Add plugin for formatting cabal files using cabal-fmt

Author: Jana Chadt

.github/workflows/test.yml

@@ -244,9 +244,14 @@ jobs:
         run: cabal test hls-change-type-signature-plugin --test-options="$TEST_OPTS" || cabal test hls-change-type-signature-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-change-type-signature-plugin --test-options="$TEST_OPTS"
 
       - if: matrix.test
-        name: Test hls-gadt-plugin test suit
+        name: Test hls-gadt-plugin test suite
         run: cabal test hls-gadt-plugin --test-options="$TEST_OPTS" || cabal test hls-gadt-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-gadt-plugin --test-options="$TEST_OPTS"
 
+      ## version needs to be limited since the tests depend on cabal-fmt which only builds using specific ghc versions
+      - if: matrix.test && matrix.ghc == '8.10.7'
+        name: Test hls-cabal-fmt-plugin test suite
+        run: cabal test hls-cabal-fmt-plugin --test-options="$TEST_OPTS" || cabal test hls-cabal-fmt-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-cabal-fmt-plugin --test-options="$TEST_OPTS"
+
   test_post_job:
     if: always()
     runs-on: ubuntu-latest

CODEOWNERS

@@ -9,6 +9,7 @@
 # Plugins
 /plugins/hls-alternate-number-format-plugin @drsooch
 /plugins/hls-brittany-plugin @fendor
+/plugins/hls-cabal-fmt-plugin @VeryMilkyJoe @fendor
 /plugins/hls-call-hierarchy-plugin @July541
 /plugins/hls-class-plugin @Ailrun
 /plugins/hls-eval-plugin

cabal.project

@@ -6,6 +6,7 @@ packages:
          ./ghcide
          ./hls-plugin-api
          ./hls-test-utils
+         ./plugins/hls-cabal-fmt-plugin
          ./plugins/hls-tactics-plugin
          ./plugins/hls-brittany-plugin
          ./plugins/hls-stylish-haskell-plugin
@@ -67,5 +68,8 @@ allow-newer:
   -- ghc-9.2
   ----------
   hiedb:base,
+  -- needed for tests of hls-cabal-fmt-plugin
+  cabal-fmt:base,
+  cabal-fmt:bytestring,
 
   ekg-wai:time

docs/features.md

@@ -95,6 +95,13 @@ Format your code with various Haskell code formatters.
 | Ormolu          | `hls-ormolu-plugin`          |
 | Stylish Haskell | `hls-stylish-haskell-plugin` |
 
+Format your cabal files with a cabal code formatter.
+
+| Formatter       | Provided by                  |
+|-----------------|------------------------------|
+| cabal-fmt       | `hls-cabal-fmt-plugin`       |
+
+
 ## Document symbols
 
 Provided by: `ghcide`

docs/supported-versions.md

@@ -37,7 +37,8 @@ Sometimes a plugin will be supported in the prebuilt binaries but not in a HLS b
 | Plugin                              | Unsupported GHC versions |
 |-------------------------------------|--------------------------|
 | `hls-alternate-number-plugin`       |                          |
-| `hls-brittany-plugin`               | 9.2      |
+| `hls-brittany-plugin`               | 9.2                      |
+| `hls-cabal-fmt-plugin`              |                          |
 | `hls-call-hierarchy-plugin`         |                          |
 | `hls-class-plugin`                  |                          |
 | `hls-eval-plugin`                   |                          |

exe/Plugins.hs

@@ -109,6 +109,10 @@ import qualified Ide.Plugin.StylishHaskell         as StylishHaskell
 import qualified Ide.Plugin.Brittany               as Brittany
 #endif
 
+#if cabalfmt
+import qualified Ide.Plugin.CabalFmt               as CabalFmt
+#endif
+
 data Log = forall a. (Pretty a) => Log a
 
 instance Pretty Log where
@@ -157,6 +161,9 @@ idePlugins recorder includeExamples = pluginDescToIdePlugins allPlugins
 #if brittany
       Brittany.descriptor "brittany" :
 #endif
+#if cabalfmt
+      CabalFmt.descriptor pluginRecorder "cabal-fmt" :
+#endif
 #if callHierarchy
       CallHierarchy.descriptor :
 #endif

haskell-language-server.cabal

@@ -229,6 +229,11 @@ common example-plugins
                  Ide.Plugin.Example2,
                  Ide.Plugin.ExampleCabal
 
+flag cabalfmt
+  description: Enable cabal-fmt plugin
+  default:     True
+  manual:      True
+
 common class
   if flag(class)
     build-depends: hls-class-plugin ^>= 1.0
@@ -346,6 +351,11 @@ common brittany
     build-depends: hls-brittany-plugin ^>= 1.0
     cpp-options: -Dbrittany
 
+common cabalfmt
+  if flag(cabalfmt)
+    build-depends: hls-cabal-fmt-plugin ^>= 0.1.0.0
+    cpp-options: -Dcabalfmt
+
 executable haskell-language-server
   import:             common-deps
                     -- configuration
@@ -376,6 +386,7 @@ executable haskell-language-server
                     , ormolu
                     , stylishHaskell
                     , brittany
+                    , cabalfmt
 
   main-is:          Main.hs
   hs-source-dirs:   exe

hls-plugin-api/src/Ide/Plugin/Config.hs

@@ -50,6 +50,7 @@ data Config =
     { checkParents       :: CheckParents
     , checkProject       :: !Bool
     , formattingProvider :: !T.Text
+    , cabalFormattingProvider :: !T.Text
     , maxCompletions     :: !Int
     , plugins            :: !(Map.Map T.Text PluginConfig)
     } deriving (Show,Eq)
@@ -62,6 +63,7 @@ instance Default Config where
     , formattingProvider          = "ormolu"
     -- , formattingProvider          = "floskell"
     -- , formattingProvider          = "stylish-haskell"
+    , cabalFormattingProvider     = "cabal-fmt"
     , maxCompletions              = 40
     , plugins                     = Map.empty
     }
@@ -78,6 +80,7 @@ parseConfig defValue = A.withObject "Config" $ \v -> do
         <$> (o .:? "checkParents" <|> v .:? "checkParents") .!= checkParents defValue
         <*> (o .:? "checkProject" <|> v .:? "checkProject") .!= checkProject defValue
         <*> o .:? "formattingProvider"                      .!= formattingProvider defValue
+        <*> o .:? "cabalFormattingProvider"                 .!= cabalFormattingProvider defValue
         <*> o .:? "maxCompletions"                          .!= maxCompletions defValue
         <*> o .:? "plugin"                                  .!= plugins defValue
 

hls-plugin-api/src/Ide/Types.hs

@@ -344,14 +344,15 @@ instance PluginMethod Request TextDocumentCompletion where
 
 instance PluginMethod Request TextDocumentFormatting where
   pluginEnabled STextDocumentFormatting msgParams pluginDesc conf =
-    pluginResponsible uri pluginDesc && PluginId (formattingProvider conf) == pid
+    pluginResponsible uri pluginDesc
+      && (PluginId (formattingProvider conf) == pid || PluginId (cabalFormattingProvider conf) == pid)
     where
       uri = msgParams ^. J.textDocument . J.uri
       pid = pluginId pluginDesc
 
 instance PluginMethod Request TextDocumentRangeFormatting where
   pluginEnabled _ msgParams pluginDesc conf = pluginResponsible uri pluginDesc
-      && PluginId (formattingProvider conf) == pid
+      && (PluginId (formattingProvider conf) == pid || PluginId (cabalFormattingProvider conf) == pid)
     where
       uri = msgParams ^. J.textDocument . J.uri
       pid = pluginId pluginDesc

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

@@ -17,9 +17,11 @@ module Test.Hls
     goldenGitDiff,
     goldenWithHaskellDoc,
     goldenWithHaskellDocFormatter,
+    goldenWithCabalDocFormatter,
     def,
     runSessionWithServer,
     runSessionWithServerFormatter,
+    runSessionWithCabalServerFormatter,
     runSessionWithServer',
     waitForProgressDone,
     waitForAllProgressDone,
@@ -70,7 +72,7 @@ import           Development.IDE.Types.Options
 import           GHC.IO.Handle
 import           GHC.Stack                       (emptyCallStack)
 import           Ide.Plugin.Config               (Config, PluginConfig,
-                                                  formattingProvider, plugins)
+                                                  cabalFormattingProvider ,formattingProvider, plugins)
 import           Ide.PluginUtils                 (idePluginsToPluginDesc,
                                                   pluginDescToIdePlugins)
 import           Ide.Types
@@ -130,15 +132,30 @@ goldenWithHaskellDoc plugin title testDataDir path desc ext act =
     act doc
     documentContents doc
 
+
+runSessionWithServer :: PluginDescriptor IdeState -> FilePath -> Session a -> IO a
+runSessionWithServer plugin = runSessionWithServer' [plugin] def def fullCaps
+
+runSessionWithServerFormatter :: PluginDescriptor IdeState -> String -> PluginConfig -> FilePath -> Session a -> IO a
+runSessionWithServerFormatter plugin formatter conf =
+  runSessionWithServer'
+    [plugin]
+    def
+      { formattingProvider = T.pack formatter
+      , plugins = M.singleton (T.pack formatter) conf
+      }
+    def
+    fullCaps
+
 goldenWithHaskellDocFormatter
-  :: PluginDescriptor IdeState
-  -> String
+  :: PluginDescriptor IdeState -- ^ Formatter plugin to be used
+  -> String -- ^ Name of the formatter to be used
   -> PluginConfig
-  -> TestName
-  -> FilePath
-  -> FilePath
-  -> FilePath
-  -> FilePath
+  -> TestName -- ^ Title of the test
+  -> FilePath -- ^ Directory of the test data to be used
+  -> FilePath -- ^ Path to the testdata to be used within the directory
+  -> FilePath -- ^ Additional suffix to be appended to the output file
+  -> FilePath -- ^ Extension of the output file
   -> (TextDocumentIdentifier -> Session ())
   -> TestTree
 goldenWithHaskellDocFormatter plugin formatter conf title testDataDir path desc ext act =
@@ -151,15 +168,33 @@ goldenWithHaskellDocFormatter plugin formatter conf title testDataDir path desc
     act doc
     documentContents doc
 
-runSessionWithServer :: PluginDescriptor IdeState -> FilePath -> Session a -> IO a
-runSessionWithServer plugin = runSessionWithServer' [plugin] def def fullCaps
+goldenWithCabalDocFormatter
+  :: PluginDescriptor IdeState -- ^ Formatter plugin to be used
+  -> String -- ^ Name of the formatter to be used
+  -> PluginConfig
+  -> TestName -- ^ Title of the test
+  -> FilePath -- ^ Directory of the test data to be used
+  -> FilePath -- ^ Path to the testdata to be used within the directory
+  -> FilePath -- ^ Additional suffix to be appended to the output file
+  -> FilePath -- ^ Extension of the output file
+  -> (TextDocumentIdentifier -> Session ())
+  -> TestTree
+goldenWithCabalDocFormatter plugin formatter conf title testDataDir path desc ext act =
+  goldenGitDiff title (testDataDir </> path <.> desc <.> ext)
+  $ runSessionWithCabalServerFormatter plugin formatter conf testDataDir
+  $ TL.encodeUtf8 . TL.fromStrict
+  <$> do
+    doc <- openDoc (path <.> ext) "cabal"
+    void waitForBuildQueue
+    act doc
+    documentContents doc
 
-runSessionWithServerFormatter :: PluginDescriptor IdeState -> String -> PluginConfig -> FilePath -> Session a -> IO a
-runSessionWithServerFormatter plugin formatter conf =
+runSessionWithCabalServerFormatter :: PluginDescriptor IdeState -> String -> PluginConfig -> FilePath -> Session a -> IO a
+runSessionWithCabalServerFormatter plugin formatter conf =
   runSessionWithServer'
     [plugin]
     def
-      { formattingProvider = T.pack formatter
+      { cabalFormattingProvider = T.pack formatter
       , plugins = M.singleton (T.pack formatter) conf
       }
     def