feat(lsp): apply additionalTextEdits on completion accept

lua/lsp/completion/init.lua

@@ -94,6 +94,79 @@ function M.setup()
         end,
     })
 
+    -- Apply the LSP item's additionalTextEdits (auto-imports, etc.) and
+    -- run its post-accept command whenever an item's text was committed to
+    -- the buffer. This covers both explicit accept (<C-y>) and
+    -- acceptance-by-continuing-to-type, since Vim keeps the inserted text
+    -- in both cases. Only <C-e>/discard leaves v:completed_item empty.
+    vim.api.nvim_create_autocmd("CompleteDone", {
+        group = GROUP,
+        callback = function(ev)
+            local completed = vim.v.completed_item or {}
+            local original = vim.tbl_get(
+                completed,
+                "user_data",
+                "nvim",
+                "lsp",
+                "completion_item"
+            )
+            if not original then
+                return
+            end
+            local client_id =
+                vim.tbl_get(completed, "user_data", "nvim", "lsp", "client_id")
+            local client = client_id and vim.lsp.get_client_by_id(client_id)
+            if not client then
+                return
+            end
+
+            local function apply(item)
+                if item.additionalTextEdits then
+                    vim.lsp.util.apply_text_edits(
+                        item.additionalTextEdits,
+                        ev.buf,
+                        client.offset_encoding
+                    )
+                end
+                if item.command then
+                    client:request("workspace/executeCommand", {
+                        command = item.command.command,
+                        arguments = item.command.arguments,
+                    }, nil, ev.buf)
+                end
+            end
+
+            -- Prefer the resolved item when we have it (servers like
+            -- rust-analyzer only provide additionalTextEdits in resolve
+            -- responses). If we haven't cached one yet and the original is
+            -- missing edits, resolve on the fly.
+            local cached = popup:resolved_for(completed.word)
+            if cached then
+                apply(cached)
+            elseif
+                client:supports_method(
+                    vim.lsp.protocol.Methods.completionItem_resolve
+                )
+                and not original.additionalTextEdits
+                and not original.command
+            then
+                client:request(
+                    vim.lsp.protocol.Methods.completionItem_resolve,
+                    original,
+                    function(err, resolved)
+                        if err or not resolved then
+                            return
+                        end
+                        apply(resolved)
+                    end,
+                    ev.buf
+                )
+            else
+                apply(original)
+            end
+        end,
+    })
+
     ---@param key string
     ---@param action fun()
     local function scroll_map(key, action)

lua/lsp/completion/popup.lua

@@ -22,42 +22,23 @@ local function fence(ft, text)
     return string.format("```%s\n%s\n```", ft, text)
 end
 
----@param item lsp.CompletionItem
----@return string
-local function signature_of(item)
-    return item.detail or vim.tbl_get(item, "labelDetails", "description") or ""
-end
-
 ---@param item lsp.CompletionItem
 ---@param ft string
 ---@return string? content
 ---@return integer? width
 local function build_content(item, ft)
-    local signature = signature_of(item)
+    local signature = item.detail
+        or vim.tbl_get(item, "labelDetails", "description")
     local doc = item.documentation
     if type(doc) == "table" then
         doc = doc.value
     end
-    doc = doc or ""
-
-    local code_parts = {}
-    if item.additionalTextEdits then
-        for _, edit in ipairs(item.additionalTextEdits) do
-            local text = (edit.newText or ""):gsub("%s+$", "")
-            if text ~= "" then
-                table.insert(code_parts, fence(ft, text))
-            end
-        end
-    end
-    if signature ~= "" then
-        table.insert(code_parts, fence(ft, signature))
-    end
 
     local sections = {}
-    if #code_parts > 0 then
-        table.insert(sections, table.concat(code_parts, "\n\n"))
+    if signature then
+        table.insert(sections, fence(ft, signature))
     end
-    if doc ~= "" then
+    if doc then
         table.insert(sections, doc)
     end
     if #sections == 0 then
@@ -78,6 +59,7 @@ end
 ---@field private winid integer?
 ---@field private bufnr integer?
 ---@field private pending ow.lsp.completion.PendingResolve?
+---@field private resolved { word: string, item: lsp.CompletionItem }?
 local Popup = {}
 Popup.__index = Popup
 
@@ -87,9 +69,23 @@ function Popup.new()
         winid = nil,
         bufnr = nil,
         pending = nil,
+        resolved = nil,
     }, Popup)
 end
 
+--- Most recently resolved completion item for the given selection `word`,
+--- or `nil` if we don't have one cached. Servers like rust-analyzer fill in
+--- `additionalTextEdits` only in the resolve response, so on accept we want
+--- the resolved version rather than the original one in `user_data`.
+---@param word string
+---@return lsp.CompletionItem?
+function Popup:resolved_for(word)
+    if self.resolved and self.resolved.word == word then
+        return self.resolved.item
+    end
+    return nil
+end
+
 ---@return boolean
 function Popup:is_visible()
     return self.winid ~= nil and vim.api.nvim_win_is_valid(self.winid)
@@ -127,6 +123,7 @@ end
 ---@param buf integer
 function Popup:dispatch_resolve(client, item, ft, pum, word, buf)
     self:cancel_pending()
+    self.resolved = nil
     local _, request_id = client:request(
         vim.lsp.protocol.Methods.completionItem_resolve,
         item,
@@ -139,6 +136,7 @@ function Popup:dispatch_resolve(client, item, ft, pum, word, buf)
             if (vim.tbl_get(cur, "completed", "word") or "") ~= word then
                 return
             end
+            self.resolved = { word = word, item = result }
             self:show(result, ft, pum)
         end,
         buf

lua/lsp/completion/request.lua

@@ -123,7 +123,7 @@ local function build_items(responses, base)
         result[#result + 1] = {
             word = item_word(item),
             abbr = item.label:match("[^(]+") or item.label,
-            menu = "",
+            menu = vim.tbl_get(item, "labelDetails", "detail") or "",
             kind = kind_icon,
             kind_hlgroup = kind_hl,
             -- non-empty so our CompleteChanged handler triggers resolve