Diagnostics Cleared on :e in nvim-metals

[todesking]

Hello,
I encountered an issue with diagnostics in nvim-metals, and I'm not sure if this is a problem with nvim-metals itself or something specific to my environment. Here are the steps to reproduce:

1. Open a Scala file with some errors/warnings.
2. Once the LSP attaches, diagnostics are displayed in the buffer as expected.
3. Execute :e to reload the file.
4. The diagnostics are cleared and do not reappear.

To address this, I implemented a "force-reloading" mechanism in the on_attach function as shown below, and it seems to resolve the issue for me:

metals_config.on_attach = function(client, bufnr)
  local doc = vim.lsp.util.make_text_document_params()
  doc.version = 0
  local params = {
    textDocument = doc,
    contentChanges = {
      {
        text = table.concat(vim.api.nvim_buf_get_lines(bufnr, 0, -1, true), "\n")
      }
    },
  }
  local handler = function(ress)
  end
  vim.lsp.buf_request_all(0, 'textDocument/didChange', params, handler)
end

While this workaround resolves the issue for me, I wonder:

• Is this behavior expected in nvim-metals?
• Am I possibly missing some configuration that could prevent diagnostics from being cleared on :e?

Any insights or advice would be greatly appreciated.

Thanks!

[ckipp01]

Hey @todesking thanks for reporting this. Something is definitely wrong here and the behavior wasn't always this way. I'm not sure if this is something that changed on the Metals side or on the Nvim side. What is happening is when you do a :e a textDocument/didClose is sent to Metals and then a textDocument/didOpen is sent to Metals. There are then no diagnostics published. However, that sort of makes sense since the diagnostics were already published and it seems that nvim just loses them, which I wouldn't expect. I need to dig a bit to see if Metals should actually republish them here ( I don't think so ) or better understand why when you close the document Nvim seems to throw away the diagnostics for the buffer when it closes.

[ckipp01]

I ended up created neovim/neovim#32247 for this @todesking. Feel free to follow along there.