fix(lsp): escape character inserted before } on code action (#338)

Author: mrcjkb

CHANGELOG.md

@@ -6,6 +6,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+
+- Escape character inserted before `}` when applying code action
+  with `SnippetTextEdit` [[#303](https://github.com/mrcjkb/rustaceanvim/issues/303)].
+
 ## [4.18.2] - 2024-03-28
 
 ### Changed

lua/rustaceanvim/overrides.lua

@@ -1,16 +1,34 @@
 local M = {}
 
+---@param input string unparsed snippet
+---@return string parsed snippet
+local function parse_snippet_fallback(input)
+  local output = input
+    -- $0 -> Nothing
+    :gsub('%$%d', '')
+    -- ${0:_} -> _
+    :gsub('%${%d:(.-)}', '%1')
+    :gsub([[\}]], '}')
+  return output
+end
+
+---@param input string unparsed snippet
+---@return string parsed snippet
+local function parse_snippet(input)
+  local ok, parsed = pcall(function()
+    return vim.lsp._snippet_grammar.parse(input)
+  end)
+  return ok and tostring(parsed) or parse_snippet_fallback(input)
+end
+
 ---@param spe? table
 function M.snippet_text_edits_to_text_edits(spe)
   if type(spe) ~= 'table' then
     return
   end
   for _, value in ipairs(spe) do
     if value.newText and value.insertTextFormat then
-      -- $0 -> Nothing
-      value.newText = string.gsub(value.newText, '%$%d', '')
-      -- ${0:_} -> _
-      value.newText = string.gsub(value.newText, '%${%d:(.-)}', '%1')
+      value.newText = parse_snippet(value.newText)
     end
   end
 end