788fec8f Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 15:02:16 +0800
Subject: [PATCH 09/11] Mark one hlint test as known broken

---
 test/functional/FunctionalCodeAction.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/functional/FunctionalCodeAction.hs b/test/functional/FunctionalCodeAction.hs
index 13dd7eca67..877987505c 100644
--- a/test/functional/FunctionalCodeAction.hs
+++ b/test/functional/FunctionalCodeAction.hs
@@ -151,7 +151,7 @@ hlintTests = testGroup "hlint suggestions" [
         doc <- openDoc "ApplyRefact4.hs" "haskell"
         expectNoMoreDiagnostics 3 doc "hlint"
 
-    , knownBrokenForGhcVersions [GHC810] "hlint plugin doesn't honour HLINT annotations (#838)" $
+    , knownBrokenForGhcVersions [GHC810, GHC901] "hlint plugin doesn't honour HLINT annotations (#838)" $
       testCase "hlint diagnostics ignore hints honouring HLINT annotations" $ runHlintSession "" $ do
         doc <- openDoc "ApplyRefact5.hs" "haskell"
         expectNoMoreDiagnostics 3 doc "hlint"

From d89b418694e3c076ff1306c7ee8d9a70594f128a Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Sun, 4 Jul 2021 23:08:14 +0800
Subject: [PATCH 10/11] Re-enable tests for other ghc versions

---
 plugins/hls-eval-plugin/hls-eval-plugin.cabal |  7 +--
 plugins/hls-eval-plugin/test/Main.hs          | 53 +++++++++++++++----
 .../test/testdata/T21.expected.hs             | 16 ------
 plugins/hls-eval-plugin/test/testdata/T21.hs  |  1 -
 .../test/testdata/T23.expected.hs             | 15 ------
 plugins/hls-eval-plugin/test/testdata/T23.hs  |  1 -
 .../test/testdata/T8.expected.hs              | 14 -----
 plugins/hls-eval-plugin/test/testdata/T8.hs   | 10 +---
 .../test/testdata/TFlags.expected.hs          | 11 ----
 .../hls-eval-plugin/test/testdata/TFlags.hs   |  9 ----
 10 files changed, 48 insertions(+), 89 deletions(-)
 delete mode 100644 plugins/hls-eval-plugin/test/testdata/T21.expected.hs
 delete mode 100644 plugins/hls-eval-plugin/test/testdata/T23.expected.hs
 delete mode 100644 plugins/hls-eval-plugin/test/testdata/T8.expected.hs

diff --git a/plugins/hls-eval-plugin/hls-eval-plugin.cabal b/plugins/hls-eval-plugin/hls-eval-plugin.cabal
index ff901f7bef..2be1a9dd71 100644
--- a/plugins/hls-eval-plugin/hls-eval-plugin.cabal
+++ b/plugins/hls-eval-plugin/hls-eval-plugin.cabal
@@ -19,13 +19,13 @@ build-type:         Simple
 extra-source-files:
   LICENSE
   README.md
+  test/cabal.project
+  test/info-util/*.cabal
+  test/info-util/*.hs
   test/testdata/*.cabal
   test/testdata/*.hs
   test/testdata/*.lhs
   test/testdata/*.yaml
-  test/info-util/*.cabal
-  test/info-util/*.hs
-  test/cabal.project
 
 flag pedantic
   description: Enable -Werror
@@ -110,3 +110,4 @@ test-suite tests
     , hls-test-utils   ^>=1.0
     , lens
     , lsp-types
+    , text
diff --git a/plugins/hls-eval-plugin/test/Main.hs b/plugins/hls-eval-plugin/test/Main.hs
index 2098526fcd..2933a2ca00 100644
--- a/plugins/hls-eval-plugin/test/Main.hs
+++ b/plugins/hls-eval-plugin/test/Main.hs
@@ -18,15 +18,10 @@ import           Ide.Plugin.Eval.Types   (EvalParams (..), Section (..),
 import           Language.LSP.Types.Lens (arguments, command, range, title)
 import           System.FilePath         ((</>))
 import           Test.Hls
+import qualified Data.Text as T
 
 main :: IO ()
-main = defaultTestRunner $ ignore tests
-
-ignore :: TestTree -> TestTree
-ignore =
-    if ghcVersion == GHC901
-       then id
-       else ignoreTestBecause "Eval plugin tests are enabled for GHC 9.0.1"
+main = defaultTestRunner tests
 
 evalPlugin :: PluginDescriptor IdeState
 evalPlugin = Eval.descriptor "eval"
@@ -67,7 +62,14 @@ tests =
   , goldenWithEval "Refresh an evaluation" "T5" "hs"
   , goldenWithEval "Refresh an evaluation w/ lets" "T6" "hs"
   , goldenWithEval "Refresh a multiline evaluation" "T7" "hs"
-  , goldenWithEval "Semantic and Lexical errors are reported" "T8" "hs"
+  , testCase "Semantic and Lexical errors are reported" $ do
+      evalInFile "T8.hs" "-- >>> noFunctionWithThisName" "-- Variable not in scope: noFunctionWithThisName"
+      evalInFile "T8.hs" "-- >>> \"a\" + \"bc\"" $
+        if ghcVersion == GHC901
+          then "-- No instance for (Num String) arising from a use of ‘+’"
+          else "-- No instance for (Num [Char]) arising from a use of ‘+’"
+      evalInFile "T8.hs" "-- >>> \"" "-- lexical error in string/character literal at end of input"
+      evalInFile "T8.hs" "-- >>> 3 `div` 0" "-- divide by zero"
   , goldenWithEval "Applies file LANGUAGE extensions" "T9" "hs"
   , goldenWithEval "Evaluate a type with :kind!" "T10" "hs"
   , goldenWithEval "Reports an error for an incorrect type with :kind!" "T11" "hs"
@@ -81,9 +83,24 @@ tests =
   , goldenWithEval "Returns defaulted type for :type +d reflecting the default declaration specified in the >>> prompt" "T19" "hs"
   , expectFailBecause "known issue - see a note in P.R. #361" $
       goldenWithEval ":type +d reflects the `default' declaration of the module" "T20" "hs"
-  , goldenWithEval ":type handles a multilined result properly" "T21" "hs"
+  , testCase ":type handles a multilined result properly" $
+      evalInFile "T21.hs" "-- >>> :type fun" $ T.unlines [
+        "-- fun",
+        if ghcVersion == GHC901 
+          then "--   :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}."
+          else "--   :: forall k1 (k2 :: Nat) (n :: Nat) (a :: k1).",
+        "--      (KnownNat k2, KnownNat n, Typeable a) =>",
+        "--      Proxy k2 -> Proxy n -> Proxy a -> ()"
+      ]
   , goldenWithEval ":t behaves exactly the same as :type" "T22" "hs"
-  , goldenWithEval ":type does \"dovetails\" for short identifiers" "T23" "hs"
+  , testCase ":type does \"dovetails\" for short identifiers" $
+      evalInFile "T23.hs" "-- >>> :type f" $ T.unlines [
+        if ghcVersion == GHC901 
+          then "-- f :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}."
+          else "-- f :: forall k1 (k2 :: Nat) (n :: Nat) (a :: k1).",
+        "--      (KnownNat k2, KnownNat n, Typeable a) =>",
+        "--      Proxy k2 -> Proxy n -> Proxy a -> ()"
+      ]
   , goldenWithEval ":kind! treats a multilined result properly" "T24" "hs"
   , goldenWithEval ":kind treats a multilined result properly" "T25" "hs"
   , goldenWithEval "local imports" "T26" "hs"
@@ -97,6 +114,12 @@ tests =
   -- , goldenWithEval "Local Modules can be imported in a test" "TLocalImportInTest" "hs"
   , goldenWithEval "Setting language option TupleSections" "TLanguageOptionsTupleSections" "hs"
   , goldenWithEval ":set accepts ghci flags" "TFlags" "hs"
+  , testCase ":set -fprint-explicit-foralls works" $ do
+      evalInFile "T8.hs" "-- >>> :t id" "-- id :: a -> a"
+      evalInFile "T8.hs" "-- >>> :set -fprint-explicit-foralls\n-- >>> :t id" $
+        if ghcVersion == GHC901
+          then "-- id :: forall {a}. a -> a"
+          else "-- id :: forall a. a -> a"
   , goldenWithEval "The default language extensions for the eval plugin are the same as those for ghci" "TSameDefaultLanguageExtensionsAsGhci" "hs"
   , goldenWithEval "IO expressions are supported, stdout/stderr output is ignored" "TIO" "hs"
   , goldenWithEval "Property checking" "TProperty" "hs"
@@ -202,3 +225,13 @@ codeLensTestOutput codeLens = do
 
 testDataDir :: FilePath
 testDataDir = "test" </> "testdata"
+
+evalInFile :: FilePath -> T.Text -> T.Text -> IO ()
+evalInFile fp e expected = runSessionWithServer evalPlugin testDataDir $ do
+  doc <- openDoc fp "haskell"
+  origin <- documentContents doc
+  let withEval = origin <> e
+  changeDoc doc [TextDocumentContentChangeEvent Nothing Nothing withEval]
+  executeLensesBackwards doc
+  result <- fmap T.strip . T.stripPrefix withEval <$> documentContents doc
+  liftIO $ result @?= Just (T.strip expected)
diff --git a/plugins/hls-eval-plugin/test/testdata/T21.expected.hs b/plugins/hls-eval-plugin/test/testdata/T21.expected.hs
deleted file mode 100644
index 6e23213474..0000000000
--- a/plugins/hls-eval-plugin/test/testdata/T21.expected.hs
+++ /dev/null
@@ -1,16 +0,0 @@
-{-# LANGUAGE PolyKinds           #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-module T21 where
-import Data.Proxy (Proxy(..))
-import GHC.TypeNats (KnownNat)
-import Type.Reflection (Typeable)
-
-fun :: forall k n a. (KnownNat k, KnownNat n, Typeable a)
-    => Proxy k -> Proxy n -> Proxy a -> ()
-fun _ _ _ = ()
-
--- >>> :type fun
--- fun
---   :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}.
---      (KnownNat k2, KnownNat n, Typeable a) =>
---      Proxy k2 -> Proxy n -> Proxy a -> ()
diff --git a/plugins/hls-eval-plugin/test/testdata/T21.hs b/plugins/hls-eval-plugin/test/testdata/T21.hs
index 0570b8d36e..64068f55ed 100644
--- a/plugins/hls-eval-plugin/test/testdata/T21.hs
+++ b/plugins/hls-eval-plugin/test/testdata/T21.hs
@@ -9,4 +9,3 @@ fun :: forall k n a. (KnownNat k, KnownNat n, Typeable a)
     => Proxy k -> Proxy n -> Proxy a -> ()
 fun _ _ _ = ()
 
--- >>> :type fun
diff --git a/plugins/hls-eval-plugin/test/testdata/T23.expected.hs b/plugins/hls-eval-plugin/test/testdata/T23.expected.hs
deleted file mode 100644
index dbe7fa6ff0..0000000000
--- a/plugins/hls-eval-plugin/test/testdata/T23.expected.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-{-# LANGUAGE PolyKinds           #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-module T23 where
-import Data.Proxy      (Proxy (..))
-import GHC.TypeNats    (KnownNat)
-import Type.Reflection (Typeable)
-
-f :: forall k n a. (KnownNat k, KnownNat n, Typeable a)
-  => Proxy k -> Proxy n -> Proxy a -> ()
-f _ _ _ = ()
-
--- >>> :type f
--- f :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}.
---      (KnownNat k2, KnownNat n, Typeable a) =>
---      Proxy k2 -> Proxy n -> Proxy a -> ()
diff --git a/plugins/hls-eval-plugin/test/testdata/T23.hs b/plugins/hls-eval-plugin/test/testdata/T23.hs
index 6f9c73a12e..0a9edaa5c9 100644
--- a/plugins/hls-eval-plugin/test/testdata/T23.hs
+++ b/plugins/hls-eval-plugin/test/testdata/T23.hs
@@ -9,4 +9,3 @@ f :: forall k n a. (KnownNat k, KnownNat n, Typeable a)
   => Proxy k -> Proxy n -> Proxy a -> ()
 f _ _ _ = ()
 
--- >>> :type f
diff --git a/plugins/hls-eval-plugin/test/testdata/T8.expected.hs b/plugins/hls-eval-plugin/test/testdata/T8.expected.hs
deleted file mode 100644
index 94db41d104..0000000000
--- a/plugins/hls-eval-plugin/test/testdata/T8.expected.hs
+++ /dev/null
@@ -1,14 +0,0 @@
--- Semantic and Lexical errors are reported
-module T8 where
-
--- >>> noFunctionWithThisName
--- Variable not in scope: noFunctionWithThisName
-
--- >>> "a" + "bc"
--- No instance for (Num String) arising from a use of ‘+’
-
--- >>> "
--- lexical error in string/character literal at end of input
-
--- >>> 3 `div` 0
--- divide by zero
diff --git a/plugins/hls-eval-plugin/test/testdata/T8.hs b/plugins/hls-eval-plugin/test/testdata/T8.hs
index a0188670b0..44cd164a09 100644
--- a/plugins/hls-eval-plugin/test/testdata/T8.hs
+++ b/plugins/hls-eval-plugin/test/testdata/T8.hs
@@ -1,10 +1,2 @@
--- Semantic and Lexical errors are reported
+-- An empty playground
 module T8 where
-
--- >>> noFunctionWithThisName
-
--- >>> "a" + "bc"
-
--- >>> "
-
--- >>> 3 `div` 0
diff --git a/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs b/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs
index b15a988534..2ee96ac131 100644
--- a/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs
+++ b/plugins/hls-eval-plugin/test/testdata/TFlags.expected.hs
@@ -49,17 +49,6 @@ It still works
 
 -}
 
-{- -fprint-* families
-
->>> :t id
-id :: a -> a
-
-
->>> :set -fprint-explicit-foralls
->>> :t id
-id :: forall {a}. a -> a
-
--}
 
 {- Invalid option/flags are reported, but valid ones will be reflected
 
diff --git a/plugins/hls-eval-plugin/test/testdata/TFlags.hs b/plugins/hls-eval-plugin/test/testdata/TFlags.hs
index c8b49a6e2a..7218f3d7bf 100644
--- a/plugins/hls-eval-plugin/test/testdata/TFlags.hs
+++ b/plugins/hls-eval-plugin/test/testdata/TFlags.hs
@@ -45,15 +45,6 @@ It still works
 
 -}
 
-{- -fprint-* families
-
->>> :t id
-
-
->>> :set -fprint-explicit-foralls
->>> :t id
-
--}
 
 {- Invalid option/flags are reported, but valid ones will be reflected
 

From 3aeccce9a7a292d6063cf2f18f6a939de2d5a4ef Mon Sep 17 00:00:00 2001
From: Potato Hatsue <1793913507@qq.com>
Date: Mon, 5 Jul 2021 14:40:17 +0800
Subject: [PATCH 11/11] Update test

---
 plugins/hls-eval-plugin/test/Main.hs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/plugins/hls-eval-plugin/test/Main.hs b/plugins/hls-eval-plugin/test/Main.hs
index 2933a2ca00..38fbf660a6 100644
--- a/plugins/hls-eval-plugin/test/Main.hs
+++ b/plugins/hls-eval-plugin/test/Main.hs
@@ -86,7 +86,7 @@ tests =
   , testCase ":type handles a multilined result properly" $
       evalInFile "T21.hs" "-- >>> :type fun" $ T.unlines [
         "-- fun",
-        if ghcVersion == GHC901 
+        if ghcVersion == GHC901
           then "--   :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}."
           else "--   :: forall k1 (k2 :: Nat) (n :: Nat) (a :: k1).",
         "--      (KnownNat k2, KnownNat n, Typeable a) =>",
@@ -95,7 +95,7 @@ tests =
   , goldenWithEval ":t behaves exactly the same as :type" "T22" "hs"
   , testCase ":type does \"dovetails\" for short identifiers" $
       evalInFile "T23.hs" "-- >>> :type f" $ T.unlines [
-        if ghcVersion == GHC901 
+        if ghcVersion == GHC901
           then "-- f :: forall {k1} {k2 :: Nat} {n :: Nat} {a :: k1}."
           else "-- f :: forall k1 (k2 :: Nat) (n :: Nat) (a :: k1).",
         "--      (KnownNat k2, KnownNat n, Typeable a) =>",
@@ -116,10 +116,8 @@ tests =
   , goldenWithEval ":set accepts ghci flags" "TFlags" "hs"
   , testCase ":set -fprint-explicit-foralls works" $ do
       evalInFile "T8.hs" "-- >>> :t id" "-- id :: a -> a"
-      evalInFile "T8.hs" "-- >>> :set -fprint-explicit-foralls\n-- >>> :t id" $
-        if ghcVersion == GHC901
-          then "-- id :: forall {a}. a -> a"
-          else "-- id :: forall a. a -> a"
+      evalInFile "T8.hs" "-- >>> :set -fprint-explicit-foralls\n-- >>> :t id"
+        "-- id :: forall {a}. a -> a"
   , goldenWithEval "The default language extensions for the eval plugin are the same as those for ghci" "TSameDefaultLanguageExtensionsAsGhci" "hs"
   , goldenWithEval "IO expressions are supported, stdout/stderr output is ignored" "TIO" "hs"
   , goldenWithEval "Property checking" "TProperty" "hs"