Add formatting plugin for cabal files which uses cabal-fmt (#2047)

* Add plugin for formatting cabal files using cabal-fmt

* Add 'isolateTests' cabal flag to make plugin install cabal-fmt

For CI, we want to run the tests with a specific cabal-fmt version,
installed automatically by cabal.
However, locally, we might want to test with a locally installed
cabal-fmt version.
This flag allows developers to either let cabal install the
build-tool-depends or install a fitting version locally.

* Ignore failing cabal-fmt test on windows

* Add log message for missing cabal-fmt executable

Co-authored-by: Jana Chadt <[email protected]>
Co-authored-by: Fendor <[email protected]>

Author: 3 people

.github/workflows/test.yml

@@ -254,6 +254,11 @@ jobs:
         name: Test hls-explicit-record-fields-plugin test suite
         run: cabal test hls-explicit-record-fields-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-explicit-record-fields-plugin --test-options="$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 --flag=isolateTests --test-options="$TEST_OPTS" || cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-cabal-fmt-plugin --flag=isolateTests --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

@@ -8,6 +8,7 @@ packages:
          ./ghcide/test
          ./hls-plugin-api
          ./hls-test-utils
+         ./plugins/hls-cabal-fmt-plugin
          ./plugins/hls-tactics-plugin
          ./plugins/hls-brittany-plugin
          ./plugins/hls-stylish-haskell-plugin

docs/features.md

@@ -107,6 +107,13 @@ 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/support/plugin-support.md

@@ -46,6 +46,7 @@ For example, a plugin to provide a formatter which has itself been abandoned has
 | `hls-pragmas-plugin`                | 1    |                          |
 | `hls-refactor-plugin`               | 1    | 9.4                      |
 | `hls-alternate-number-plugin`       | 2    |                          |
+| `hls-cabal-fmt-plugin`              | 2    |                          |
 | `hls-class-plugin`                  | 2    |                          |
 | `hls-change-type-signature-plugin`  | 2    |                          |
 | `hls-eval-plugin`                   | 2    | 9.4                      |

haskell-language-server.cabal

@@ -205,6 +205,16 @@ flag dynamic
   default:     True
   manual:      True
 
+flag cabalfmt
+  description: Enable cabal-fmt plugin
+  default:     True
+  manual:      True
+
+common cabalfmt
+  if flag(cabalfmt)
+    build-depends: hls-cabal-fmt-plugin ^>= 0.1.0.0
+    cpp-options: -Dhls_cabalfmt
+
 common class
   if flag(class)
     build-depends: hls-class-plugin ^>= 1.1

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

@@ -47,11 +47,12 @@ data CheckParents
 -- will be surprises relating to config options being ignored, initially though.
 data Config =
   Config
-    { checkParents       :: CheckParents
-    , checkProject       :: !Bool
-    , formattingProvider :: !T.Text
-    , maxCompletions     :: !Int
-    , plugins            :: !(Map.Map T.Text PluginConfig)
+    { checkParents            :: CheckParents
+    , checkProject            :: !Bool
+    , formattingProvider      :: !T.Text
+    , cabalFormattingProvider :: !T.Text
+    , maxCompletions          :: !Int
+    , plugins                 :: !(Map.Map T.Text PluginConfig)
     } deriving (Show,Eq)
 
 instance Default Config where
@@ -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

@@ -403,14 +403,15 @@ 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,
@@ -70,6 +72,7 @@ import           Development.IDE.Types.Options
 import           GHC.IO.Handle
 import           GHC.Stack                       (emptyCallStack)
 import           Ide.Plugin.Config               (Config, PluginConfig,
+                                                  cabalFormattingProvider,
                                                   formattingProvider, plugins)
 import           Ide.PluginUtils                 (idePluginsToPluginDesc,
                                                   pluginDescToIdePlugins)
@@ -130,15 +133,30 @@ 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 +169,33 @@ 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