Is it possible to refresh LSP diagnostics when opening a buffer?

[FelixLisczyk]

Hi,

I've created a new iOS project in Xcode (attached below) and changed the view reference from ContentView to ContentView1 to trigger an LSP error. However, when I quit Neovim and reopen the file, the error is no longer visible. The moment I enter insert mode and make any change, the error reappears.

I know I can view build errors using the quick fix list (which is a great feature!), but I'd like them to appear in the buffer without having to make an edit. Is this possible?

Notes

• I tested this with the starter config to rule out any configuration issues on my end.
• I've read your comment about different types or errors. I've also tried building the project, restarting the LSP, and other troubleshooting steps, but the only way to make the errors reappear is by editing the file.
• I'm not sure if this is a problem with the plugin itself. Please let me know if I should open an issue with detailed reproduction steps.

Sample Project

LspError.zip

Screen Recording

neovim-lsp.mp4

[wojciech-kulik]

Hi, those marks are handled by the LSP. Probably, the first check is triggered on edit. Have you tried calilng :LspRestart? Maybe it will trigger the check. If it works, you could schedule it to run automatically when Neovim starts.

[FelixLisczyk]

Thanks for your quick response! I restarted the LSP server, but it didn't help. The only noticeable effect was that the syntax highlighting briefly disappeared.

Does the plugin send warnings and errors from the build log to the LSP diagnostics, or are they handled separately? My issue is that after a failed build, I use the quick fix list to open the source file, but no errors appear in the buffer. I always have to make a small edit to the file to trigger them, which gets a bit tedious over time.

[wojciech-kulik]

Build errors are detected by LSP, so the plugin does not display them in a buffer. However, the plugin does add them to the quickfix list. Therefore, when you open Neovim, you will see the errors in the quickfix list, but for some reason, LSP does not show them in the buffer. I noticed that using the command :e! forces LSP to recheck the buffer.

I'm not sure whether this is an issue with the nvim-lspconfig plugin or Neovim itself. I recommend asking about it in the nvim-lspconfig repository first, as they should have more insight into how it functions internally.

[FelixLisczyk]

I've discovered that reloading the buffer displays LSP diagnostics. The workaround below is a bit hacky, but it works for now. If anyone finds a better solution, please let me know! 😅

local last_buf = nil

-- Workaround to show LSP errors when opening a Swift file
vim.api.nvim_create_autocmd("BufEnter", {
  pattern = "*.swift",
  callback = function(ev)
    -- This check prevents an infinite loop
    -- Reloading the buffer causes another "BufEnter" event
    if last_buf ~= ev.buf then
      last_buf = ev.buf
      vim.defer_fn(function()
        -- This check avoids unnecessary flickering when navigating between buffers
        -- Reload the buffer only when there are build errors
        local quickfix_list = vim.fn.getqflist()
        if #quickfix_list > 0 then
          vim.cmd("e")
        end
      end, 250)
    end
  end,
})

[wojciech-kulik]

Hah, I've just noticed your answer. So you discovered the same thing :D