Fix test for code completion of qualified name.

Stop messing around the editing the file and reloading it. We are trying to test
code completion, not editing files, and the extra complexity is making it harder
to maintain the test.

Author: peterwicksstringfield

test/functional/Completion.hs

@@ -366,28 +366,11 @@ contextTests = testGroup "contexts" [
     , testCase "completes qualified type suggestions" $ runSession hlsCommand fullCaps "test/testdata/completion" $ do
         doc <- openDoc "Context.hs" "haskell"
         _ <- waitForDiagnosticsFrom doc
-        let te = TextEdit (Range (Position 2 17) (Position 2 17)) " -> Conc."
-        _ <- applyEdit doc te
-        -- The module doesn't parse right now. So we are using stale data. HLS
-        -- can give us completions for "Conc." but it can't tell that we are in
-        -- a context where we expect a type.
         compls <- getCompletions doc (Position 2 26)
         liftIO $ do
-            -- forkOn is an inappropriate completion in a type context.
-            compls `shouldContainCompl` "forkOn"
+            compls `shouldNotContainCompl` "forkOn"
             compls `shouldContainCompl` "MVar"
             compls `shouldContainCompl` "Chan"
-        let te' = TextEdit (Range (Position 2 26) (Position 2 26)) "MVar"
-        _ <- applyEdit doc te'
-        -- The module can now be parsed. Wait until it has been.
-        _ <- waitForDiagnosticsFrom doc
-        -- HLS can see that we are expecting a type.
-        compls' <- getCompletions doc (Position 2 26)
-        liftIO $ do
-            -- forkOn is gone.
-            compls' `shouldNotContainCompl` "forkOn"
-            compls' `shouldContainCompl` "MVar"
-            compls' `shouldContainCompl` "Chan"
     ]
 
 shouldContainCompl :: [CompletionItem] -> T.Text -> Assertion

test/testdata/completion/Context.hs

@@ -1,4 +1,4 @@
 module Context where
 import Control.Concurrent as Conc
-foo :: Int -> Int
+foo :: Int -> Int -> Conc.MVar
 foo x = abs $ id 42