test_ruby_parser_tree_rewriter.rb

require('parser')

input = "function foo() {}"
buf = Parser::Source::Buffer.new("test", 1, source: input)
tr = Parser::Source::TreeRewriter::new(buf)

def range(buf, start_pos, end_pos)
  Parser::Source::Range::new(buf, start_pos, end_pos)
end

tr.insert_after(range(buf, 13, 13), "arg1")
tr.replace(range(buf, 1, 2), "12")
tr.replace(range(buf, 1, 2), "U")
tr.replace(range(buf, 2, 4), "34")
tr.remove(range(buf, 4, 5));


out = tr.process
puts out.inspect

# out: "fU34ion foo(arg1) {}"