2 files changed, 33 insertions, 10 deletions
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index 7a819f3c3d..81d78c8b98 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -65,19 +65,18 @@ function M.completion(context)
 end
 
 function M.formatting(options)
-  validate { options = {options, 't', true} }
-  local sts = vim.bo.softtabstop;
-  options = vim.tbl_extend('keep', options or {}, {
-    tabSize = (sts > 0 and sts) or (sts < 0 and vim.bo.shiftwidth) or vim.bo.tabstop;
-    insertSpaces = vim.bo.expandtab;
-  })
-  local params = {
-    textDocument = { uri = vim.uri_from_bufnr(0) };
-    options = options;
-  }
+  local params = util.make_formatting_params(options)
   return request('textDocument/formatting', params)
 end
 
+function M.formatting_sync(options, timeout_ms)
+  local params = util.make_formatting_params(options)
+  local result = vim.lsp.buf_request_sync(0, "textDocument/formatting", params, timeout_ms)
+  if not result then return end
+  result = result[1].result
+  vim.lsp.util.apply_text_edits(result)
+end
+
 function M.range_formatting(options, start_pos, end_pos)
   validate {
     options = {options, 't', true};
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 71ca1048e1..2b9b4d8c7e 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -1259,6 +1259,30 @@ function M.make_text_document_params()
   return { uri = vim.uri_from_bufnr(0) }
 end
 
+--- Get visual width of tabstop.
+---
+--@see |softtabstop|
+--@param bufnr (optional, number): Buffer handle, defaults to current
+--@returns (number) tabstop visual width
+function M.get_effective_tabstop(bufnr)
+  validate { bufnr = {bufnr, 'n', true} }
+  local bo = bufnr and vim.bo[bufnr] or vim.bo
+  local sts = bo.softtabstop
+  return (sts > 0 and sts) or (sts < 0 and bo.shiftwidth) or bo.tabstop
+end
+
+function M.make_formatting_params(options)
+  validate { options = {options, 't', true} }
+  options = vim.tbl_extend('keep', options or {}, {
+    tabSize = M.get_effective_tabstop();
+    insertSpaces = vim.bo.expandtab;
+  })
+  return {
+    textDocument = { uri = vim.uri_from_bufnr(0) };
+    options = options;
+  }
+end
+
 -- @param buf buffer handle or 0 for current.
 -- @param row 0-indexed line
 -- @param col 0-indexed byte offset in line