(mini.completion) Respect InsertReplaceText for LSP completion start.

Details:
- Resolves #708.

Author: echasnovski

lua/mini/completion.lua

@@ -1304,9 +1304,11 @@ H.get_completion_start_server = function(response_data, line_num)
   if response_data.err or type(response_data.result) ~= 'table' then return end
   local items = response_data.result.items or response_data.result
   for _, item in pairs(items) do
-    if type(item.textEdit) == 'table' and item.textEdit.range.start.line == line_num then
-      -- NOTE: Ignore case when items contain several conflicting starts
-      return item.textEdit.range.start.character
+    if type(item.textEdit) == 'table' then
+      -- NOTE: As per LSP spec, `textEdit` can be either `TextEdit` or `InsertReplaceEdit`
+      local range = type(item.textEdit.range) == 'table' and item.textEdit.range or item.textEdit.insert
+      -- NOTE: Return immediately, ignoring possibly several conflicting starts
+      return range.start.character
     end
   end
 end

tests/dir-completion/mock-months-lsp.lua

@@ -44,15 +44,18 @@ local construct_additionTextEdits = function(id, name)
   }
 end
 
-local construct_textEdit = function(name)
+local construct_textEdit = function(name, kind)
   if _G.mock_textEdit == nil then return end
   local new_text, pos = _G.mock_textEdit.new_text, _G.mock_textEdit.pos
+  local is_insertreplaceedit = kind == 'InsertReplaceEdit'
+  local range = {
+    start = { line = pos[1] - 1, character = pos[2] - 1 },
+    ['end'] = { line = pos[1] - 1, character = pos[2] },
+  }
   return {
     newText = new_text(name),
-    range = {
-      start = { line = pos[1] - 1, character = pos[2] - 1 },
-      ['end'] = { line = pos[1] - 1, character = pos[2] },
-    },
+    [is_insertreplaceedit and 'insert' or 'range'] = range,
+    replace = is_insertreplaceedit and range or nil,
   }
 end
 
@@ -71,8 +74,12 @@ Months.requests = {
         res.additionalTextEdits = construct_additionTextEdits('completion', item.name)
       end
 
-      if vim.tbl_contains({ 'April', 'August' }, item.name) then
-        res.textEdit = construct_textEdit(item.name)
+      if item.name == 'April' then
+        res.textEdit = construct_textEdit(item.name, 'InsertReplaceEdit')
+        res.filterText = construct_filterText(item.name)
+      end
+      if item.name == 'August' then
+        res.textEdit = construct_textEdit(item.name, 'textEdit')
         res.filterText = construct_filterText(item.name)
       end