Add specs for $~ in Enumerable#{grep,grep_v}

Author: eregon

spec/ruby/core/enumerable/grep_spec.rb

@@ -29,6 +29,28 @@ class EnumerableSpecGrep2; def ===(obj); /^ca/ =~ obj; end; end
     ary.grep(/a(b)a/) { $1 }.should == ["b", "b"]
   end
 
+  it "sets $~ in the block" do
+    "z" =~ /z/ # Reset $~
+    ["abc", "def"].grep(/b/) { |e|
+      e.should == "abc"
+      $&.should == "b"
+    }
+
+    # Set by the failed match of "def"
+    $~.should == nil
+  end
+
+  it "sets $~ to the last match when given no block" do
+    "z" =~ /z/ # Reset $~
+    ["abc", "def"].grep(/b/).should == ["abc"]
+
+    # Set by the failed match of "def"
+    $~.should == nil
+
+    ["abc", "def"].grep(/e/)
+    $&.should == "e"
+  end
+
   describe "with a block" do
     before :each do
       @numerous = EnumerableSpecs::Numerous.new(*(0..9).to_a)

spec/ruby/core/enumerable/grep_v_spec.rb

@@ -9,6 +9,28 @@ def (@odd_matcher = BasicObject.new).===(obj)
     end
   end
 
+  it "sets $~ in the block" do
+    "z" =~ /z/ # Reset $~
+    ["abc", "def"].grep_v(/e/) { |e|
+      e.should == "abc"
+      $~.should == nil
+    }
+
+    # Set by the match of "def"
+    $&.should == "e"
+  end
+
+  it "sets $~ to the last match when given no block" do
+    "z" =~ /z/ # Reset $~
+    ["abc", "def"].grep_v(/e/).should == ["abc"]
+
+    # Set by the match of "def"
+    $&.should == "e"
+
+    ["abc", "def"].grep_v(/b/)
+    $&.should == nil
+  end
+
   describe "without block" do
     it "returns an Array of matched elements" do
       @numerous.grep_v(@odd_matcher).should == [0, 2, 4, 6, 8]