feat: snippet completions for functions (#116)

.luacheckrc

@@ -2,6 +2,9 @@
 ignore = {
   "631", -- max_line_length
 }
+exclude_files = {
+  ".tests",
+}
 globals = { "vim", "P" }
 read_globals = {
   "describe",

README.md

@@ -138,6 +138,8 @@ require("typescript-tools").setup {
     -- described below
     tsserver_format_options = {},
     tsserver_file_preferences = {},
+    -- mirror of VSCode's `typescript.suggest.completeFunctionCalls`
+    complete_function_calls = false,
   },
 }
 ```

lua/typescript-tools/config.lua

@@ -8,10 +8,61 @@
 ---@field tsserver_format_options table|fun(filetype: string): table
 ---@field tsserver_file_preferences table|fun(filetype: string): table
 ---@field tsserver_max_memory number|"auto"
+---@field complete_function_calls boolean
 ---@field expose_as_code_action ("fix_all"| "add_missing_imports"| "remove_unused")[]
 local M = {}
 local __store = {}
 
+-- INFO: this two defaults are same as in vscode
+local default_format_options = {
+  insertSpaceAfterCommaDelimiter = true,
+  insertSpaceAfterConstructor = false,
+  insertSpaceAfterSemicolonInForStatements = true,
+  insertSpaceBeforeAndAfterBinaryOperators = true,
+  insertSpaceAfterKeywordsInControlFlowStatements = true,
+  insertSpaceAfterFunctionKeywordForAnonymousFunctions = true,
+  insertSpaceBeforeFunctionParenthesis = false,
+  insertSpaceAfterOpeningAndBeforeClosingNonemptyParenthesis = false,
+  insertSpaceAfterOpeningAndBeforeClosingNonemptyBrackets = false,
+  insertSpaceAfterOpeningAndBeforeClosingNonemptyBraces = true,
+  insertSpaceAfterOpeningAndBeforeClosingEmptyBraces = true,
+  insertSpaceAfterOpeningAndBeforeClosingTemplateStringBraces = false,
+  insertSpaceAfterOpeningAndBeforeClosingJsxExpressionBraces = false,
+  insertSpaceAfterTypeAssertion = false,
+  placeOpenBraceOnNewLineForFunctions = false,
+  placeOpenBraceOnNewLineForControlBlocks = false,
+  semicolons = "ignore",
+  indentSwitchCase = true,
+}
+
+local default_preferences = {
+  quotePreference = "auto",
+  importModuleSpecifierEnding = "auto",
+  jsxAttributeCompletionStyle = "auto",
+  allowTextChangesInNewFiles = true,
+  providePrefixAndSuffixTextForRename = true,
+  allowRenameOfImportPath = true,
+  includeAutomaticOptionalChainCompletions = true,
+  provideRefactorNotApplicableReason = true,
+  generateReturnInDocTemplate = true,
+  includeCompletionsForImportStatements = true,
+  includeCompletionsWithSnippetText = true,
+  includeCompletionsWithClassMemberSnippets = true,
+  includeCompletionsWithObjectLiteralMethodSnippets = true,
+  useLabelDetailsInCompletionEntries = true,
+  allowIncompleteCompletions = true,
+  displayPartsForJSDoc = true,
+  disableLineTextInReferences = true,
+  includeInlayParameterNameHints = "none",
+  includeInlayParameterNameHintsWhenArgumentMatchesName = false,
+  includeInlayFunctionParameterTypeHints = false,
+  includeInlayVariableTypeHints = false,
+  includeInlayVariableTypeHintsWhenTypeMatchesName = false,
+  includeInlayPropertyDeclarationTypeHints = false,
+  includeInlayFunctionLikeReturnTypeHints = false,
+  includeInlayEnumMemberValueHints = false,
+}
+
 ---@enum tsserver_log_level
 M.tsserver_log_level = {
   normal = "normal",
@@ -56,6 +107,7 @@ function M.load_settings(settings)
       { "number", "string" },
       true,
     },
+    ["settings.complete_function_calls"] = { settings.complete_function_calls, "boolean", true },
     ["settings.expose_as_code_action"] = {
       settings.expose_as_code_action,
       "table",
@@ -93,6 +145,10 @@ function M.load_settings(settings)
     __store.tsserver_max_memory = "auto"
   end
 
+  if not settings.complete_function_calls then
+    __store.complete_function_calls = false
+  end
+
   if not settings.expose_as_code_action then
     __store.expose_as_code_action = {}
   end
@@ -104,4 +160,17 @@ setmetatable(M, {
   end,
 })
 
+---@param filetype vim.opt.filetype
+---@return table
+function M.get_tsserver_file_preferences(filetype)
+  local preferences = __store.tsserver_file_preferences
+  return vim.tbl_extend(
+    "force",
+    default_preferences,
+    type(preferences) == "function" and preferences(filetype) or preferences
+  )
+end
+
+M.default_format_options = default_format_options
+
 return M

lua/typescript-tools/protocol/constants.lua

@@ -270,6 +270,7 @@ return {
     Imports = "imports",
     Region = "region",
   },
+  ---@enum InsertTextFormat
   InsertTextFormat = {
     PlainText = 1,
     Snippet = 2,

lua/typescript-tools/protocol/text_document/completion/init.lua

@@ -25,6 +25,8 @@ function M.handler(request, response, params)
   local text_document = params.textDocument
   local context = params.context or {}
   local trigger_character = context.triggerCharacter
+  local requested_bufnr = vim.uri_to_bufnr(text_document.uri)
+  local filetype = vim.bo[requested_bufnr].filetype
 
   -- tsserver protocol reference:
   -- https//github.com/microsoft/TypeScript/blob/8b482b513d87c6fcda8ece18b99f8a01cff5c605/lib/protocol.d.ts#L1631
@@ -65,14 +67,19 @@ function M.handler(request, response, params)
         sortText = "\u{ffff}" .. item.sortText
       end
 
+      local should_create_function_snippet = utils.should_create_function_snippet(kind, filetype)
+      local should_create_snippet = item.isSnippet or should_create_function_snippet
+      local label = is_optional and (item.name .. "?") or item.name
+      label = should_create_function_snippet and (label .. "(...)") or label
+
       return {
-        label = is_optional and (item.name .. "?") or item.name,
+        label = label,
         labelDetails = item.labelDetails,
         insertText = insertText,
         filterText = insertText,
         commitCharacters = item_kind_utils.calculate_commit_characters(kind),
         kind = kind,
-        insertTextFormat = item.isSnippet and c.InsertTextFormat.Snippet
+        insertTextFormat = should_create_snippet and c.InsertTextFormat.Snippet
           or c.InsertTextFormat.PlainText,
         sortText = sortText,
         textEdit = calculate_text_edit(item.replacementSpan, insertText),

lua/typescript-tools/protocol/text_document/completion/resolve.lua

@@ -26,6 +26,89 @@ local function make_text_edits(code_actions)
   return text_edits
 end
 
+---@alias DisplayPart { kind: string, text: string }
+
+---@param display_parts DisplayPart[]
+---@return { has_optional_parameters: boolean, parts: DisplayPart[] }
+---@see https://github.com/typescript-language-server/typescript-language-server/blob/983a6923114c39d638e0c7d419ae16e8bca8985c/src/completion.ts#L355-L371
+local function get_parameter_list_parts(display_parts)
+  local parts = {}
+  local is_in_method = false
+  local has_optional_parameters = false
+  local paren_count = 0
+  local brace_count = 0
+
+  for i, part in ipairs(display_parts) do
+    if
+      part.kind == "methodName"
+      or part.kind == "functionName"
+      or part.kind == "text"
+      or part.kind == "propertyName"
+    then
+      if paren_count == 0 and brace_count == 0 then
+        is_in_method = true
+      end
+    elseif part.kind == "parameterName" then
+      if paren_count == 1 and brace_count == 0 and is_in_method then
+        local next = display_parts[i + 1]
+        local name_is_followed_by_optional_indicator = next and next.text == "?"
+        local name_is_this = part.text == "this"
+        if not name_is_followed_by_optional_indicator and not name_is_this then
+          table.insert(parts, part)
+        end
+        has_optional_parameters = has_optional_parameters or name_is_followed_by_optional_indicator
+      end
+    elseif part.kind == "punctuation" then
+      if part.text == "(" then
+        paren_count = paren_count + 1
+      elseif part.text == ")" then
+        paren_count = paren_count - 1
+        if paren_count <= 0 and is_in_method then
+          break
+        end
+      elseif part.text == "..." and paren_count == 1 then
+        has_optional_parameters = true
+        break
+      elseif part.text == "{" then
+        brace_count = brace_count + 1
+      elseif part.text == "}" then
+        brace_count = brace_count - 1
+      end
+    end
+  end
+  return { has_optional_parameters = has_optional_parameters, parts = parts }
+end
+
+---@alias PartialCompletionItem
+---| { insertText: string, insertTextFormat: InsertTextFormat, textEdit: { newText: string }, label: string }
+
+---@param item PartialCompletionItem
+---@param display_parts DisplayPart[]
+---@return nil
+---@see https://github.com/typescript-language-server/typescript-language-server/blob/983a6923114c39d638e0c7d419ae16e8bca8985c/src/completion.ts#L355-L371
+local function create_snippet(item, display_parts)
+  local parameter_list_parts = get_parameter_list_parts(display_parts)
+  local has_optional_parameters = parameter_list_parts.has_optional_parameters
+  local parts = parameter_list_parts.parts
+  local snippet =
+    string.format("%s(", item.insertText or (item.textEdit and item.textEdit.newText) or item.label)
+  for i, part in ipairs(parts) do
+    snippet = snippet .. string.format("${%d:%s}", i, part.text:gsub("([$}\\])", "\\%1"))
+    if i ~= #parts then
+      snippet = snippet .. ", "
+    end
+  end
+  if has_optional_parameters then
+    snippet = snippet .. string.format("$%d", #parts + 1)
+  end
+  snippet = snippet .. ")$0"
+  item.insertText = snippet
+  item.insertTextFormat = c.InsertTextFormat.Snippet
+  if item.textEdit then
+    item.textEdit.newText = snippet
+  end
+end
+
 ---@param params table
 ---@return table
 local function completion_resolve_request(params)
@@ -50,6 +133,9 @@ end
 
 ---@type TsserverProtocolHandler
 function M.handler(request, response, params)
+  local requested_bufnr = vim.uri_to_bufnr(vim.uri_from_fname(params.data.file))
+  local filetype = vim.bo[requested_bufnr].filetype
+
   -- tsserver protocol reference:
   -- https://github.com/microsoft/TypeScript/blob/549e61d0af1ba885be29d69f341e7d3a00686071/lib/protocol.d.ts#L1661
   request(completion_resolve_request(params))
@@ -74,7 +160,7 @@ function M.handler(request, response, params)
       detail = "Auto import from " .. utils.tsserver_docs_to_plain_text(source) .. "\n" .. detail
     end
 
-    response(vim.tbl_extend("force", params, {
+    local item = vim.tbl_extend("force", params, {
       detail = detail,
       documentation = {
         kind = c.MarkupKind.Markdown,
@@ -83,7 +169,13 @@ function M.handler(request, response, params)
       additionalTextEdits = make_text_edits(details.codeActions),
       -- INFO: there is also `command` prop but I don't know there is usecase for that here,
       -- or neovim even handle that for now i skip this
-    }))
+    })
+
+    if utils.should_create_function_snippet(item.kind, filetype) then
+      create_snippet(item, details.displayParts)
+    end
+
+    response(item)
   else
     response(nil)
   end

lua/typescript-tools/protocol/text_document/did_open.lua

@@ -4,56 +4,6 @@ local plugin_config = require "typescript-tools.config"
 
 local M = {}
 
--- INFO: this two defaults are same as in vscode
-local default_format_options = {
-  insertSpaceAfterCommaDelimiter = true,
-  insertSpaceAfterConstructor = false,
-  insertSpaceAfterSemicolonInForStatements = true,
-  insertSpaceBeforeAndAfterBinaryOperators = true,
-  insertSpaceAfterKeywordsInControlFlowStatements = true,
-  insertSpaceAfterFunctionKeywordForAnonymousFunctions = true,
-  insertSpaceBeforeFunctionParenthesis = false,
-  insertSpaceAfterOpeningAndBeforeClosingNonemptyParenthesis = false,
-  insertSpaceAfterOpeningAndBeforeClosingNonemptyBrackets = false,
-  insertSpaceAfterOpeningAndBeforeClosingNonemptyBraces = true,
-  insertSpaceAfterOpeningAndBeforeClosingEmptyBraces = true,
-  insertSpaceAfterOpeningAndBeforeClosingTemplateStringBraces = false,
-  insertSpaceAfterOpeningAndBeforeClosingJsxExpressionBraces = false,
-  insertSpaceAfterTypeAssertion = false,
-  placeOpenBraceOnNewLineForFunctions = false,
-  placeOpenBraceOnNewLineForControlBlocks = false,
-  semicolons = "ignore",
-  indentSwitchCase = true,
-}
-
-local default_preferences = {
-  quotePreference = "auto",
-  importModuleSpecifierEnding = "auto",
-  jsxAttributeCompletionStyle = "auto",
-  allowTextChangesInNewFiles = true,
-  providePrefixAndSuffixTextForRename = true,
-  allowRenameOfImportPath = true,
-  includeAutomaticOptionalChainCompletions = true,
-  provideRefactorNotApplicableReason = true,
-  generateReturnInDocTemplate = true,
-  includeCompletionsForImportStatements = true,
-  includeCompletionsWithSnippetText = true,
-  includeCompletionsWithClassMemberSnippets = true,
-  includeCompletionsWithObjectLiteralMethodSnippets = true,
-  useLabelDetailsInCompletionEntries = true,
-  allowIncompleteCompletions = true,
-  displayPartsForJSDoc = true,
-  disableLineTextInReferences = true,
-  includeInlayParameterNameHints = "none",
-  includeInlayParameterNameHintsWhenArgumentMatchesName = false,
-  includeInlayFunctionParameterTypeHints = false,
-  includeInlayVariableTypeHints = false,
-  includeInlayVariableTypeHintsWhenTypeMatchesName = false,
-  includeInlayPropertyDeclarationTypeHints = false,
-  includeInlayFunctionLikeReturnTypeHints = false,
-  includeInlayEnumMemberValueHints = false,
-}
-
 ---@type table<"mac" | "unix" | "dos", string>
 local eol_chars = {
   mac = "\r",
@@ -78,7 +28,6 @@ local function configure(params)
   local convert_tabs_to_spaces = bo.expandtab or true
   local new_line_character = get_eol_chars(bo)
 
-  local preferences = plugin_config.tsserver_file_preferences
   local format_options = plugin_config.tsserver_format_options
 
   return {
@@ -93,14 +42,10 @@ local function configure(params)
           convertTabsToSpaces = convert_tabs_to_spaces,
           newLineCharacter = new_line_character,
         },
-        default_format_options,
+        plugin_config.default_format_options,
         type(format_options) == "function" and format_options(bo.filetype) or format_options
       ),
-      preferences = vim.tbl_extend(
-        "force",
-        default_preferences,
-        type(preferences) == "function" and preferences(bo.filetype) or preferences
-      ),
+      preferences = plugin_config.get_tsserver_file_preferences(bo.filetype),
     },
   }
 end

lua/typescript-tools/protocol/text_document/inlay_hint.lua

@@ -13,8 +13,7 @@ local inlay_hint_kind_map = {
 ---@param filetype string
 ---@return boolean
 local function are_inlay_hints_enabled(filetype)
-  local preferences = plugin_config.tsserver_file_preferences
-  preferences = type(preferences) == "function" and preferences(filetype) or preferences
+  local preferences = plugin_config.get_tsserver_file_preferences(filetype)
 
   if not preferences then
     return false

lua/typescript-tools/protocol/utils.lua

@@ -1,4 +1,5 @@
 local c = require "typescript-tools.protocol.constants"
+local plugin_config = require "typescript-tools.config"
 
 local M = {}
 
@@ -222,4 +223,15 @@ function M.cancelled_response(data)
   }
 end
 
+---@param kind CompletionItemKind
+---@param filetype vim.opt.filetype
+---@return boolean
+---@see https://github.com/typescript-language-server/typescript-language-server/blob/983a6923114c39d638e0c7d419ae16e8bca8985c/src/completion.ts#L355-L371
+function M.should_create_function_snippet(kind, filetype)
+  local preferences = plugin_config.get_tsserver_file_preferences(filetype)
+  return preferences.includeCompletionsWithSnippetText
+    and (kind == c.CompletionItemKind.Function or kind == c.CompletionItemKind.Method)
+    and plugin_config.complete_function_calls
+end
+
 return M