Send an event before leave buffer in window

python3/vimspector/debug_session.py

@@ -710,7 +710,6 @@ class DebugSession( object ):
     self._stackTraceView.SetSyntax( self._codeView.current_syntax )
     self._variablesView.LoadScopes( frame )
     self._variablesView.EvaluateWatches()
-    vim.command( 'doautocmd <nomodeline> User VimspectorFrameWasSet' )
 
     if reason == 'stopped':
       self._breakpoints.ClearTemporaryBreakpoint( frame[ 'source' ][ 'path' ],

python3/vimspector/utils.py

@@ -76,7 +76,14 @@ def WindowForBuffer( buf ):
 def OpenFileInCurrentWindow( file_name ):
   buffer_number = BufferNumberForFile( file_name )
   try:
+    if "vimspectorStep" in vim.current.buffer.vars:
+      del vim.current.buffer.vars["vimspectorStep"]
+      # @todo: what if the same buffer is still visited by another thread
+      vim.command( 'doautocmd <nomodeline> User VimspectorFrameLeavePre' )
+
     vim.current.buffer = vim.buffers[ buffer_number ]
+    vim.current.buffer.vars["vimspectorStep"] = 1
+    vim.command( 'doautocmd <nomodeline> User VimspectorFrameWasSet' )
   except vim.error as e:
     if 'E325' not in str( e ):
       raise

tests/ui.test.vim

@@ -410,16 +410,16 @@ function! Test_CustomWinBar()
   %bwipe!
 endfunction
 
-function! Test_VimspectorFrameWasSet()
-  augroup TestVimspectorFrameWasSet
+function! Test_VimspectorFrameEnter()
+  augroup TestVimspectorFrameEnter
     au!
-    au User VimspectorFrameWasSet let b:vimspectorStepIsThere = 'foo'
+    au User VimspectorFrameEnter let b:vimspectorStepIsThere = 'foo'
   augroup END
 
   call s:StartDebugging()
   call assert_equal( 'foo', getbufvar(bufnr(), 'vimspectorStepIsThere', 0) )
 
-  au! TestVimspectorFrameWasSet
+  au! TestVimspectorFrameEnter
   unlet b:vimspectorStepIsThere
   call vimspector#test#setup#Reset()
   %bwipe!