ruby/test/ripper/test_lexer.rb

# frozen_string_literal: true
begin
  require 'ripper'
  require 'test/unit'
  module TestRipper; end
rescue LoadError
end

class TestRipper::Lexer < Test::Unit::TestCase
  def test_nested_dedent_heredoc
    bug = '[ruby-core:80977] [Bug #13536]'
    str = <<~'E'
    <<~"D"
    #{
    <<~"B"
    this must be a valid ruby
    B
    }
    D
    E
    assert_equal(str, Ripper.tokenize(str).join(""), bug)

    str = <<~'E'
    <<~"D"
    #{
    <<~"B"
      this must be a valid ruby
    B
    }
    D
    E
    assert_equal(str, Ripper.tokenize(str).join(""), bug)
  end

  def test_embedded_expr_in_heredoc
    src = <<~'E'
    <<~B
      #{1}
    B
    E
    expect = %I[
      on_heredoc_beg
      on_nl
      on_ignored_sp
      on_embexpr_beg
      on_int
      on_embexpr_end
      on_tstring_content
      on_heredoc_end
    ]
    assert_equal expect, Ripper.lex(src).map {|e| e[1]}
  end

  def test_space_after_expr_in_heredoc
    src = <<~'E'
    <<~B
     #{1} a
    B
    E
    expect = %I[
      on_heredoc_beg
      on_nl
      on_ignored_sp
      on_embexpr_beg
      on_int
      on_embexpr_end
      on_tstring_content
      on_heredoc_end
    ]
    assert_equal expect, Ripper.lex(src).map {|e| e[1]}
  end

  def test_expr_at_beginning_in_heredoc
    src = <<~'E'
    <<~B
      a
    #{1}
    B
    E
    expect = %I[
      on_heredoc_beg
      on_nl
      on_tstring_content
      on_embexpr_beg
      on_int
      on_embexpr_end
      on_tstring_content
      on_heredoc_end
    ]
    assert_equal expect, Ripper.lex(src).map {|e| e[1]}
  end

  def test_stack_at_on_heredoc_beg
    src = "a <<b"
    expect = %I[
      on_ident
      on_sp
      on_heredoc_beg
    ]
    assert_equal expect, Ripper.lex(src).map {|e| e[1]}
  end

  def test_slice
    assert_equal "string\#{nil}\n",
      Ripper.slice(%(<<HERE\nstring\#{nil}\nHERE), "heredoc_beg .*? nl $(.*?) heredoc_end", 1)
  end

  def state(name)
    Ripper::Lexer::State.new(Ripper.const_get(name))
  end

  def test_state_after_ivar
    assert_equal [[1,0],:on_ivar,"@a",state(:EXPR_END)], Ripper.lex("@a").last
    assert_equal [[1,1],:on_ivar,"@a",state(:EXPR_ENDFN)], Ripper.lex(":@a").last
    assert_equal [[1,1],:on_int,"1",state(:EXPR_END)], Ripper.lex("@1").last
    assert_equal [[1,2],:on_int,"1",state(:EXPR_END)], Ripper.lex(":@1").last
  end

  def test_state_after_cvar
    assert_equal [[1,0],:on_cvar,"@@a",state(:EXPR_END)], Ripper.lex("@@a").last
    assert_equal [[1,1],:on_cvar,"@@a",state(:EXPR_ENDFN)], Ripper.lex(":@@a").last
    assert_equal [[1,2],:on_int,"1",state(:EXPR_END)], Ripper.lex("@@1").last
    assert_equal [[1,3],:on_int,"1",state(:EXPR_END)], Ripper.lex(":@@1").last
  end

  def test_token_aftr_error_heredoc
    code = "<<A.upcase\n"
    result = Ripper::Lexer.new(code).scan
    message = proc {result.pretty_inspect}
    expected = [
      [[1, 0], :on_heredoc_beg, "<<A", state(:EXPR_BEG)],
      [[1, 2], :compile_error, "A", state(:EXPR_BEG), "can't find string \"A\" anywhere before EOF"],
      [[1, 3], :on_period, ".", state(:EXPR_DOT)],
      [[1, 4], :on_ident, "upcase", state(:EXPR_ARG)],
      [[1, 10], :on_nl, "\n", state(:EXPR_BEG)],
    ]
    pos = 0
    expected.each_with_index do |ex, i|
      s = result[i]
      assert_equal ex, s.to_a, message
      if pos > s.pos[1]
        assert_equal pos, s.pos[1] + s.tok.bytesize, message
      else
        assert_equal pos, s.pos[1], message
        pos += s.tok.bytesize
      end
    end
    assert_equal pos, code.bytesize
    assert_equal expected.size, result.size
  end

  def test_trailing_on_embexpr_end
    # This is useful for scanning a template engine literal `{ foo, bar: baz }`
    # whose body inside brackes works like trailing method arguments, like Haml.
    token = Ripper.lex("a( foo, bar: baz }").last
    assert_equal [[1, 17], :on_embexpr_end, "}", state(:EXPR_ARG)], token
  end

  BAD_CODE = [
    [:parse_error,      'def req(true) end',         %r[unexpected `true'],         'true'],
    [:parse_error,      'def req(a, a) end',         %r[duplicated argument name],  'a'],
    [:assign_error,     'begin; nil = 1; end',       %r[assign to nil],             'nil'],
    [:alias_error,      'begin; alias $x $1; end',   %r[number variables],          '$1'],
    [:class_name_error, 'class bad; end',            %r[class/module name],         'bad'],
    [:param_error,      'def req(@a) end',           %r[formal argument.*instance], '@a'],
    [:param_error,      'def req(a?:) end',          %r[formal argument must.*local], 'a?'],
  ]

  def test_raise_errors_keyword
    all_assertions do |all|
      BAD_CODE.each do |(err, code, message)|
        all.for([err, code]) do
          assert_raise_with_message(SyntaxError, message) { Ripper.tokenize(code, raise_errors: true) }
        end
      end
    end
  end

  def test_tokenize_with_syntax_error
    all_assertions do |all|
      BAD_CODE.each do |(err, code)|
        all.for([err, code]) do
          assert_equal "end", Ripper.tokenize(code).last
        end
      end
    end
  end

  def test_lex_with_syntax_error
    all_assertions do |all|
      BAD_CODE.each do |(err, code)|
        all.for([err, code]) do
          assert_equal [[1, code.size-3], :on_kw, "end", state(:EXPR_END)], Ripper.lex(code).last
        end
      end
    end
  end

  def test_lexer_scan_with_syntax_error
    all_assertions do |all|
      BAD_CODE.each do |(err, code, message, token)|
        all.for([err, code]) do
          lexer = Ripper::Lexer.new(code)
          elems = lexer.scan
          assert_predicate lexer, :error?
          error = lexer.errors.first
          assert_match message, error.message
          i = elems.find_index{|e| e == error}
          assert_operator 0...elems.size, :include?, i
          elem = elems[i + 1]
          assert_not_equal error.event, elem.event
          assert_equal error.pos, elem.pos
          assert_equal error.tok, elem.tok
          assert_equal error.state, elem.state
        end
      end
    end
  end
end