refactor(snippet): rework luasnip source

doc/configuration/reference.md

@@ -581,7 +581,7 @@ sources.providers = {
       -- Whether to show autosnippets in the completion list
       show_autosnippets = true,
       -- Whether to prefer docTrig placeholders over trig when expanding regTrig snippets
-      prefer_doc_trig = false,
+      prefer_doc_trig = true,
       -- Whether to put the snippet description in the label description
       use_label_description = false,
     }

lua/blink/cmp/sources/lib/init.lua

@@ -107,13 +107,6 @@ function sources.get_enabled_providers(mode)
 end
 
 function sources.get_provider_by_id(provider_id)
-  -- TODO: remove in v1.0
-  if not sources.providers[provider_id] and provider_id == 'luasnip' then
-    error(
-      "Luasnip has been moved to the `snippets` source, alongside a new preset system (`snippets.preset = 'luasnip'`). See the documentation for more information."
-    )
-  end
-
   assert(
     sources.providers[provider_id] ~= nil or config.sources.providers[provider_id] ~= nil,
     'Requested provider "'

lua/blink/cmp/sources/snippets/luasnip.lua

@@ -1,95 +1,180 @@
+---@type LuaSnip.API
+local luasnip
+local cmp = require('blink.cmp')
+local utils = require('blink.cmp.lib.utils')
+local text_edits = require('blink.cmp.lib.text_edits')
+local kind_snippet = require('blink.cmp.types').CompletionItemKind.Snippet
+
 --- @class blink.cmp.LuasnipSourceOptions
 --- @field use_show_condition? boolean Whether to use show_condition for filtering snippets
 --- @field show_autosnippets? boolean Whether to show autosnippets in the completion list
---- @field prefer_doc_trig? boolean When expanding `regTrig` snippets, prefer `docTrig` over `trig` placeholder
+--- @field prefer_doc_trig? boolean When expanding `regTrig` snippets, prefer `docTrig` over `trig` placeholder (deprecated)
 --- @field use_label_description? boolean Whether to put the snippet description in the label description
 
 --- @class blink.cmp.LuasnipSource : blink.cmp.Source
---- @field config blink.cmp.LuasnipSourceOptions
+--- @field opts blink.cmp.LuasnipSourceOptions
 --- @field items_cache table<string, blink.cmp.CompletionItem[]>
-
-local utils = require('blink.cmp.lib.utils')
-
---- @type blink.cmp.LuasnipSource
---- @diagnostic disable-next-line: missing-fields
+--- @field has_loaded boolean
 local source = {}
 
-local default_config = {
-  use_show_condition = true,
-  show_autosnippets = true,
-  prefer_doc_trig = false,
-  use_label_description = false,
-}
-
 ---@param snippet table
----@param event string
+---@param event number
 ---@param callback fun(table, table)
 local function add_luasnip_callback(snippet, event, callback)
-  local events = require('luasnip.util.events')
   -- not defined for autosnippets
   if snippet.callbacks == nil then return end
   snippet.callbacks[-1] = snippet.callbacks[-1] or {}
-  snippet.callbacks[-1][events[event]] = callback
+  snippet.callbacks[-1][event] = callback
 end
 
+---@param snippet LuaSnip.Snippet
+local function regex_callback(snippet, docTrig)
+  if #snippet.insert_nodes == 0 then
+    snippet.insert_nodes[0].static_text[1] = docTrig
+    return
+  end
+
+  local matches = { string.match(docTrig, snippet.trigger) }
+  for i, match in ipairs(matches) do
+    local idx = i ~= #matches and i or 0
+    snippet.insert_nodes[idx].static_text[1] = match
+  end
+end
+
+---@param snippet LuaSnip.Snippet
+local function choice_callback(snippet, events)
+  local types = require('luasnip.util.types')
+
+  for _, node in ipairs(snippet.insert_nodes) do
+    if node.type == types.choiceNode then
+      node.node_callbacks = {
+        [events.enter] = function(n)
+          --[[@cast n LuaSnip.ChoiceNode]]
+          n:set_text({ '' }) -- NOTE: Clear the current text, we'll restore it when leaving the node. Available since v2.4.1
+          local index = utils.find_idx(n.choices, function(choice) return choice == n.active_choice end)
+          vim.schedule(function() cmp.show({ initial_selected_item_idx = index, providers = { 'snippets' } }) end)
+        end,
+        [events.change_choice] = function()
+          vim.schedule(function() luasnip.jump(1) end)
+        end,
+        [events.leave] = function(n)
+          --[[@cast n LuaSnip.ChoiceNode]]
+          n:set_text(n.active_choice.static_text)
+        end,
+      }
+    end
+  end
+end
+
+---@param snippet LuaSnip.Snippet
+---@return string?
+local function get_insert_text(snippet)
+  if snippet.docTrig then return snippet.docTrig end
+
+  local types = require('luasnip.util.types')
+  local res = {}
+  for _, node in ipairs(snippet.nodes) do
+    if node.static_text then
+      res[#res + 1] = table.concat(node:get_static_text(), '\n')
+    elseif vim.tbl_contains({ types.dynamicNode, types.functionNode }, node.type) then
+      res[#res + 1] = 'xxxxxxx'
+    end
+  end
+
+  return #res == 1 and snippet.trigger or table.concat(res, '')
+end
+
+---@param opts blink.cmp.LuasnipSourceOptions
 function source.new(opts)
-  local config = vim.tbl_deep_extend('keep', opts, default_config)
+  local self = setmetatable({}, { __index = source })
+
+  opts = vim.tbl_deep_extend('keep', opts or {}, {
+    use_show_condition = true,
+    show_autosnippets = true,
+    prefer_doc_trig = true, -- TODO: Remove in v2.0
+    use_label_description = false,
+  })
   require('blink.cmp.config.utils').validate('sources.providers.snippets.opts', {
-    use_show_condition = { config.use_show_condition, 'boolean' },
-    show_autosnippets = { config.show_autosnippets, 'boolean' },
-    prefer_doc_trig = { config.prefer_doc_trig, 'boolean' },
-    use_label_description = { config.use_label_description, 'boolean' },
-  }, config)
+    use_show_condition = { opts.use_show_condition, 'boolean' },
+    show_autosnippets = { opts.show_autosnippets, 'boolean' },
+    prefer_doc_trig = { opts.prefer_doc_trig, 'boolean' }, -- TODO: Remove in v2.0
+    use_label_description = { opts.use_label_description, 'boolean' },
+  }, opts)
 
-  local self = setmetatable({}, { __index = source })
-  self.config = config
+  self.opts = opts
   self.items_cache = {}
+  self.has_loaded = false
 
-  local luasnip_ag = vim.api.nvim_create_augroup('BlinkCmpLuaSnipReload', { clear = true })
-  vim.api.nvim_create_autocmd('User', {
-    pattern = 'LuasnipSnippetsAdded',
-    callback = function() self:reload() end,
-    group = luasnip_ag,
-    desc = 'Reset internal cache of luasnip source of blink.cmp when new snippets are added',
-  })
-  vim.api.nvim_create_autocmd('User', {
-    pattern = 'LuasnipCleanup',
-    callback = function() self:reload() end,
-    group = luasnip_ag,
-    desc = 'Reload luasnip source of blink.cmp when snippets are cleared',
-  })
+  local ok, mod = pcall(require, 'luasnip')
+  if ok then
+    self.has_loaded = true
+    luasnip = mod
+
+    local luasnip_ag = vim.api.nvim_create_augroup('BlinkCmpLuaSnipReload', { clear = true })
+    local events = {
+      { pattern = 'LuasnipSnippetsAdded', desc = 'Clear the Luasnip cache in blink.cmp when new snippets are added' },
+      { pattern = 'LuasnipCleanup', desc = 'Clear the Luasnip cache in blink.cmp when snippets are cleared' },
+    }
+    for _, event in ipairs(events) do
+      vim.api.nvim_create_autocmd('User', {
+        pattern = event.pattern,
+        callback = function() self:reload() end,
+        group = luasnip_ag,
+        desc = event.desc,
+      })
+    end
+  end
 
   return self
 end
 
-function source:enabled()
-  local ok, _ = pcall(require, 'luasnip')
-  return ok
-end
+function source:enabled() return self.has_loaded end
 
+---@param ctx blink.cmp.Context
+---@param callback fun(result?: blink.cmp.CompletionResponse)
 function source:get_completions(ctx, callback)
   --- @type blink.cmp.CompletionItem[]
   local items = {}
 
-  -- gather snippets from relevant filetypes, including extensions
-  for _, ft in ipairs(require('luasnip.util.util').get_snippet_filetypes()) do
-    if self.items_cache[ft] then
+  if luasnip.choice_active() then
+    ---@type LuaSnip.ChoiceNode
+    local active_choice = luasnip.session.active_choice_nodes[ctx.bufnr]
+    for i, choice in ipairs(active_choice.choices) do
+      local text = choice:get_static_text()[1]
+      table.insert(items, {
+        label = text,
+        kind = kind_snippet,
+        insertText = text,
+        insertTextFormat = vim.lsp.protocol.InsertTextFormat.PlainText,
+        data = { snip_id = active_choice.parent.snippet.id, choice_index = i },
+      })
+    end
+    callback({ is_incomplete_forward = false, is_incomplete_backward = false, items = items })
+    return
+  end
+
+  local events = require('luasnip.util.events')
+
+  -- Else, gather snippets from relevant filetypes, including extensions
+  for _, ft in ipairs(luasnip.get_snippet_filetypes()) do
+    if self.items_cache[ft] and #self.items_cache[ft] > 0 then
       for _, item in ipairs(self.items_cache[ft]) do
         table.insert(items, utils.shallow_copy(item))
       end
       goto continue
     end
 
-    -- cache not yet available for this filetype
-    self.items_cache[ft] = {}
+    -- Cache not yet available for this filetype
+    self.items_cache[ft] = nil
+
     -- Gather filetype snippets and, optionally, autosnippets
-    local snippets = require('luasnip').get_snippets(ft, { type = 'snippets' })
-    if self.config.show_autosnippets then
-      local autosnippets = require('luasnip').get_snippets(ft, { type = 'autosnippets' })
+    local snippets = luasnip.get_snippets(ft, { type = 'snippets' })
+    if self.opts.show_autosnippets then
+      local autosnippets = luasnip.get_snippets(ft, { type = 'autosnippets' })
       for _, s in ipairs(autosnippets) do
-        add_luasnip_callback(s, 'enter', require('blink.cmp').hide)
+        add_luasnip_callback(s, events.enter, cmp.hide)
       end
-      snippets = require('blink.cmp.lib.utils').shallow_copy(snippets)
+      snippets = utils.shallow_copy(snippets)
       vim.list_extend(snippets, autosnippets)
     end
     snippets = vim.tbl_filter(function(snip) return not snip.hidden end, snippets)
@@ -100,6 +185,7 @@ function source:get_completions(ctx, callback)
       max_priority = math.max(max_priority, snip.effective_priority or 0)
     end
 
+    local ft_items = {}
     for _, snip in ipairs(snippets) do
       -- Convert priority of 1000 (with max of 8000) to string like "00007000|||asd" for sorting
       -- This will put high priority snippets at the top of the list, and break ties based on the trigger
@@ -108,27 +194,29 @@ function source:get_completions(ctx, callback)
 
       --- @type lsp.CompletionItem
       local item = {
-        kind = require('blink.cmp.types').CompletionItemKind.Snippet,
+        kind = kind_snippet,
         label = snip.regTrig and snip.name or snip.trigger,
-        insertText = self.config.prefer_doc_trig and snip.docTrig or snip.trigger,
+        insertText = get_insert_text(snip),
         insertTextFormat = vim.lsp.protocol.InsertTextFormat.PlainText,
         sortText = sort_text,
         data = { snip_id = snip.id, show_condition = snip.show_condition },
-        labelDetails = snip.dscr and self.config.use_label_description and {
+        labelDetails = snip.dscr and self.opts.use_label_description and {
           description = table.concat(snip.dscr, ' '),
         } or nil,
       }
-      -- populate snippet cache for this filetype
-      table.insert(self.items_cache[ft], item)
-      -- while we're at it, also populate completion items for this request
+      -- Populate snippet cache for this filetype
+      table.insert(ft_items, item)
+      -- While we're at it, also populate completion items for this request
       table.insert(items, utils.shallow_copy(item))
     end
 
+    self.items_cache[ft] = ft_items
+
     ::continue::
   end
 
   -- Filter items based on show_condition, if configured
-  if self.config.use_show_condition then
+  if self.opts.use_show_condition then
     local line_to_cursor = ctx.line:sub(0, ctx.cursor[2] - 1)
     items = vim.tbl_filter(function(item) return item.data.show_condition(line_to_cursor) end, items)
   end
@@ -137,15 +225,15 @@ function source:get_completions(ctx, callback)
     is_incomplete_forward = false,
     is_incomplete_backward = false,
     items = items,
-    context = ctx,
   })
 end
 
 function source:resolve(item, callback)
-  local snip = require('luasnip').get_id_snippet(item.data.snip_id)
+  local snip = luasnip.get_id_snippet(item.data.snip_id)
 
   local resolved_item = vim.deepcopy(item)
 
+  ---@type string|string[]|nil
   local detail = snip:get_docstring()
   if type(detail) == 'table' then detail = table.concat(detail, '\n') end
   resolved_item.detail = detail
@@ -160,35 +248,31 @@ function source:resolve(item, callback)
   callback(resolved_item)
 end
 
+---@param ctx blink.cmp.Context
+---@param item blink.cmp.CompletionItem
 function source:execute(ctx, item)
-  local luasnip = require('luasnip')
+  if item.data.choice_index then
+    luasnip.set_choice(item.data.choice_index)
+    return
+  end
+
   local snip = luasnip.get_id_snippet(item.data.snip_id)
 
-  -- if trigger is a pattern, expand "pattern" instead of actual snippet
+  local events = require('luasnip.util.events')
   if snip.regTrig then
-    local docTrig = self.config.prefer_doc_trig and snip.docTrig
+    local docTrig = self.opts.prefer_doc_trig and snip.docTrig
     snip = snip:get_pattern_expand_helper()
-
-    if docTrig then
-      add_luasnip_callback(snip, 'pre_expand', function(snip, _)
-        if #snip.insert_nodes == 0 then
-          snip.insert_nodes[0].static_text = { docTrig }
-        else
-          local matches = { string.match(docTrig, snip.trigger) }
-          for i, match in ipairs(matches) do
-            local idx = i ~= #matches and i or 0
-            snip.insert_nodes[idx].static_text = { match }
-          end
-        end
-      end)
-    end
+    if docTrig then add_luasnip_callback(snip, events.pre_expand, function(s) regex_callback(s, docTrig) end) end
+  else
+    add_luasnip_callback(snip, events.pre_expand, function(s) choice_callback(s, events) end)
   end
 
-  -- get (0, 0) indexed cursor position
-  local cursor = ctx.get_cursor()
+  local cursor = ctx.get_cursor() --[[@as LuaSnip.BytecolBufferPosition]]
   cursor[1] = cursor[1] - 1
 
-  local range = require('blink.cmp.lib.text_edits').get_from_item(item).range
+  local range = text_edits.get_from_item(item).range
+
+  ---@type LuaSnip.BufferRegion
   local clear_region = {
     from = { range.start.line, range.start.character },
     to = cursor,
@@ -199,17 +283,15 @@ function source:execute(ctx, item)
   local range_text = line:sub(range.start.character + 1, cursor[2])
 
   local expand_params = snip:matches(line_to_cursor, {
-    fallback_match = range_text ~= line_to_cursor and range_text,
+    fallback_match = range_text ~= line_to_cursor and range_text or nil,
   })
 
   if expand_params ~= nil then
     if expand_params.clear_region ~= nil then
       clear_region = expand_params.clear_region
     elseif expand_params.trigger ~= nil then
-      clear_region = {
-        from = { cursor[1], cursor[2] - #expand_params.trigger },
-        to = cursor,
-      }
+      clear_region.from = { cursor[1], cursor[2] - #expand_params.trigger }
+      clear_region.to = cursor
     end
   end