Remove GHCi specific hints from GHC error messages

hspec · Jan 25, 2025 · 6a0d7b2 · 6a0d7b2
1 parent 8dc88eb
commit 6a0d7b2
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Showing 3 changed files with 11 additions and 3 deletions.
diff --git a/src/GHC/Diagnostic.hs b/src/GHC/Diagnostic.hs
@@ -40,7 +40,7 @@ data Severity = Warning | Error
   deriving (Eq, Show, Generic, ToJSON, FromJSON)
 
 parse :: ByteString -> Maybe Diagnostic
-parse = decode . fromStrict
+parse = fmap removeGhciSpecificHints . decode . fromStrict
 
 format :: Diagnostic -> ByteString
 format diagnostic = encodeUtf8 . render $ unlines [
@@ -90,3 +90,11 @@ format diagnostic = encodeUtf8 . render $ unlines [
 
     unlines :: [Doc] -> Doc
     unlines = foldr ($+$) empty
+
+removeGhciSpecificHints :: Diagnostic -> Diagnostic
+removeGhciSpecificHints diagnostic = diagnostic { hints = map f diagnostic.hints }
+  where
+    f :: String -> String
+    f input = case lines input of
+      [hint, "You may enable this language extension in GHCi with:", ghciHint] | "  :set -X" `isPrefixOf` ghciHint -> hint
+      _ -> input
diff --git a/test/GHC/DiagnosticSpec.hs b/test/GHC/DiagnosticSpec.hs
@@ -13,7 +13,7 @@ import           GHC.Diagnostic
 test :: HasCallStack => FilePath -> Spec
 test name = it name $ do
   err <- translate <$> ghc ["-fno-diagnostics-show-caret"]
-  json <- encodeUtf8 <$> ghc ["-fdiagnostics-as-json"]
+  json <- encodeUtf8 <$> ghc ["-fdiagnostics-as-json", "--interactive", "-ignore-dot-ghci"]
   ensureFile (dir </> "err.out") (encodeUtf8 err)
   ensureFile (dir </> "err.json") json
   Just diagnostic <- return $ parse json

diff --git a/test/assets/use-BlockArguments/err.json b/test/assets/use-BlockArguments/err.json
@@ -1 +1 @@
-{"version":"1.0","ghcVersion":"ghc-9.10.1","span":{"file":"test/assets/use-BlockArguments/Foo.hs","start":{"line":5,"column":10},"end":{"line":5,"column":22}},"severity":"Error","code":52095,"message":["Unexpected do block in function application:\n    do return ()"],"hints":["Use parentheses.","Perhaps you intended to use BlockArguments"]}
+{"version":"1.0","ghcVersion":"ghc-9.10.1","span":{"file":"test/assets/use-BlockArguments/Foo.hs","start":{"line":5,"column":10},"end":{"line":5,"column":22}},"severity":"Error","code":52095,"message":["Unexpected do block in function application:\n    do return ()"],"hints":["Use parentheses.","Perhaps you intended to use BlockArguments\nYou may enable this language extension in GHCi with:\n  :set -XBlockArguments"]}
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		{"version":"1.0","ghcVersion":"ghc-9.10.1","span":{"file":"test/assets/use-BlockArguments/Foo.hs","start":{"line":5,"column":10},"end":{"line":5,"column":22}},"severity":"Error","code":52095,"message":["Unexpected do block in function application:\n do return ()"],"hints":["Use parentheses.","Perhaps you intended to use BlockArguments"]}
		{"version":"1.0","ghcVersion":"ghc-9.10.1","span":{"file":"test/assets/use-BlockArguments/Foo.hs","start":{"line":5,"column":10},"end":{"line":5,"column":22}},"severity":"Error","code":52095,"message":["Unexpected do block in function application:\n do return ()"],"hints":["Use parentheses.","Perhaps you intended to use BlockArguments\nYou may enable this language extension in GHCi with:\n :set -XBlockArguments"]}