Add test for new grammars

Author: nurse

test/test_grammar.rb

@@ -0,0 +1,105 @@
+require 'test/unit'
+require 'racc/static'
+require 'tempfile'
+
+class TestGrammar < Test::Unit::TestCase
+  private def with_parser(rule)
+    parser = Racc::GrammarFileParser.new
+    result = parser.parse(<<"eom", "foo.y")
+class MyParser
+rule
+#{rule}
+end
+---- header
+require 'strscan'
+---- inner
+def parse(str)
+  @ss = StringScanner.new(str)
+  do_parse
+end
+def next_token
+  @ss.skip(/\\s+/)
+  token = @ss.scan(/\\S+/) and [token, token]
+end
+eom
+    states = Racc::States.new(result.grammar).nfa
+    params = result.params.dup
+    generator = Racc::ParserFileGenerator.new(states, params)
+    Tempfile.create(%w[y .tab.rb]) do |f|
+      generator.generate_parser_file(f.path)
+      require f.path
+      parser = MyParser.new
+      yield parser
+    end
+    Object.__send__(:remove_const, :MyParser)
+  end
+
+  def test_optional
+    with_parser("stmt: 'abc'?") do |parser|
+      assert_equal "abc", parser.parse("abc")
+      assert_equal nil, parser.parse("")
+    end
+  end
+
+  def test_many
+    with_parser("stmt: 'abc'*") do |parser|
+      assert_equal [], parser.parse("")
+      assert_equal ["abc"], parser.parse("abc")
+      assert_equal ["abc", "abc"], parser.parse("abc abc")
+      assert_equal ["abc", "abc", "abc"], parser.parse("abc abc abc")
+    end
+  end
+
+  def test_many1
+    with_parser("stmt: 'abc'+") do |parser|
+      assert_raise(Racc::ParseError){ parser.parse("") }
+      assert_equal ["abc"], parser.parse("abc")
+      assert_equal ["abc", "abc"], parser.parse("abc abc")
+      assert_equal ["abc", "abc", "abc"], parser.parse("abc abc abc")
+    end
+  end
+
+  def test_group
+    with_parser("stmt: ('a')") do |parser|
+      assert_raise(Racc::ParseError){ parser.parse("") }
+      assert_equal ["a"], parser.parse("a")
+    end
+
+    with_parser("stmt: ('a' 'b')") do |parser|
+      assert_raise(Racc::ParseError){ parser.parse("") }
+      assert_raise(Racc::ParseError){ parser.parse("a") }
+      assert_equal ["a", "b"], parser.parse("a b")
+    end
+  end
+
+  def test_group_or
+    with_parser("stmt: ('a' | 'b')") do |parser|
+      assert_raise(Racc::ParseError){ parser.parse("") }
+      assert_equal ["a"], parser.parse("a")
+      assert_equal ["b"], parser.parse("b")
+    end
+  end
+
+  def test_group_many
+    with_parser("stmt: ('a')*") do |parser|
+      assert_equal [], parser.parse("")
+      assert_equal [["a"]], parser.parse("a")
+      assert_equal [["a"], ["a"]], parser.parse("a a")
+    end
+
+    with_parser("start: stmt\n stmt: ('a' 'b')*") do |parser|
+      assert_equal [], parser.parse("")
+      assert_equal [["a", "b"]], parser.parse("a b")
+      assert_equal [["a", "b"], ["a", "b"]], parser.parse("a b a b")
+    end
+  end
+
+  def test_group_or_many
+    with_parser("stmt: ('a' | 'b')*") do |parser|
+      assert_equal [], parser.parse("")
+      assert_equal [["a"], ["a"]], parser.parse("a a")
+      assert_equal [["a"], ["b"]], parser.parse("a b")
+      assert_equal [["a"], ["b"], ["b"], ["a"]], parser.parse("a b b a")
+    end
+  end
+end