Add textDocument/formatting implementation

This is tested with the Rust language server and the Lua one. Moving
the cursor to the correct position afterwards works with Rust, but not
with Lua. Being smarter about the ranges is probably necessary for Lua
and might make other ones more robust.

1 files changed, 53 insertions, 0 deletions

diff --git a/init.lua b/init.lua
index 9f3e7d4..48f7b97 100644
--- a/init.lua
+++ b/init.lua
@@ -365,6 +365,27 @@ local function vis_apply_textEdit(win, file, textEdit)
   win:draw()
 end
 
+-- apply a list of textEdits received from the language server
+local function vis_apply_textEdits(win, file, textEdits)
+  assert(win.file == file)
+
+  local edits = {}
+  for _, textEdit in ipairs(textEdits) do
+    local range = lsp_range_to_vis_range(win, textEdit.range)
+    table.insert(edits, {
+      mark = file:mark_set(range.start),
+      len = range.finish - range.start,
+      newText = textEdit.newText,
+    })
+  end
+  for _, edit in ipairs(edits) do
+    local pos = file:mark_get(edit.mark)
+    file:delete(pos, edit.len)
+    file:insert(pos, edit.newText)
+  end
+  win:draw()
+end
+
 -- concatenate all numeric values in choices and pass it on stdin to lspc.menu_cmd
 local function lspc_select(choices)
   local menu_input = ''
@@ -782,6 +803,10 @@ local function lspc_handle_rename_method_response(win, result)
   vis_apply_workspaceEdit(win, win.file, result)
 end
 
+local function lspc_handle_formatting_method_response(win, result)
+  vis_apply_textEdits(win, win.file, result)
+end
+
 local function lspc_handle_initialize_response(ls, result)
   ls.initialized = true
   ls.capabilities = result.capabilities
@@ -841,6 +866,9 @@ local function ls_handle_method_response(ls, method_response, req)
   elseif method == 'textDocument/rename' then
     lspc_handle_rename_method_response(win, result)
 
+  elseif method == 'textDocument/formatting' then
+    lspc_handle_formatting_method_response(win, result)
+
   elseif method == 'shutdown' then
     ls_send_notification(ls, 'exit')
     ls.fd:close()
@@ -1298,6 +1326,31 @@ vis:command_register('lspc-rename', function(argv, _, win)
   ls_call_text_document_method(ls, 'rename', params, win)
 end)
 
+vis:command_register('lspc-format', function(_, _, win)
+  local ls, err = lspc_get_usable_ls(win.syntax)
+  if err then
+    lspc_err(err)
+    return
+  end
+
+  -- check if the language server has a provider for this method
+  if not ls.capabilities['documentFormattingProvider'] then
+    lspc_err('language server ' .. ls.name .. ' does not provide formatting')
+    return
+  end
+
+  if not ls.open_files[win.file.path] then
+    lspc_open(ls, win, win.file)
+  end
+
+  local params = {
+    textDocument = {uri = path_to_uri(win.file.path)},
+    options = {tabSize = 2, insertSpaces = true},
+  }
+
+  ls_call_text_document_method(ls, 'formatting', params, win)
+end)
+
 vis:command_register('lspc-completion', function(_, _, win)
   local ls, err = lspc_get_usable_ls(win.syntax)
   if err then