[NVIM] Make update checker portable

nvim/init.vim

@@ -32,9 +32,6 @@ let g:loaded_perl_provider = 0
 call plug#begin()
 
 if !exists('g:vscode')
-" Warn about plugin updates
-Plug 'semanser/vim-outdated-plugins'
-
 " Powerline replacement
 Plug 'vim-airline/vim-airline'
 Plug 'vim-airline/vim-airline-themes'
@@ -112,6 +109,136 @@ endif
 
 call plug#end()
 
+" Check for plugin updates after the editor is responsive.
+lua << EOF
+local function check_plugin_updates()
+    local plugins = {}
+    for name, plugin in pairs(vim.g.plugs or {}) do
+        if vim.fn.isdirectory(plugin.dir) == 1 then
+            table.insert(plugins, { name = name, dir = plugin.dir })
+        end
+    end
+    table.sort(plugins, function(a, b) return a.name < b.name end)
+
+    local next_plugin = 1
+    local active = 0
+    local finished = 0
+    local failures = 0
+    local updates = {}
+    local concurrency = 2
+
+    local function git_command(args)
+        local command = {}
+        if vim.fn.executable('ionice') == 1 then
+            vim.list_extend(command, { 'ionice', '-c', '3' })
+        end
+        if vim.fn.executable('nice') == 1 then
+            vim.list_extend(command, { 'nice', '-n', '10' })
+        end
+        table.insert(command, 'git')
+        vim.list_extend(command, args)
+        return command
+    end
+
+    local function set_airline_status(message)
+        vim.g.plugin_update_status = message
+        local marker = '%{get(g:,"plugin_update_status","")}'
+        local warning = vim.g.airline_section_warning or ''
+        if not string.find(warning, 'plugin_update_status', 1, true) then
+            vim.g.airline_section_warning = warning .. ' ' .. marker
+        end
+        if vim.fn.exists(':AirlineRefresh') == 2 then
+            vim.cmd('AirlineRefresh')
+        end
+    end
+
+    local function report()
+        if #updates > 0 then
+            set_airline_status(string.format('[updates: %d]', #updates))
+            local message = string.format(
+                '%d plugin update%s available: %s',
+                #updates,
+                #updates == 1 and '' or 's',
+                table.concat(updates, ', ')
+            )
+            if failures > 0 then
+                message = message .. string.format(' (%d check%s failed)', failures, failures == 1 and '' or 's')
+            end
+            vim.notify(message, failures > 0 and vim.log.levels.WARN or vim.log.levels.INFO)
+        elseif failures > 0 then
+            set_airline_status('[update check failed]')
+            vim.notify(
+                string.format('Plugin update check incomplete: %d check%s failed', failures, failures == 1 and '' or 's'),
+                vim.log.levels.WARN
+            )
+        else
+            set_airline_status('')
+            vim.notify('All plugins up-to-date', vim.log.levels.INFO)
+        end
+    end
+
+    local pump
+    local function complete_one()
+        active = active - 1
+        finished = finished + 1
+        if finished == #plugins then
+            report()
+        else
+            pump()
+        end
+    end
+
+    local function check_one(plugin)
+        active = active + 1
+        vim.system(
+            git_command({ '-C', plugin.dir, 'fetch', '--quiet', '--no-tags', 'origin' }),
+            { text = true, timeout = 20000 },
+            vim.schedule_wrap(function(fetch_result)
+                if fetch_result.code ~= 0 then
+                    failures = failures + 1
+                    complete_one()
+                    return
+                end
+
+                vim.system(
+                    git_command({ '-C', plugin.dir, 'rev-list', '--count', 'HEAD..@{upstream}' }),
+                    { text = true, timeout = 5000 },
+                    vim.schedule_wrap(function(count_result)
+                        local count = tonumber(vim.trim(count_result.stdout or ''))
+                        if count_result.code ~= 0 or count == nil then
+                            failures = failures + 1
+                        elseif count > 0 then
+                            table.insert(updates, plugin.name)
+                        end
+                        complete_one()
+                    end)
+                )
+            end)
+        )
+    end
+
+    pump = function()
+        while active < concurrency and next_plugin <= #plugins do
+            local plugin = plugins[next_plugin]
+            next_plugin = next_plugin + 1
+            check_one(plugin)
+        end
+    end
+
+    if #plugins > 0 then
+        pump()
+    end
+end
+
+vim.api.nvim_create_autocmd('VimEnter', {
+    group = vim.api.nvim_create_augroup('plugin_update_check', { clear = true }),
+    once = true,
+    callback = function()
+        vim.defer_fn(check_plugin_updates, 1500)
+    end,
+})
+EOF
+
 " Run PlugInstall if there are missing plugins
 autocmd VimEnter * if len(filter(values(g:plugs), '!isdirectory(v:val.dir)'))
   \| PlugInstall --sync | source $MYVIMRC