1 files changed, 51 insertions, 0 deletions
diff --git a/spec/ruby/core/fiber/yield_spec.rb b/spec/ruby/core/fiber/yield_spec.rb
new file mode 100644
index 0000000000..e433da0aa9
--- /dev/null
+++ b/spec/ruby/core/fiber/yield_spec.rb
@@ -0,0 +1,51 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+with_feature :fiber do
+  describe "Fiber.yield" do
+    it "passes control to the Fiber's caller" do
+      step = 0
+      fiber = Fiber.new { step = 1; Fiber.yield; step = 2; Fiber.yield; step = 3 }
+      fiber.resume
+      step.should == 1
+      fiber.resume
+      step.should == 2
+    end
+
+    it "returns its arguments to the caller" do
+      fiber = Fiber.new { true; Fiber.yield :glark; true }
+      fiber.resume.should == :glark
+      fiber.resume
+    end
+
+    it "returns nil to the caller if given no arguments" do
+      fiber = Fiber.new { true; Fiber.yield; true }
+      fiber.resume.should be_nil
+      fiber.resume
+    end
+
+    it "returns to the Fiber the value of the #resume call that invoked it" do
+      fiber = Fiber.new { Fiber.yield.should == :caller }
+      fiber.resume
+      fiber.resume :caller
+    end
+
+    it "does not propagate or reraise a rescued exception" do
+      fiber = Fiber.new do
+        begin
+          raise "an error in a Fiber"
+        rescue
+          Fiber.yield :first
+        end
+
+        :second
+      end
+
+      fiber.resume.should == :first
+      fiber.resume.should == :second
+    end
+
+    it "raises a FiberError if called from the root Fiber" do
+      lambda{ Fiber.yield }.should raise_error(FiberError)
+    end
+  end
+end