1 files changed, 80 insertions, 0 deletions
diff --git a/spec/ruby/language/throw_spec.rb b/spec/ruby/language/throw_spec.rb
new file mode 100644
index 0000000000..d78c137708
--- /dev/null
+++ b/spec/ruby/language/throw_spec.rb
@@ -0,0 +1,80 @@
+require File.expand_path('../../spec_helper', __FILE__)
+
+describe "The throw keyword" do
+  it "abandons processing" do
+    i = 0
+    catch(:done) do
+      loop do
+        i += 1
+        throw :done if i > 4
+      end
+      i += 1
+    end
+    i.should == 5
+  end
+
+  it "supports a second parameter" do
+    msg = catch(:exit) do
+      throw :exit,:msg
+    end
+    msg.should == :msg
+  end
+
+  it "uses nil as a default second parameter" do
+    msg = catch(:exit) do
+      throw :exit
+    end
+    msg.should == nil
+  end
+
+  it "clears the current exception" do
+    catch :exit do
+      begin
+        raise "exception"
+      rescue
+        throw :exit
+      end
+    end
+    $!.should be_nil
+  end
+
+  it "allows any object as its argument" do
+    catch(1) { throw 1, 2 }.should == 2
+    o = Object.new
+    catch(o) { throw o, o }.should == o
+  end
+
+  it "does not convert strings to a symbol" do
+    lambda { catch(:exit) { throw "exit" } }.should raise_error(ArgumentError)
+  end
+
+  it "unwinds stack from within a method" do
+    def throw_method(handler, val)
+      throw handler, val
+    end
+
+    catch(:exit) do
+      throw_method(:exit, 5)
+    end.should == 5
+  end
+
+  it "unwinds stack from within a lambda" do
+    c = lambda { throw :foo, :msg }
+    catch(:foo) { c.call }.should == :msg
+  end
+
+  it "raises an ArgumentError if outside of scope of a matching catch" do
+    lambda { throw :test, 5 }.should raise_error(ArgumentError)
+    lambda { catch(:different) { throw :test, 5 } }.should raise_error(ArgumentError)
+  end
+
+  it "raises an ArgumentError if used to exit a thread" do
+    lambda {
+      catch(:what) do
+        Thread.new {
+          throw :what
+        }.join
+      end
+    }.should raise_error(ArgumentError)
+  end
+end