1 files changed, 42 insertions, 0 deletions
diff --git a/spec/ruby/core/regexp/last_match_spec.rb b/spec/ruby/core/regexp/last_match_spec.rb
index 6bd8f2cd90..0bfed32051 100644
--- a/spec/ruby/core/regexp/last_match_spec.rb
+++ b/spec/ruby/core/regexp/last_match_spec.rb
@@ -11,4 +11,46 @@ describe "Regexp.last_match" do
     /c(.)t/ =~ 'cat'
     Regexp.last_match(1).should == 'a'
   end
+
+  it "returns nil when there is no match" do
+    /foo/ =~ "TEST123"
+    Regexp.last_match(:test).should == nil
+    Regexp.last_match(1).should == nil
+    Regexp.last_match(Object.new).should == nil
+    Regexp.last_match("test").should == nil
+  end
+
+  describe "when given a Symbol" do
+    it "returns a named capture" do
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      Regexp.last_match(:test).should == "TEST123"
+    end
+
+    it "raises an IndexError when given a missing name" do
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      -> { Regexp.last_match(:missing) }.should raise_error(IndexError)
+    end
+  end
+
+  describe "when given a String" do
+    it "returns a named capture" do
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      Regexp.last_match("test").should == "TEST123"
+    end
+  end
+
+  describe "when given an Object" do
+    it "coerces argument to an index using #to_int" do
+      obj = mock("converted to int")
+      obj.should_receive(:to_int).and_return(1)
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      Regexp.last_match(obj).should == "TEST123"
+    end
+
+    it "raises a TypeError when unable to coerce" do
+      obj = Object.new
+      /(?<test>[A-Z]+.*)/ =~ "TEST123"
+      -> { Regexp.last_match(obj) }.should raise_error(TypeError)
+    end
+  end
 end