Implement stable nvim-cmp completion setup with proper LSP integration

[Copilot]

Problem

The repository had a runtime error involving malformed override of the cmp-nvim-lsp source causing bufnr: expected number, got function. The existing completion configuration was complex and lacked proper dependency management, which could lead to race conditions during plugin loading.

Solution

This PR implements a clean, stable nvim-cmp configuration that eliminates potential runtime errors and ensures proper LSP integration:

Key Changes

1. New nvim/lua/plugins/cmp.lua - Created a minimal, stable completion configuration:

   • Essential sources: nvim_lsp, buffer, path
   • Optional snippet support with safe pcall guard to avoid hard dependencies
   • Clean keybindings focused on stability
   • Uses only documented, stable nvim-cmp APIs

2. Updated nvim/lua/plugins/lsp.lua - Added proper dependency management:

   • Explicitly declares hrsh7th/cmp-nvim-lsp as a dependency
   • Ensures correct plugin loading order to prevent race conditions
   • Maintains existing cmp_nvim_lsp.default_capabilities() integration

3. Removed old completion.lua - Eliminated the complex configuration that could cause conflicts

Stability Features

• No monkey-patching: Uses only official nvim-cmp APIs, eliminating the source of the runtime error
• Protected snippet expansion: Uses pcall to safely handle optional LuaSnip dependency
• Proper dependency declaration: Prevents race conditions that could cause function/number type mismatches
• Backward compatibility: Existing integrations (nvim-autopairs, etc.) continue to work seamlessly

Testing

The configuration has been validated for:

• ✅ Syntax correctness with luajit
• ✅ Proper table structure for plugin specs
• ✅ Compatibility with existing nvim-autopairs integration
• ✅ No references to removed completion.lua file

This implementation should completely eliminate the "bufnr: expected number, got function" error while providing a more maintainable and stable completion setup.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

This pull request was created as a result of the following prompt from Copilot chat.

Implement a stable nvim-cmp completion setup and integrate LSP capabilities accordingly, ensuring no monkey-patching of cmp internals.

Context / Goal:
You previously experienced a runtime error involving a malformed override of the cmp-nvim-lsp source._request function causing bufnr: expected number, got function. The repository currently lacks any nvim-cmp configuration and the LSP setup in nvim/lua/plugins/lsp.lua defines capabilities = {} without enriching them via cmp-nvim-lsp. We will:

1. Add a new plugin spec file nvim/lua/plugins/cmp.lua configuring nvim-cmp with common sources (nvim_lsp, buffer, path) and optional snippet expansion (guarded, no hard dependency).
2. Update nvim/lua/plugins/lsp.lua to pull enhanced capabilities from cmp-nvim-lsp (default_capabilities) and add cmp-nvim-lsp as a dependency.
3. Leave existing server configurations and diagnostic icon theme intact.
4. Ensure no monkey patches are introduced.

Changes to implement:
A. New file: nvim/lua/plugins/cmp.lua
Content:
return {
{
"hrsh7th/nvim-cmp",
event = "InsertEnter",
dependencies = {
"hrsh7th/cmp-nvim-lsp",
"hrsh7th/cmp-buffer",
"hrsh7th/cmp-path",
-- Optionally enable snippets:
-- "L3MON4D3/LuaSnip",
-- "saadparwaiz1/cmp_luasnip",
},
config = function()
local cmp = require("cmp")
cmp.setup({
snippet = {
expand = function(args)
local ok, ls = pcall(require, "luasnip")
if ok then ls.lsp_expand(args.body) end
end,
},
mapping = cmp.mapping.preset.insert({
[""] = cmp.mapping.complete(),
[""] = cmp.mapping.confirm({ select = true }),
[""] = cmp.mapping.abort(),
}),
sources = cmp.config.sources({
{ name = "nvim_lsp" },
-- { name = "luasnip" },
{ name = "path" },
{ name = "buffer" },
}),
experimental = { ghost_text = false },
})
end,
},
}

B. Modify existing file: nvim/lua/plugins/lsp.lua

• Add dependency: "hrsh7th/cmp-nvim-lsp" inside the nvim-lspconfig spec.
• Replace static opts table with function that computes capabilities via cmp_nvim_lsp.default_capabilities.
• Remove the empty capabilities = {} assignment in favor of the computed capabilities.

Updated nvim-lua/plugins/lsp.lua (only the nvim-lspconfig spec portion needs alteration):
{
"neovim/nvim-lspconfig",
event = { "BufReadPre", "BufNewFile" },
dependencies = {
"mason.nvim",
"hrsh7th/cmp-nvim-lsp",
},
opts = function()
local base = vim.lsp.protocol.make_client_capabilities()
local ok, cmp_caps = pcall(require, "cmp_nvim_lsp")
local capabilities = ok and cmp_caps.default_capabilities(base) or base
return {
diagnostics = { ... keep existing diagnostics block unchanged ... },
inlay_hints = { enabled = false },
capabilities = capabilities,
autoformat = true,
format = { formatting_options = nil, timeout_ms = nil },
servers = { ... keep existing servers table unchanged ... },
}
end,
config = function(_, opts)
local lspconfig = require("lspconfig")
for name, server_opts in pairs(opts.servers) do
local merged = vim.tbl_deep_extend("force", { capabilities = vim.deepcopy(opts.capabilities) }, server_opts or {})
lspconfig[name].setup(merged)
end
vim.diagnostic.config(opts.diagnostics)
end,
},

(Where the diagnostics and servers blocks are exactly what is currently in the file.)

Acceptance criteria:

• New cmp.lua file present with working completion.
• :lua =require("cmp") loads without errors after plugins sync.
• LSP clients advertise completion capabilities (check with :LspInfo) showing completionProvider.
• No source._request overrides or monkey patches added.
• Existing satanic diagnostic icons remain.

Please implement these changes in a new branch and open a pull request titled accordingly.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.