Marginally improve the hover text

Don't use the default padded display.
When the request fails, say why.
Include the type if known.

python3/vimspector/debug_adapter_connection.py

@@ -16,8 +16,13 @@
 import logging
 import json
 
+from collections import namedtuple
+
 from vimspector import utils
 
+PendingRequest = namedtuple( 'PendingRequest',
+                             [ 'msg', 'handler', 'failure_handler' ] )
+
 
 class DebugAdapterConnection( object ):
   def __init__( self, handler, send_func ):
@@ -29,16 +34,18 @@ class DebugAdapterConnection( object ):
     self._buffer = bytes()
     self._handler = handler
     self._next_message_id = 0
-    self._outstanding_requests = dict()
+    self._outstanding_requests = {}
 
-  def DoRequest( self, handler, msg ):
+  def DoRequest( self, handler, msg, failure_handler=None ):
     this_id = self._next_message_id
     self._next_message_id += 1
 
     msg[ 'seq' ] = this_id
     msg[ 'type' ] = 'request'
 
-    self._outstanding_requests[ this_id ] = handler
+    self._outstanding_requests[ this_id ] = PendingRequest( msg,
+                                                            handler,
+                                                            failure_handler )
     self._SendMessage( msg )
 
   def Reset( self ):
@@ -132,11 +139,11 @@ class DebugAdapterConnection( object ):
       return
 
     if message[ 'type' ] == 'response':
-      handler = self._outstanding_requests.pop( message[ 'request_seq' ] )
+      request = self._outstanding_requests.pop( message[ 'request_seq' ] )
 
       if message[ 'success' ]:
-        if handler:
-          handler( message )
+        if request.handler:
+          request.handler( message )
       else:
         reason = message.get( 'message' )
         if not message:
@@ -148,9 +155,10 @@ class DebugAdapterConnection( object ):
             message = 'No reason'
 
         self._logger.error( 'Request failed: {0}'.format( reason ) )
-        utils.UserMessage( 'Request failed: {0}'.format( reason ) )
-                           
-
+        if request.failure_handler:
+          request.failure_handler( reason, message )
+        else:
+          utils.UserMessage( 'Request failed: {0}'.format( reason ) )
     elif message[ 'type' ] == 'event':
       method = 'OnEvent_' + message[ 'event' ]
       if method in dir( self._handler ):

python3/vimspector/variables.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import vim
+import json
 from collections import namedtuple
 from functools import partial
 
@@ -92,8 +93,6 @@ class VariablesView( object ):
     for k, v in self._oldoptions.items():
       vim.options[ k ] = v
 
-    # TODO: delete the buffer?
-
   def LoadScopes( self, frame ):
     def scopes_consumer( message ):
       self._scopes = []
@@ -273,8 +272,23 @@ class VariablesView( object ):
       return
 
     def handler( message ):
-      vim.eval( "balloon_show( '{0}' )".format(
-        utils.Escape( message[ 'body' ][ 'result' ] ) ) )
+      # TODO: this result count be expandable, but we have no way to allow the
+      # user to interact with the balloon to expand it.
+      body = message[ 'body' ]
+      ref = body.get( 'variablesReference', 0 )
+      icon = '+ ' if ref > 0 else ''
+      display = [
+        'Type: ' + body.get( 'type', '<unknown>' ),
+        icon + 'Value: ' + body[ 'result' ]
+      ]
+      vim.eval( "balloon_show( {0} )".format(
+        json.dumps( display ) ) )
+
+    def failure_handler( reason, message ):
+      display = [ reason ]
+      vim.eval( "balloon_show( {0} )".format(
+        json.dumps( display ) ) )
+
 
     self._connection.DoRequest( handler, {
       'command': 'evaluate',
@@ -283,4 +297,4 @@ class VariablesView( object ):
         'frameId': frame[ 'id' ],
         'context': 'hover',
       }
-    } )
+    }, failure_handler )