fix(lsp): use line start/end for visual line selection (#22632)

Fixes https://github.com/neovim/neovim/issues/22629

runtime/lua/vim/lsp/buf.lua

@@ -118,8 +118,10 @@ function M.completion(context)
 end
 
 ---@private
+---@param bufnr integer
+---@param mode "v"|"V"
 ---@return table {start={row, col}, end={row, col}} using (1, 0) indexing
-local function range_from_selection()
+local function range_from_selection(bufnr, mode)
   -- TODO: Use `vim.region()` instead https://github.com/neovim/neovim/pull/13896
 
   -- [bufnum, lnum, col, off]; both row and column 1-indexed
@@ -138,6 +140,11 @@ local function range_from_selection()
     start_row, end_row = end_row, start_row
     start_col, end_col = end_col, start_col
   end
+  if mode == 'V' then
+    start_col = 1
+    local lines = api.nvim_buf_get_lines(bufnr, end_row - 1, end_row, true)
+    end_col = #lines[1]
+  end
   return {
     ['start'] = { start_row, start_col - 1 },
     ['end'] = { end_row, end_col - 1 },
@@ -200,7 +207,7 @@ function M.format(options)
   local mode = api.nvim_get_mode().mode
   local range = options.range
   if not range and mode == 'v' or mode == 'V' then
-    range = range_from_selection()
+    range = range_from_selection(bufnr, mode)
   end
   local method = range and 'textDocument/rangeFormatting' or 'textDocument/formatting'
 
@@ -772,7 +779,7 @@ function M.code_action(options)
     local end_ = assert(options.range['end'], 'range must have a `end` property')
     params = util.make_given_range_params(start, end_)
   elseif mode == 'v' or mode == 'V' then
-    local range = range_from_selection()
+    local range = range_from_selection(0, mode)
     params = util.make_given_range_params(range.start, range['end'])
   else
     params = util.make_range_params()

test/functional/plugin/lsp_spec.lua

@@ -3554,6 +3554,7 @@ describe('LSP', function()
         vim.cmd.normal('v')
         vim.api.nvim_win_set_cursor(0, { 2, 3 })
         vim.lsp.buf.format({ bufnr = bufnr, false })
+        vim.lsp.stop_client(client_id)
         return server.messages
       ]])
       eq("textDocument/rangeFormatting", result[3].method)
@@ -3563,6 +3564,52 @@ describe('LSP', function()
       }
       eq(expected_range, result[3].params.range)
     end)
+    it('format formats range in visual line mode', function()
+      exec_lua(create_server_definition)
+      local result = exec_lua([[
+        local server = _create_server({ capabilities = {
+          documentFormattingProvider = true,
+          documentRangeFormattingProvider = true,
+        }})
+        local bufnr = vim.api.nvim_get_current_buf()
+        local client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
+        vim.api.nvim_win_set_buf(0, bufnr)
+        vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, {'foo', 'bar baz'})
+        vim.api.nvim_win_set_cursor(0, { 1, 2 })
+        vim.cmd.normal('V')
+        vim.api.nvim_win_set_cursor(0, { 2, 1 })
+        vim.lsp.buf.format({ bufnr = bufnr, false })
+
+        -- Format again with visual lines going from bottom to top
+        -- Must result in same formatting
+        vim.cmd.normal("<ESC>")
+        vim.api.nvim_win_set_cursor(0, { 2, 1 })
+        vim.cmd.normal('V')
+        vim.api.nvim_win_set_cursor(0, { 1, 2 })
+        vim.lsp.buf.format({ bufnr = bufnr, false })
+
+        vim.lsp.stop_client(client_id)
+        return server.messages
+      ]])
+      local expected_methods = {
+        "initialize",
+        "initialized",
+        "textDocument/rangeFormatting",
+        "$/cancelRequest",
+        "textDocument/rangeFormatting",
+        "$/cancelRequest",
+        "shutdown",
+        "exit",
+      }
+      eq(expected_methods, vim.tbl_map(function(x) return x.method end, result))
+      -- uses first column of start line and last column of end line
+      local expected_range = {
+        start = { line = 0, character = 0 },
+        ['end'] = { line = 1, character = 7 },
+      }
+      eq(expected_range, result[3].params.range)
+      eq(expected_range, result[5].params.range)
+    end)
     it('Aborts with notify if no clients support requested method', function()
       exec_lua(create_server_definition)
       exec_lua([[