Add example plugin

exe/Plugins.hs

@@ -13,6 +13,7 @@ import           Development.IDE                   (IdeState)
 import qualified Development.IDE.Plugin.HLS.GhcIde as GhcIde
 import qualified Ide.Plugin.Example                as Example
 import qualified Ide.Plugin.Example2               as Example2
+import qualified Ide.Plugin.ExampleCabal               as ExampleCabal
 
 -- haskell-language-server optional plugins
 #if qualifyImportedNames
@@ -204,4 +205,5 @@ idePlugins recorder includeExamples = pluginDescToIdePlugins allPlugins
     examplePlugins =
       [Example.descriptor  pluginRecorder "eg"
       ,Example2.descriptor pluginRecorder "eg2"
+      ,ExampleCabal.descriptor pluginRecorder "ec"
       ]

plugins/default/src/Ide/Plugin/ExampleCabal.hs

@@ -1,2 +1,53 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE OverloadedStrings #-}
 module Ide.Plugin.ExampleCabal where
 
+import           Data.Aeson
+import qualified Data.HashMap.Strict        as Map
+import qualified Data.Text                  as T
+import           Development.IDE            as D
+import qualified Development.IDE.Core.Shake as Shake
+import           GHC.Generics
+import           Ide.Types
+import           Language.LSP.Server
+import           Language.LSP.Types
+import           Text.Regex.TDFA.Text       ()
+
+
+newtype Log = LogShake Shake.Log deriving Show
+
+instance Pretty Log where
+  pretty = \case
+    LogShake log -> pretty log
+
+descriptor :: Recorder (WithPriority Log) -> PluginId -> PluginDescriptor IdeState
+descriptor _recorder plId = (defaultCabalPluginDescriptor plId)
+  { pluginCommands = [PluginCommand "codelens.todo" "example adding" addTodoCmd]
+  }
+
+-- ---------------------------------------------------------------------
+-- | Parameters for the addTodo PluginCommand.
+data AddTodoParams = AddTodoParams
+  { file     :: Uri  -- ^ Uri of the file to add the pragma to
+  , todoText :: T.Text
+  }
+  deriving (Show, Eq, Generic, ToJSON, FromJSON)
+
+addTodoCmd :: CommandFunction IdeState AddTodoParams
+addTodoCmd _ide (AddTodoParams uri todoText) = do
+  let
+    pos = Position 3 0
+    textEdits = List
+      [TextEdit (Range pos pos)
+                  ("-- TODO:" <> todoText <> "\n")
+      ]
+    res = WorkspaceEdit
+      (Just $ Map.singleton uri textEdits)
+      Nothing
+      Nothing
+  _ <- sendRequest SWorkspaceApplyEdit (ApplyWorkspaceEditParams Nothing res) (\_ -> pure ())
+  return $ Right Null
+
+-- ---------------------------------------------------------------------