fix: disallow line breaks in search/replace strings (#28)

README.md

@@ -223,7 +223,8 @@ regex more intuitive. However, if you regularly use named capture groups, you
 may want to disable this setting.
 
 ## Limitations
-- `--multiline` and various other flags are not supported yet.
+- Searching/replacing for line breaks (`\n` or `\r`) is not supported. [See
+  issue #28](https://github.com/chrisgrieser/nvim-rip-substitute/issues/28).
 - This plugin only searches the current buffer. To search and replace in
   multiple files via `ripgrep`, use a plugin like
   [grug-far.nvim](https://github.com/MagicDuck/grug-far.nvim).

lua/rip-substitute/rg-operations.lua

@@ -115,6 +115,11 @@ function M.incrementalPreviewAndMatchCount()
 
 	-- GUARD INVALID SEARCH/REPLACE STRINGS
 	if toSearch == "" then return end
+	if toSearch:find("[\n\r]") and toReplace:find("[\n\r]") then
+		-- see #28 or https://github.com/chrisgrieser/nvim-rip-substitute/issues/28#issuecomment-2503761241
+		u.notify("Search and replace strings cannot contain newlines.", "error")
+		return
+	end
 
 	-- DETERMINE MATCHES
 	local rgArgs = { "--line-number", "--column", "--only-matching", "--", toSearch }