Don't try to expand variables that are not expandable

python3/vimspector/debug_session.py

@@ -39,7 +39,7 @@ class DebugSession( object ):
 
     self._uiTab = None
     self._threadsBuffer = None # TODO: Move to stack trace
-    self._outputBuffer = None
+    self._outputBuffer = None # TODO: Need something less terrible here
     self._stackTraceView = None
     self._variablesView = None
 

python3/vimspector/variables.py

@@ -140,10 +140,19 @@ class VariablesView( object ):
       return
 
     variable = self._line_to_variable[ current_line ]
+
     if '_variables' in variable:
+      # Collapse
       del variable[ '_variables' ]
       self._DrawScopesAndWatches()
-    else:
+      return
+
+    # Expand. (only if there is anything to expand)
+    if 'variablesReference' not in variable:
+      return
+    if variable[ 'variablesReference' ] <= 0:
+      return
+
     self._connection.DoRequest( partial( self._ConsumeVariables, variable ), {
       'command': 'variables',
       'arguments': {