Allow choosing "which range" should be used when converting LSP Location-like objects

This fixes all of the remaining bugs when requesting outgoing calls of
an incoming call hierarchy item.

Specifically, we *want* `selectionRange` for the hierarchy root and for
`root_location` of incoming call hierarchy items.

JDT is special and needs `range` in the second case.

Author: bstaletic

ycmd/completers/java/java_completer.py

@@ -650,3 +650,18 @@ def GetServerName( self ):
 
   def GetCommandLine( self ):
     return self._command
+
+
+  def Hierarchy( self, request_data, args ):
+    # JDT.LS is a special snowflake and needs special snowflake treatement
+    # See: https://github.com/eclipse-jdtls/eclipse.jdt.ls/issues/3184
+    result = super().Hierarchy( request_data, args )
+    preparation_item, direction, kind = args
+    if kind == 'call' and direction == 'incoming':
+      for item in result:
+        # The base class does almost the same,
+        # but uses `selectionRange` instead of `range`.
+        item[ 'root_location' ] = responses.BuildGoToResponseFromLocation(
+          *language_server_completer._LspLocationToLocationAndDescription(
+            request_data, item[ 'from' ] ) )
+    return result

ycmd/completers/language_server/language_server_completer.py

@@ -2686,7 +2686,9 @@ def InitialHierarchy( self, request_data, args ):
 
     preparation_item[ 0 ][ 'locations' ] = [
       responses.BuildGoToResponseFromLocation(
-        *_LspLocationToLocationAndDescription( request_data, location ) )
+        *_LspLocationToLocationAndDescription( request_data,
+                                               location,
+                                               'selectionRange' ) )
       for location in preparation_item ]
     kind_string = lsp.SYMBOL_KIND[ preparation_item[ 0 ][ 'kind' ] ]
     preparation_item[ 0 ][ 'kind' ] = kind_string
@@ -2735,12 +2737,10 @@ def Hierarchy( self, request_data, args ):
             for location in lsp_locations ]
 
           if direction == 'incomingCalls':
-            loc = {
-              'uri': hierarchy_item[ 'uri' ],
-              'range': hierarchy_item[ 'range' ]
-            }
             item[ 'root_location' ] = responses.BuildGoToResponseFromLocation(
-              *_LspLocationToLocationAndDescription( request_data, loc ) )
+              *_LspLocationToLocationAndDescription( request_data,
+                                                     hierarchy_item,
+                                                     'selectionRange' ) )
         else:
           item[ 'kind' ] = lsp.SYMBOL_KIND[ item[ 'kind' ] ]
           item[ 'locations' ] = [
@@ -3396,7 +3396,9 @@ def BuildGoToLocationFromSymbol( symbol ):
     return locations
 
 
-def _LspLocationToLocationAndDescription( request_data, location ):
+def _LspLocationToLocationAndDescription( request_data,
+                                          location,
+                                          range_property = 'range' ):
   """Convert a LSP Location to a ycmd location."""
   try:
     filename = lsp.UriToFilePath( location[ 'uri' ] )
@@ -3413,9 +3415,10 @@ def _LspLocationToLocationAndDescription( request_data, location ):
                       'GoTo location' )
     file_contents = []
 
+  range = location[ range_property ]
   return _BuildLocationAndDescription( filename,
                                        file_contents,
-                                       location[ 'range' ][ 'start' ] )
+                                       range[ 'start' ] )
 
 
 def _LspToYcmdLocation( file_contents, location ):

ycmd/tests/rust/subcommands_test.py

@@ -635,14 +635,14 @@ def test_Subcommands_IncomingCallHierarchy( self, app ):
                            LocationMatcher( filepath, 6, 11 ) ),
             # rust-analyzer always returns column 1 for root_location,
             # which is useless for us... unfortunately.
-            'root_location': LocationMatcher( filepath, 5, 1 )
+            'root_location': LocationMatcher( filepath, 5, 4 )
           } ),
           has_entries( {
             'locations': contains_exactly(
                            LocationMatcher( filepath, 11, 5 ) ),
             # rust-analyzer always returns column 1 for root_location,
             # which is useless for us... unfortunately.
-            'root_location': LocationMatcher( filepath, 9, 1 )
+            'root_location': LocationMatcher( filepath, 9, 4 )
           } )
         ),
         requests.codes.ok ],
@@ -653,7 +653,7 @@ def test_Subcommands_IncomingCallHierarchy( self, app ):
                            LocationMatcher( filepath, 10, 13 ) ),
             # rust-analyzer always returns column 1 for root_location,
             # which is useless for us... unfortunately.
-            'root_location': LocationMatcher( filepath, 9, 1 )
+            'root_location': LocationMatcher( filepath, 9, 4 )
           } )
         ),
         requests.codes.ok ],