How to prevent snippets with multiple references from clobbering the completion menu?

[unphased]

See the writeup I did here: dcampos/nvim-snippy#116

Basically when you have a snippet (even a simple one) that references one of the tabstops, e.g. the following snippet:

console.log("$1", $1)

what happens with cmp and the snippet engine is that as you use the cmp completion menu to select an item, the instant it's selected, cmp fills it into the buffer, which in turn causes the snippet engine to fill in the second instance of $1, which in turn presumably requires the cursor to move, which presumably causes cmp to clobber its understanding of which characters you've typed (now thinking that the completion that got selected became actually fully typed in).

Hopefully an elegant workaround exists for this. I worry that the limitation is in cmp's side and the same issue will exist no matter what snippet engine is used.

I suspect that using cmp.SelectBehavior.Select instead of cmp.SelectBehavior.Insert may address this but I don't want to have to add another keystroke.

Maybe the answer that will be mildly satisfactory will be to query snippet engine during this logic and only use the Select mode when a snippet is active.

[unphased]

Yeah.

only use the Select mode when a snippet is active

works.

Here's my relevant mapping logic which may be helpful to anyone in the same boat.

  mapping = cmp.mapping.preset.insert({
    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    --- removing c-space from cmp behavior to make room for it for copilot
    -- ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-e>'] = cmp.mapping.abort(),
    ["<CR>"] = cmp.mapping.confirm({
      behavior = cmp.ConfirmBehavior.Replace,
      select = false,
    }),
    ["<Tab>"] = cmp.mapping(function(fallback)
      if cmp.visible() then
        if require'snippy'.can_expand_or_advance() then
          log('using select behavior select')
          cmp.select_next_item({ behavior = cmp.SelectBehavior.Select })
        else
          log('using select behavior insert')
          cmp.select_next_item({ behavior = cmp.SelectBehavior.Insert })
        end
      elseif require'snippy'.can_expand_or_advance() then
        log('snippy calling expand_or_advance')
        require'snippy'.expand_or_advance()
      elseif has_words_before() then
        log('has_words_before produced '..vim.inspect(has_words_before()))
        cmp.complete()
      else
        log('cmp calling fallback')
        fallback()
      end
    end, { "i", "s" }),

    ["<S-Tab>"] = cmp.mapping(function(fallback)
      if cmp.visible() then
        if require'snippy'.can_expand_or_advance() then
          log('using select behavior select')
          cmp.select_prev_item({ behavior = cmp.SelectBehavior.Select })
        else
          log('using select behavior insert')
          cmp.select_prev_item({ behavior = cmp.SelectBehavior.Insert })
        end
      elseif require'snippy'.can_jump(-1) then
        require'snippy'.previous()
      else
        fallback()
      end
    end, { "i", "s" }),
  }),