Implement completion of licenses in cabal files

Currently not sorted in suggestions

Author: VeryMilkyJoe

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

@@ -24,6 +24,7 @@ import           System.Directory              (doesDirectoryExist,
                                                 doesFileExist, listDirectory)
 import           System.FilePath
 import qualified Text.Fuzzy.Parallel           as Fuzzy
+import Ide.Plugin.Cabal.LicenseSuggest (licenseNames)
 
 -- | Takes information needed to build possible completion items
 -- and returns the list of possible completion items
@@ -374,7 +375,7 @@ cabalKeywords =
     [ ("name:", noopCompleter) -- TODO: should complete to filename, needs meta info
     , ("version:", noopCompleter)
     , ("build-type:", constantCompleter ["Simple", "Custom", "Configure", "Make"])
-    , ("license:", constantCompleter ["NONE"]) -- TODO: add possible values, spdx
+    , ("license:", constantCompleter licenseNames)
     , ("license-file:", filePathCompleter)
     , ("license-files:", filePathCompleter) -- list of filenames
     , ("copyright:", noopCompleter)

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

@@ -6,6 +6,7 @@
 module Ide.Plugin.Cabal.LicenseSuggest
 ( licenseErrorSuggestion
 , licenseErrorAction
+, licenseNames
   -- * Re-exports
 , T.Text
 , Diagnostic(..)