Add tests for cabal file completion

plugins/hls-cabal-plugin/test/Main.hs

@@ -3,6 +3,7 @@
 {-# LANGUAGE DisambiguateRecordFields #-}
 {-# LANGUAGE NamedFieldPuns           #-}
 {-# LANGUAGE TypeOperators            #-}
+{-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
 module Main
   ( main
   ) where
@@ -13,6 +14,7 @@ import qualified Data.ByteString                 as BS
 import           Data.Either                     (isRight)
 import qualified Data.Text                       as Text
 import           Ide.Plugin.Cabal
+import           Ide.Plugin.Cabal.Completions
 import           Ide.Plugin.Cabal.LicenseSuggest (licenseErrorSuggestion)
 import qualified Ide.Plugin.Cabal.Parse          as Lib
 import qualified Language.LSP.Types.Lens         as J
@@ -38,7 +40,8 @@ unitTests :: TestTree
 unitTests =
   testGroup "Unit Tests"
   [ cabalParserUnitTests,
-    codeActionUnitTests
+    codeActionUnitTests,
+    completionUnitTests
   ]
 
 cabalParserUnitTests :: TestTree
@@ -66,6 +69,41 @@ codeActionUnitTests = testGroup "Code Action Tests"
         @?= [("MiT","MIT"),("MiT","MIT-0")]
   ]
 
+completionUnitTests :: TestTree
+completionUnitTests = testGroup "Context Tests"
+  [
+    testCase "Empty File - Start" $ do
+      -- for a completely empty file, the context needs to
+      -- be toplevel without a specified keyword
+      getContext (Position 0 0) [""] @?= Just (TopLevel, None),
+    testCase "Cabal version keyword - no value" $ do
+      -- on a file, where the "cabal-version:" keyword is already written
+      -- the context should still be toplevel but the keyword should be recognized
+      getContext  (Position 0 15) ["cabal-version:"] @?= Just (TopLevel, KeyWord "cabal-version:"),
+    testCase "Cabal version keyword - cursor in keyword" $ do
+      -- on a file, where the "cabal-version:" keyword is already written
+      -- but the cursor is in the middle of the keyword, the keyword context
+      -- is cabal-version since after the keyword, the value needs to be inserted still
+      getContext  (Position 0 5) ["cabal-version:"] @?= Just (TopLevel, KeyWord "cabal-version:"),
+    testCase "Cabal version keyword - no value, many spaces" $ do
+      -- on a file, where the "cabal-version:" keyword is already written
+      -- the context should still be toplevel but the keyword should be recognized
+      getContext  (Position 0 45) ["cabal-version:" <> Text.replicate 50 " "] @?= Just (TopLevel, KeyWord "cabal-version:"),
+    testCase "Cabal version keyword - no value, many spaces" $ do
+      -- in the first line of the file, if the keyword
+      -- has not been written completely, the keyword context
+      -- should still be None
+      getContext  (Position 0 5) ["cabal"] @?= Just (TopLevel, None),
+    testCase "Inside Stanza - no keyword" $ do
+      -- on a file, where the library stanza has been defined
+      -- but no keyword is defined afterwards, the stanza context should be recognized
+      getContext  (Position 3 0) libraryStanza @?= Just (Stanza "library", None),
+    testCase "Inside Stanza - keyword, no value" $ do
+      -- on a file, where the library stanza and a keyword
+      -- has been defined, the keyword and stanza should be recognized
+      getContext  (Position 4 21) libraryStanza @?= Just (Stanza "library", KeyWord "build-depends:")
+  ]
+
 -- ------------------------------------------------------------------------
 -- Integration Tests
 -- ------------------------------------------------------------------------
@@ -180,3 +218,16 @@ runCabalSession subdir =
 
 testDataDir :: FilePath
 testDataDir = "test" </> "testdata"
+
+-- ------------------------------------------------------------------------
+-- Test Data
+-- ------------------------------------------------------------------------
+libraryStanza :: [Text.Text]
+libraryStanza =
+  [
+    "cabal-version:      3.0",
+    "name:               simple-cabal",
+    "library ",
+    "",
+    "    build-depends:    "
+  ]