Add goto def / hover tests for classes (#177)

+ internal class in instance declaration
+ internal class in type signature
+ external class in type signature

Hover seems not to work for classes at all.

Goto def works for internal classes, but not external ones.

This leaves the table looking like this:

| | find definition | hover |
|-------------|-----------|---------|
| field in record definition | ✔️  | ✔️ |
| field in record construction | ❌  | ❌ |
| field name as accessor | ✔️ | ✔️ |
| top level name | ✔️ | ✔️ |
| record data constructor | ❌ | ❌ |
| plain data constructor | ✔️ | ✔️  |
| type constructor | ✔️ | ❌ |
| external type constructor | ❌ | ❌ |
| external value | ❌ | ✔️ |
| plain parameter | ✔️ | ✔️ |
| pattern match name | ✔️ | ✔️ |
| top level operator | ✔️ | ✔️ |
| parameter operator | ✔️  | ✔️  |
| name in backticks | ✔️ | ✔️ |
| class in instance declaration | ✔️ | ❌ |
| class in signature | ✔️ | ❌ |
| external class in signature | ❌ | ❌ |

Author: jacg

test/data/GotoHover.hs

@@ -19,3 +19,9 @@ a +! b = a - b
 hhh (Just a) (><) = a >< a
 iii a b = a `b` a
 jjj s = pack $ s <> s
+class Class a where
+  method :: a -> Int
+instance Class Int where
+  method = succ
+kkk :: Class a => Int -> a -> Int
+kkk n c = n + method c

test/exe/Main.hs

@@ -781,7 +781,9 @@ findDefinitionAndHoverTests = let
   aL18   = Position 18 20  ;  apmp   = [mkR  18 10   18 11]
   b'L19  = Position 19 13  ;  bp     = [mkR  19  6   19  7]
   xvL20  = Position 20  8  ;  xvMsg  = [ExpectHoverText ["Data.Text.pack", ":: String -> Text"], ExpectExternFail]
-
+  clL23  = Position 23 11  ;  cls    = [mkR  21  0   22 20]
+  clL25  = Position 25  9
+  eclL15 = Position 15  8  ;  ecls   = [ExpectHoverText ["Num"], ExpectExternFail]
   in
   mkFindTests
   --     def    hover  look   expect
@@ -793,12 +795,15 @@ findDefinitionAndHoverTests = let
   , test yes    yes    dcL12  tcDC   "plain  data constructor"       -- 121
   , test yes    broken tcL6   tcData "type constructor"              -- 147
   , test broken broken xtcL5  xtc    "type constructor from other package"
-  , test broken yes    xvL20  xvMsg  "value from other package"
-  , test yes    yes    vvL16  vv     "plain parameter"
-  , test yes    yes    aL18   apmp   "pattern match name"
-  , test yes    yes    opL16  op     "top-level operator"            -- 123
-  , test yes    yes    opL18  opp    "parameter operator"
-  , test yes    yes    b'L19  bp     "name in backticks"
+  , test broken yes    xvL20  xvMsg  "value from other package"      -- 120
+  , test yes    yes    vvL16  vv     "plain parameter"               -- 120
+  , test yes    yes    aL18   apmp   "pattern match name"            -- 120
+  , test yes    yes    opL16  op     "top-level operator"            -- 120, 123
+  , test yes    yes    opL18  opp    "parameter operator"            -- 120
+  , test yes    yes    b'L19  bp     "name in backticks"             -- 120
+  , test yes    broken clL23  cls    "class in instance declaration"
+  , test yes    broken clL25  cls    "class in signature"            -- 147
+  , test broken broken eclL15 ecls   "external class in signature"
   ]
   where yes, broken :: (TestTree -> Maybe TestTree)
         yes    = Just -- test should run and pass