Add default-extension completions in .cabal files

Suggest all known language extensions for the `default-extensions` field
in .cabal files.

Also add a new variation, `mkParameterisedTestCaseM`, of `mkParameterisedTestCase` which takes
an Assertion instead checking for equality of the given values.

Author: VeryMilkyJoe

hls-test-utils/src/Test/Hls.hs

@@ -36,6 +36,7 @@ module Test.Hls
     runSessionWithTestConfig,
     -- * Running parameterised tests for a set of test configurations
     parameterisedCursorTest,
+    parameterisedCursorTestM,
     -- * Helpful re-exports
     PluginDescriptor,
     IdeState,
@@ -383,8 +384,15 @@ goldenWithDocInTmpDir languageKind config plugin title tree path desc ext act =
 -- The quasi quoter '__i' is very helpful to define such tests, as it additionally
 -- allows to interpolate haskell values and functions. We reexport this quasi quoter
 -- for easier usage.
-parameterisedCursorTest :: (Show a, Eq a) => String -> T.Text -> [a] -> (T.Text -> PosPrefixInfo -> IO a) -> TestTree
-parameterisedCursorTest title content expectations act
+parameterisedCursorTest :: forall a . (Show a, Eq a) => String -> T.Text -> [a] -> (T.Text -> PosPrefixInfo -> IO a) -> TestTree
+parameterisedCursorTest title content expectations act = parameterisedCursorTestM title content assertions act
+  where
+    assertions = map testCaseAssertion expectations
+    testCaseAssertion :: a -> PosPrefixInfo -> a -> Assertion
+    testCaseAssertion expected info actual = assertEqual (mkParameterisedLabel info) actual expected
+
+parameterisedCursorTestM :: String -> T.Text -> [(PosPrefixInfo -> a -> Assertion)] -> (T.Text -> PosPrefixInfo -> IO a) -> TestTree
+parameterisedCursorTestM title content expectations act
   | lenPrefs /= lenExpected = error $ "parameterisedCursorTest: Expected " <> show lenExpected <> " cursors but found: " <> show lenPrefs
   | otherwise = testGroup title $
       map singleTest testCaseSpec
@@ -395,9 +403,9 @@ parameterisedCursorTest title content expectations act
 
     testCaseSpec = zip [1 ::Int ..] (zip expectations prefInfos)
 
-    singleTest (n, (expected, info)) = testCase (title <> " " <> show n) $ do
+    singleTest (n, (assert, info)) = testCase (title <> " " <> show n) $ do
       actual <- act cleanText info
-      assertEqual (mkParameterisedLabel info) expected actual
+      assert info actual
 
 -- ------------------------------------------------------------
 -- Helper function for initialising plugins under test

plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal/Completion/Data.hs

@@ -15,7 +15,8 @@ import           Ide.Plugin.Cabal.Completion.Completer.Simple
 import           Ide.Plugin.Cabal.Completion.Completer.Types    (Completer)
 import           Ide.Plugin.Cabal.Completion.Types
 import           Ide.Plugin.Cabal.LicenseSuggest                (licenseNames)
-
+import           Language.Haskell.Extension
+import Distribution.Pretty (prettyShow)
 -- | Ad-hoc data type for modelling the available top-level stanzas.
 -- Not intended right now for anything else but to avoid string
 -- comparisons in 'stanzaKeywordMap' and 'libExecTestBenchCommons'.
@@ -177,8 +178,8 @@ libExecTestBenchCommons st =
     [ ("import:", importCompleter),
       ("build-depends:", noopCompleter),
       ("hs-source-dirs:", directoryCompleter),
-      ("default-extensions:", noopCompleter),
-      ("other-extensions:", noopCompleter),
+      ("default-extensions:", constantCompleter $ map (T.pack . prettyShow) allExtensions),
+      ("other-extensions:", constantCompleter $ map (T.pack . prettyShow) allExtensions),
       ("default-language:", constantCompleter ["GHC2021", "Haskell2010", "Haskell98"]),
       ("other-languages:", noopCompleter),
       ("build-tool-depends:", noopCompleter),
@@ -235,6 +236,19 @@ libExecTestBenchCommons st =
         -- but not have erased the "common" stanza.
         noopCompleter
 
+-- | Returns all possible language extensions including disabled ones.
+allExtensions :: [Extension]
+allExtensions =
+  concatMap
+    ( \e ->
+        -- These pragmas cannot be negated as they are not reversible
+        -- by prepending "No".
+        if e `notElem` [Unsafe, Trustworthy, Safe]
+          then [EnableExtension e, DisableExtension e]
+          else [EnableExtension e]
+    )
+    knownExtensions
+
 -- | Contains a map of the most commonly used licenses, weighted by their popularity.
 --
 --  The data was extracted by Kleidukos from the alternative hackage frontend flora.pm.

plugins/hls-cabal-plugin/test/Completer.hs

@@ -31,6 +31,8 @@ import           System.FilePath
 import           Test.Hls
 import qualified Text.Fuzzy.Parallel                            as Fuzzy
 import           Utils
+import Test.Hls.FileSystem (text, file, mkVirtualFileTree)
+import Development.IDE.Plugin.Completions.Types (cursorPos)
 
 completerTests :: TestTree
 completerTests =
@@ -73,7 +75,20 @@ basicCompleterTests =
         let complTexts = getTextEditTexts compls
         liftIO $ assertBool "suggests f2" $ "f2.hs" `elem` complTexts
         liftIO $ assertBool "does not suggest" $ "Content.hs" `notElem` complTexts
-    ]
+    , parameterisedCursorTestM "extensions completion" libraryStanzaData
+        [ \_ actual -> assertBool "suggests FieldSelectors" $ "FieldSelectors" `elem` actual
+        , \_ actual -> assertBool "suggests OverloadedStrings" $ "OverloadedStrings" `elem` actual
+        , \_ actual -> assertBool "suggests something" $ not . null $ actual
+        , \_ actual -> assertBool "suggests NoLambdaCase" $ "NoLambdaCase" `elem` actual
+        , \_ actual -> assertBool "suggests RecordWildCards" $ "RecordWildCards" `elem` actual
+        ]
+        $ \fileContent posPrefInfo -> do
+            let vFileTree = mkVirtualFileTree "" $ [file "cabalFile.cabal" $ text fileContent]
+            runCabalSessionVft vFileTree $ do
+              doc <- openDoc "cabalFile.cabal" "cabal"
+              compls <- getCompletions doc (cursorPos posPrefInfo)
+              let complTexts = getTextEditTexts compls
+              pure complTexts]
     where
       getTextEditTexts :: [CompletionItem] -> [T.Text]
       getTextEditTexts compls = mapMaybe (^? L.textEdit . _Just . _L . L.newText) compls
@@ -401,40 +416,27 @@ extract item = case item ^. L.textEdit of
   Just (InL v) -> v ^. L.newText
   _            -> error ""
 
-importTestData :: T.Text
-importTestData = [__i|
-  cabal-version:      3.0
-  name:               hls-cabal-plugin
-  version:            0.1.0.0
-  synopsis:
-  homepage:
-  license:            MIT
-  license-file:       LICENSE
-  author:             Fendor
-  maintainer:         fendor@posteo.de
-  category:           Development
-  extra-source-files: CHANGELOG.md
-
-  common defaults
-    default-language: GHC2021
-    -- Should have been in GHC2021, an oversight
-    default-extensions: ExplicitNamespaces
-
-  common test-defaults
-    ghc-options: -threaded -rtsopts -with-rtsopts=-N
-
-  library
-      import:
-              ^
-      exposed-modules:  IDE.Plugin.Cabal
-      build-depends:    base ^>=4.14.3.0
-      hs-source-dirs:   src
-      default-language: Haskell2010
-
-  common notForLib
-    default-language: GHC2021
+-- ------------------------------------------------------------------------
+-- Test Data
+-- ------------------------------------------------------------------------
 
-  test-suite tests
-    import:
-            ^
+libraryStanzaData :: T.Text
+libraryStanzaData = [__i|
+    cabal-version:      3.0
+    name:               simple-cabal
+    common mylib
+      default-extensions: Field
+                               ^
+    library
+        default-extensions: Ov
+                              ^
+    test-suite mysuite
+        default-extensions:
+                            ^
+    executable myexe
+        default-extensions: NoLam
+                                 ^
+    benchmark mybench
+        other-extensions: RecordW
+                                 ^
 |]