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
@@ -66,5 +67,8 @@ 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

@@ -10,7 +10,7 @@ Last supporting HLS version:
 - specific version number: this GHC version is no longer one of the actively supported versions, and the last version of HLS which supports it is listed.
 
 Support status (see the support policy below for more details):
-- "supported": this version of GHC is currently actively supported 
+- "supported": this version of GHC is currently actively supported
 - "deprecated": this version of GHC was supported in the past, but is now deprecated
 - "will be deprecated ...": this version of GHC has special deprecation conditions that deviate from the support policy
 - "partial": not all features and plugins work, see the plugin support table and any linked issues for more details
@@ -50,6 +50,7 @@ Sometimes a plugin will be supported in the pre-built binaries but not in a HLS
 |-------------------------------------|--------------------------|
 | `hls-alternate-number-plugin`       |                          |
 | `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