Stop empty lines setting indentation to zero (#32)

* Added check for empty lines when deciding indent level

* Fixed end

* Try with '' line check

* changed check for l:match("^%s*$")

* fixed regex check

* line -> v

* changed goto -> if ... then block

Co-authored-by: Paegodu <pablo@desktop.localdomain>

lua/nvim_comment.lua

@@ -92,9 +92,11 @@ function M.comment_toggle(line_start, line_end)
     end
     -- TODO what if already commented line has smallest indent?
     -- TODO no tests for this indent block
-    local line_indent = v:match("^%s+") or ""
-    if not indent or string.len(line_indent) < string.len(indent) then
-      indent = line_indent
+    if not v:match("^%s*$") then
+      local line_indent = v:match("^%s+") or ""
+      if not indent or string.len(line_indent) < string.len(indent) then
+        indent = line_indent
+      end
     end
   end