text: require_relative '../spec_helper'
  require_relative 'fixtures/classes'
  
  describe "Literal Regexps" do
    it "matches against $_ (last input) in a conditional if no explicit matchee provided" do
      -> {
        eval <<-EOR
        $_ = nil
        (true if /foo/).should_not == true
  
        $_ = "foo"
        (true if /foo/).should == true
        EOR
      }.should complain(/regex literal in condition/)
    end
  
    it "yields a Regexp" do
      /Hello/.should be_kind_of(Regexp)
    end
  
    ruby_version_is "2.8" do
      it "is frozen" do
        /Hello/.should.frozen?
      end
    end
  
    it "caches the Regexp object" do
      rs = []
      2.times do |i|
        rs << /foo/
      end
      rs[0].should equal(rs[1])
    end
  
    it "throws SyntaxError for malformed literals" do
      -> { eval('/(/') }.should raise_error(SyntaxError)
    end
  
    #############################################################################
    # %r
    #############################################################################
  
    it "supports paired delimiters with %r" do
      LanguageSpecs.paired_delimiters.each do |p0, p1|
        eval("%r#{p0} foo #{p1}").should == / foo /
      end
    end
  
    it "supports grouping constructs that are also paired delimiters" do
      LanguageSpecs.paired_delimiters.each do |p0, p1|
        eval("%r#{p0} () [c]{1} #{p1}").should == / () [c]{1} /
      end
    end
  
    it "allows second part of paired delimiters to be used as non-paired delimiters" do
      LanguageSpecs.paired_delimiters.each do |p0, p1|
        eval("%r#{p1} foo #{p1}").should == / foo /
      end
    end
  
    it "disallows first part of paired delimiters to be used as non-paired delimiters" do
      LanguageSpecs.paired_delimiters.each do |p0, p1|
        -> { eval("%r#{p0} foo #{p0}") }.should raise_error(SyntaxError)
      end
    end
  
    it "supports non-paired delimiters delimiters with %r" do
      LanguageSpecs.non_paired_delimiters.each do |c|
        eval("%r#{c} foo #{c}").should == / foo /
      end
    end
  
    it "disallows alphabets as non-paired delimiter with %r" do
      -> { eval('%ra foo a') }.should raise_error(SyntaxError)
    end
  
    it "disallows spaces after %r and delimiter" do
      -> { eval('%r !foo!') }.should raise_error(SyntaxError)
    end
  
    it "allows unescaped / to be used with %r" do
      %r[/].to_s.should == /\//.to_s
    end
  
  
    #############################################################################
    # Specs for the matching semantics
    #############################################################################
  
    it "supports . (any character except line terminator)" do
      # Basic matching
      /./.match("foo").to_a.should == ["f"]
      # Basic non-matching
      /./.match("").should be_nil
      /./.match("\n").should be_nil
      /./.match("\0").to_a.should == ["\0"]
    end
  
  
    it "supports | (alternations)" do
      /a|b/.match("a").to_a.should == ["a"]
    end
  
    it "supports (?> ) (embedded subexpression)" do
      /(?>foo)(?>bar)/.match("foobar").to_a.should == ["foobar"]
      /(?>foo*)obar/.match("foooooooobar").should be_nil # it is possessive
    end
  
    it "supports (?# )" do
      /foo(?#comment)bar/.match("foobar").to_a.should == ["foobar"]
      /foo(?#)bar/.match("foobar").to_a.should == ["foobar"]
    end
  
    it "supports (?<= ) (positive lookbehind)" do
      /foo.(?<=\d)/.match("fooA foo1").to_a.should == ["foo1"]
    end
  
    # https://bugs.ruby-lang.org/issues/13671
    it "raises a RegexpError for lookbehind with specific characters" do
      r =  Regexp.new("(?<!dss)", Regexp::IGNORECASE)
      -> { r =~ "✨" }.should raise_error(RegexpError)
    end
  
    it "supports (?<! ) (negative lookbehind)" do
      /foo.(?<!\d)/.match("foo1 fooA").to_a.should == ["fooA"]
    end
  
    it "supports \\g (named backreference)" do
      /(?<foo>foo.)bar\g<foo>/.match("foo1barfoo2").to_a.should == ["foo1barfoo2", "foo2"]
    end
  
    it "supports character class composition" do
      /[a-z&&[^a-c]]+/.match("abcdef").to_a.should == ["def"]
      /[a-z&&[^d-i&&[^d-f]]]+/.match("abcdefghi").to_a.should == ["abcdef"]
    end
  
    it "supports possessive quantifiers" do
      /fooA++bar/.match("fooAAAbar").to_a.should == ["fooAAAbar"]
  
      /fooA++Abar/.match("fooAAAbar").should be_nil
      /fooA?+Abar/.match("fooAAAbar").should be_nil
      /fooA*+Abar/.match("fooAAAbar").should be_nil
    end
  
    it "supports conditional regular expressions with positional capture groups" do
      pattern = /\A(foo)?(?(1)(T)|(F))\z/
  
      pattern.should =~ 'fooT'
      pattern.should =~ 'F'
      pattern.should_not =~ 'fooF'
      pattern.should_not =~ 'T'
    end
  
    it "supports conditional regular expressions with named capture groups" do
      pattern = /\A(?<word>foo)?(?(<word>)(T)|(F))\z/
  
      pattern.should =~ 'fooT'
      pattern.should =~ 'F'
      pattern.should_not =~ 'fooF'
      pattern.should_not =~ 'T'
    end
  
    escapable_terminators =  ['!', '"', '#', '%', '&', "'", ',', '-', ':', ';', '@', '_', '`']
  
    it "supports escaping characters when used as a terminator" do
      escapable_terminators.each do |c|
        ref = "(?-mix:#{c})"
        pattern = eval("%r" + c + "\\" + c + c)
        pattern.to_s.should == ref
      end
    end
  
    it "treats an escaped non-escapable character normally when used as a terminator" do
      all_terminators = [*("!".."/"), *(":".."@"), *("[".."`"), *("{".."~")]
      special_cases = ['(', '{', '[', '<', '\\', '=', '~']
      (all_terminators - special_cases - escapable_terminators).each do |c|
        ref = "(?-mix:\\#{c})"
        pattern = eval("%r" + c + "\\" + c + c)
        pattern.to_s.should == ref
      end
    end
  
    it "support handling unicode 9.0 characters with POSIX bracket expressions" do
      char_lowercase = "\u{104D8}" # OSAGE SMALL LETTER A
      /[[:lower:]]/.match(char_lowercase).to_s.should == char_lowercase
      char_uppercase = "\u{104B0}" # OSAGE CAPITAL LETTER A
      /[[:upper:]]/.match(char_uppercase).to_s.should == char_uppercase
    end
  end
  