1 files changed, 87 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerable/grep_spec.rb b/spec/ruby/core/enumerable/grep_spec.rb
new file mode 100644
index 0000000000..965e183766
--- /dev/null
+++ b/spec/ruby/core/enumerable/grep_spec.rb
@@ -0,0 +1,87 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Enumerable#grep" do
+  before :each do
+    @a = EnumerableSpecs::EachDefiner.new( 2, 4, 6, 8, 10)
+  end
+
+  it "grep without a block should return an array of all elements === pattern" do
+    class EnumerableSpecGrep; def ===(obj); obj == '2'; end; end
+
+    EnumerableSpecs::Numerous.new('2', 'a', 'nil', '3', false).grep(EnumerableSpecGrep.new).should == ['2']
+  end
+
+  it "grep with a block should return an array of elements === pattern passed through block" do
+    class EnumerableSpecGrep2; def ===(obj); /^ca/ =~ obj; end; end
+
+    EnumerableSpecs::Numerous.new("cat", "coat", "car", "cadr", "cost").grep(EnumerableSpecGrep2.new) { |i| i.upcase }.should == ["CAT", "CAR", "CADR"]
+  end
+
+  it "grep the enumerable (rubycon legacy)" do
+    EnumerableSpecs::EachDefiner.new().grep(1).should == []
+    @a.grep(3..7).should == [4,6]
+    @a.grep(3..7) {|a| a+1}.should == [5,7]
+  end
+
+  it "can use $~ in the block when used with a Regexp" do
+    ary = ["aba", "aba"]
+    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 "does not set $~ when given no block" do
+    "z" =~ /z/ # Reset $~
+    ["abc", "def"].grep(/b/).should == ["abc"]
+    $&.should == "z"
+  end
+
+  it "does not modify Regexp.last_match without block" do
+    "z" =~ /z/ # Reset last match
+    ["abc", "def"].grep(/b/).should == ["abc"]
+    Regexp.last_match[0].should == "z"
+  end
+
+  it "correctly handles non-string elements" do
+    'set last match' =~ /set last (.*)/
+    [:a, 'b', 'z', :c, 42, nil].grep(/[a-d]/).should == [:a, 'b', :c]
+    $1.should == 'match'
+
+    o = Object.new
+    def o.to_str
+      'hello'
+    end
+    [o].grep(/ll/).first.should.equal?(o)
+  end
+
+  describe "with a block" do
+    before :each do
+      @numerous = EnumerableSpecs::Numerous.new(*(0..9).to_a)
+      def (@odd_matcher = BasicObject.new).===(obj)
+        obj.odd?
+      end
+    end
+
+    it "returns an Array of matched elements that mapped by the block" do
+      @numerous.grep(@odd_matcher) { |n| n * 2 }.should == [2, 6, 10, 14, 18]
+    end
+
+    it "calls the block with gathered array when yielded with multiple arguments" do
+      EnumerableSpecs::YieldsMixed2.new.grep(Object){ |e| e }.should == EnumerableSpecs::YieldsMixed2.gathered_yields
+    end
+
+    it "raises an ArgumentError when not given a pattern" do
+      -> { @numerous.grep { |e| e } }.should.raise(ArgumentError)
+    end
+  end
+end