# frozen_string_literal: true
require "active_support/test_case"
require "prism"
require "ripper"
require "benchmark/ips"
class PrismParser
  def self.definition_for(method)
    filepath, start_line = method.source_location
    queue = [Prism.parse_file(filepath).value]
    while (node = queue.shift)
      case node.type
      when :def_node
        if node.name.start_with?("test") && node.location.start_line == start_line
          return [filepath, start_line..node.location.end_line]
        end
      when :call_node
        if node.name == :test && node.location.start_line == start_line
          return [filepath, start_line..node.location.end_line]
        end
      end
      queue.concat(node.compact_child_nodes)
    end
    nil
  end
end
class RipperParser < Ripper
  def self.definition_for(method_obj)
    path, begin_line = method_obj.source_location
    begins_to_ends = new(File.read(path), path).parse
    return unless end_line = begins_to_ends[begin_line]
    [path, (begin_line..end_line)]
  end
  def initialize(*)
    # A hash mapping the 1-indexed line numbers that tests start on to where they end.
    @begins_to_ends = {}
    super
  end
  def parse
    super
    @begins_to_ends
  end
  def on_def(begin_line, *)
    @begins_to_ends[begin_line] = lineno
  end
  def on_method_add_block(begin_line, end_line)
    if begin_line && end_line
      @begins_to_ends[begin_line] = end_line
    end
  end
  def on_command_call(*, begin_lineno, _args)
    begin_lineno
  end
  def first_arg(arg, *)
    arg
  end
  def just_lineno(*)
    lineno
  end
  alias on_method_add_arg first_arg
  alias on_command first_arg
  alias on_stmts_add first_arg
  alias on_arg_paren first_arg
  alias on_bodystmt first_arg
  alias on_ident just_lineno
  alias on_do_block just_lineno
  alias on_stmts_new just_lineno
  alias on_brace_block just_lineno
  def on_args_new
    []
  end
  def on_args_add(parts, part)
    parts << part
  end
  def on_args_add_block(args, *rest)
    args.first
  end
end
class ExampleTest < ActiveSupport::TestCase
  def test_method
    assert true
  end
  def test_oneline; assert true; end
  test "declarative" do
    assert true
  end
  test("declarative w/parens") do
    assert true
  end
  self.test "declarative explicit receiver" do
    assert true
  end
  test("declarative oneline") { assert true }
  test("declarative oneline do") do assert true end
  test("declarative multiline w/ braces") {
    assert true
    refute false
  }
end
methods = ExampleTest.instance_methods.grep(/^test_/).map { |method| ExampleTest.instance_method(method) }
Benchmark.ips do |x|
  x.report("Prism") { methods.each { |method| PrismParser.definition_for(method) } }
  x.report("Ripper") { methods.each { |method| RipperParser.definition_for(method) } }
  x.compare!
end