feat(nvim): add copilot to nvim-cmp

additionally move nvim-cmp plugin to its own file

3 files changed, 185 insertions, 32 deletions

diff --git a/.chezmoi.toml.tmpl b/.chezmoi.toml.tmpl
index f9a8b7a..5f8c013 100644
--- a/.chezmoi.toml.tmpl
+++ b/.chezmoi.toml.tmpl
@@ -15,6 +15,8 @@
 {{ $git_email := promptStringOnce . "git_email" "Email address for Git global config" -}}
 {{ $git_name := promptStringOnce . "git_name" "Display name for Git global config" -}}
 
+{{ $enable_nvim_copilot := promptBoolOnce . "enable_nvim_copilot" "Enable features related to GitHub Copilot" -}}
+
 {{ if eq .chezmoi.os "windows" -}}
 [cd]
     command = "pwsh"
@@ -26,6 +28,7 @@
 [data]
     git_email = {{ $git_email | quote }}
     git_name = {{ $git_name | quote }}
+    enable_nvim_copilot = {{ $enable_nvim_copilot }}
 
 [diff]
     exclude = ["scripts"]
diff --git a/dot_config/nvim/lua/plugins/lsp-zero.lua b/dot_config/nvim/lua/plugins/lsp-zero.lua
index a234493..67ea808 100644
--- a/dot_config/nvim/lua/plugins/lsp-zero.lua
+++ b/dot_config/nvim/lua/plugins/lsp-zero.lua
@@ -18,44 +18,16 @@ return {
         config = true,
     },
 
-    -- Autocompletion
-    {
-        'hrsh7th/nvim-cmp',
-        event = 'InsertEnter',
-        dependencies = {
-            { 'L3MON4D3/LuaSnip' },
-        },
-        config = function()
-            -- Here is where you configure the autocompletion settings.
-            local lsp_zero = require('lsp-zero')
-            lsp_zero.extend_cmp()
-
-            -- And you can configure cmp even more, if you want to.
-            local cmp = require('cmp')
-            local cmp_action = lsp_zero.cmp_action()
-
-            cmp.setup({
-                formatting = lsp_zero.cmp_format({details = true}),
-                mapping = cmp.mapping.preset.insert({
-                    ['<C-Space>'] = cmp.mapping.complete(),
-                    ['<C-u>'] = cmp.mapping.scroll_docs(-8),
-                    ['<C-d>'] = cmp.mapping.scroll_docs(8),
-                    -- ['<C-f>'] = cmp.mapping.luasnip_jump_forward(),
-                    -- ['<C-b>'] = cmp.mapping.luasnip_jump_backward(),
-                })
-            })
-        end
-    },
 
     -- LSP
     {
         'neovim/nvim-lspconfig',
-        cmd = {'LspInfo', 'LspInstall', 'LspStart'},
-        event = {'BufReadPre', 'BufNewFile'},
+        cmd = { 'LspInfo', 'LspInstall', 'LspStart' },
+        event = { 'BufReadPre', 'BufNewFile' },
         dependencies = {
             { 'hrsh7th/cmp-nvim-lsp' },
             { 'williamboman/mason-lspconfig.nvim' },
-            { "j-hui/fidget.nvim", tag = "legacy", opts = {} },
+            { "j-hui/fidget.nvim",                tag = "legacy", opts = {} },
         },
         config = function()
             -- This is where all the LSP shenanigans will live
@@ -67,7 +39,7 @@ return {
             lsp_zero.on_attach(function(client, bufnr)
                 -- see :help lsp_zero_keybindings
                 -- to learn the available actions
-                lsp_zero.default_keymaps({buffer = bufnr})
+                lsp_zero.default_keymaps({ buffer = bufnr })
             end)
 
             require('mason-lspconfig').setup({
diff --git a/dot_config/nvim/lua/plugins/nvim-cmp.lua.tmpl b/dot_config/nvim/lua/plugins/nvim-cmp.lua.tmpl
new file mode 100644
index 0000000..60c77d3
--- /dev/null
+++ b/dot_config/nvim/lua/plugins/nvim-cmp.lua.tmpl
@@ -0,0 +1,178 @@
+-- {{/*
+-- vim:ft=lua
+-- This file supports Go's text/template language.
+--
+-- My work role allows me to use an enterprise subscription to GitHub
+-- Copilot, but I don't pay to use this personally.
+--
+-- Since copilot.lua is integrated tightly into nvim-cmp, using a
+-- Chezmoi template is the easiest way to manage this machine-specific
+-- difference.
+--
+-- Unfortunately, it's tough to get an editor to treat this as both
+-- a Go template and as a Lua file. I compromise by calling it a Lua
+-- file and wrapping template directives in Lua comments. This has the
+-- side effect of adding a few extra random dash characters to the
+-- rendered file, but I don't mind.
+-- */}}
+
+-- Optional features:
+-- * GitHub Copilot: {{ .enable_nvim_copilot }}
+--
+-- To adjust optional features, see the Chezmoi config at {{ .chezmoi.configFile }}
+
+return {
+    "hrsh7th/nvim-cmp",
+    version = false, -- last release is way too old
+    event = { "InsertEnter", "CmdlineEnter" },
+    dependencies = {
+        "L3MON4D3/LuaSnip",             -- Snippet engine
+        "rafamadriz/friendly-snippets", -- Useful snippets in VSCode snippet format
+        "onsails/lspkind.nvim",         -- Pretty formatting in the completion menu
+
+        -- Completion sources
+        "hrsh7th/cmp-nvim-lsp",
+        "hrsh7th/cmp-nvim-lsp-signature-help",
+        "hrsh7th/cmp-buffer",
+        "hrsh7th/cmp-path",
+        "saadparwaiz1/cmp_luasnip",
+
+        -- {{ if eq .enable_nvim_copilot true -}}
+        -- GitHub Copilot
+        "zbirenbaum/copilot.lua",
+        "zbirenbaum/copilot-cmp",
+        -- {{- end }}
+    },
+    config = function()
+        local cmp = require("cmp")
+        local luasnip = require("luasnip")
+
+        -- Load any VSCode-style snippets from other installed plugins
+        require("luasnip.loaders.from_vscode").lazy_load()
+
+        -- {{ if eq .enable_nvim_copilot true -}}
+        -- Init Copilot
+        require("copilot").setup({
+            suggestion = { enabled = false },
+            panel = { enabled = false },
+        })
+        require("copilot_cmp").setup()
+        -- {{ end }}
+
+        cmp.setup({
+            completion = {
+                -- See :help completeopt
+                completeopt = "menu,menuone,noinsert,preview",
+            },
+            snippet = {
+                expand = function(args)
+                    luasnip.lsp_expand(args.body)
+                end,
+            },
+            mapping = cmp.mapping.preset.insert({
+                ["<C-n>"] = cmp.mapping.select_next_item({ behavior = cmp.SelectBehavior.Insert }),
+                ["<C-p>"] = cmp.mapping.select_prev_item({ behavior = cmp.SelectBehavior.Insert }),
+                ["<C-b>"] = cmp.mapping.scroll_docs(-4),
+                ["<C-f>"] = cmp.mapping.scroll_docs(4),
+
+                -- Ctrl+Space does not currently work in Neovim core on Windows
+                -- https://github.com/neovim/neovim/issues/8435
+                -- ["<C-Space>"] = cmp.mapping.complete(),
+                ["<C-c>"] = cmp.mapping.complete(),
+
+                ["<C-e>"] = cmp.mapping.abort(),
+                ["<C-y>"] = cmp.mapping.confirm({
+                    -- Accept currently selected item
+                    behavior = cmp.ConfirmBehavior.Insert,
+                    select = true,
+                }),
+                ["<C-S-y>"] = cmp.mapping.confirm({
+                    -- Accept currently selected item, replacing stuff as needed
+                    behavior = cmp.ConfirmBehavior.Replace,
+                    select = true,
+                }),
+                ["<CR>"] = cmp.mapping({
+                    -- https://github.com/hrsh7th/nvim-cmp/wiki/Example-mappings#safely-select-entries-with-cr
+                    i = function(fallback)
+                        -- In insert mode, only use Enter to complete something if cmp
+                        -- is active and the user has explicitly selected an item
+                        if cmp.visible() and cmp.get_active_entry() then
+                            cmp.confirm({ behavior = cmp.ConfirmBehavior.Replace, select = false })
+                        else
+                            fallback()
+                        end
+                    end,
+                    s = cmp.mapping.confirm({ select = true }),
+                    c = cmp.mapping.confirm({ behavior = cmp.ConfirmBehavior.Replace, select = true }),
+                }),
+            }),
+            sorting = {
+                priority_weight = 2,
+                comparators = {
+                    cmp.config.compare.exact,
+
+                    -- {{ if eq .enable_nvim_copilot true -}}
+                    -- Custom comparitor from copilot_cmp
+                    require("copilot_cmp.comparators").prioritize,
+                    -- {{ end -}}
+
+                    -- Mostly default sort order from cmp
+                    cmp.config.compare.offset,
+                    -- cmp.config.compare.scopes, --this is commented in nvim-cmp too
+                    cmp.config.compare.score,
+                    cmp.config.compare.recently_used,
+                    cmp.config.compare.locality,
+                    cmp.config.compare.kind,
+                    cmp.config.compare.sort_text,
+                    cmp.config.compare.length,
+                    cmp.config.compare.order,
+                },
+            },
+            sources = {
+                -- LSP results should be first priority
+                { name = "nvim_lsp",                group_index = 1 },
+
+                { name = "nvim_lsp_signature_help", group_index = 2 },
+                { name = "luasnip",                 group_index = 2 },
+                -- {{ if eq .enable_nvim_copilot true }}
+                { name = "copilot",                 group_index = 2 },
+                -- {{ end }}
+                { name = "path",                    group_index = 2 },
+                { name = "buffer",                  group_index = 2, keyword_length = 5 },
+            },
+            -- sources = cmp.config.sources({
+            --     { name = "nvim_lsp_signature_help" },
+            --     { name = "nvim_lsp" },
+            --     { name = "luasnip" },
+            -- }, {
+            --     { name = "path" },
+            --     { name = "buffer", keyword_length = 5 },
+            -- }),
+            formatting = {
+                format = require("lspkind").cmp_format({
+                    mode = "symbol_text",
+                    -- maxwidth = 50,
+                    maxwidth = function()
+                        return math.floor(0.45 * vim.o.columns)
+                    end,
+                    ellipsis_char = "...",
+                    show_labelDetails = true,
+                    symbol_map = {
+                        -- {{ if eq .enable_nvim_copilot true }}
+                        Copilot = " ",
+                        -- {{ end }}
+                    },
+                }),
+            },
+            experimental = {
+                ghost_text = {
+                    hl_group = "LspCodeLens",
+                },
+            },
+            window = {
+                completion = cmp.config.window.bordered(),
+                documentation = cmp.config.window.bordered(),
+            },
+        })
+    end,
+}