1 files changed, 63 insertions, 0 deletions
diff --git a/spec/ruby/language/regexp/grouping_spec.rb b/spec/ruby/language/regexp/grouping_spec.rb
new file mode 100644
index 0000000000..80ad7460da
--- /dev/null
+++ b/spec/ruby/language/regexp/grouping_spec.rb
@@ -0,0 +1,63 @@
+require_relative '../../spec_helper'
+require_relative '../fixtures/classes'
+
+describe "Regexps with grouping" do
+  it "support ()" do
+    /(a)/.match("a").to_a.should == ["a", "a"]
+  end
+
+  it "allows groups to be nested" do
+    md = /(hay(st)a)ck/.match('haystack')
+    md.to_a.should == ['haystack','haysta', 'st']
+  end
+
+  it "raises a SyntaxError when parentheses aren't balanced" do
+    -> { eval "/(hay(st)ack/" }.should.raise(SyntaxError)
+  end
+
+  it "supports (?: ) (non-capturing group)" do
+    /(?:foo)(bar)/.match("foobar").to_a.should == ["foobar", "bar"]
+    # Parsing precedence
+    /(?:xdigit:)/.match("xdigit:").to_a.should == ["xdigit:"]
+  end
+
+  it "group names cannot start with digits or minus" do
+    -> { Regexp.new("(?<1a>a)") }.should.raise(RegexpError)
+    -> { Regexp.new("(?<-a>a)") }.should.raise(RegexpError)
+  end
+
+  it "ignore capture groups in line comments" do
+    /^
+     (a) # there is a capture group on this line
+     b   # there is no capture group on this line (not even here)
+     $/x.match("ab").to_a.should == [ "ab", "a" ]
+  end
+
+  it "does not consider # inside a character class as a comment" do
+    # From https://github.com/rubocop/rubocop/blob/39fcf1c568/lib/rubocop/cop/utils/format_string.rb#L18
+    regexp = /
+        % (?<type>%) # line comment
+      | % (?<flags>(?-mix:[ #0+-]|(?-mix:(\d+)\$))*) (?#group comment)
+        (?:
+          (?: (?-mix:(?<width>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))? (?-mix:\.(?<precision>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))? (?-mix:<(?<name>\w+)>)?
+            | (?-mix:(?<width>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))? (?-mix:<(?<name>\w+)>) (?-mix:\.(?<precision>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))?
+            | (?-mix:<(?<name>\w+)>) (?<more_flags>(?-mix:[ #0+-]|(?-mix:(\d+)\$))*) (?-mix:(?<width>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))? (?-mix:\.(?<precision>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))?
+          ) (?-mix:(?<type>[bBdiouxXeEfgGaAcps]))
+          | (?-mix:(?<width>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))? (?-mix:\.(?<precision>(?-mix:\d+|(?-mix:\*(?-mix:(\d+)\$)?))))? (?-mix:\{(?<name>\w+)\})
+        )
+    /x
+    regexp.named_captures.should == {
+      "type" => [1, 13],
+      "flags" => [2],
+      "width" => [3, 6, 11, 14],
+      "precision" => [4, 8, 12, 15],
+      "name" => [5, 7, 9, 16],
+      "more_flags" => [10]
+    }
+    match = regexp.match("%6.3f")
+    match[:width].should == '6'
+    match[:precision].should == '3'
+    match[:type].should == 'f'
+    match.to_a.should == [ "%6.3f", nil, "", "6", "3"] + [nil] * 8 + ["f"] + [nil] * 3
+  end
+end