1 files changed, 39 insertions, 0 deletions
diff --git a/spec/ruby/core/fiber/new_spec.rb b/spec/ruby/core/fiber/new_spec.rb
new file mode 100644
index 0000000000..d31167496d
--- /dev/null
+++ b/spec/ruby/core/fiber/new_spec.rb
@@ -0,0 +1,39 @@
+require_relative '../../spec_helper'
+
+describe "Fiber.new" do
+  it "creates a fiber from the given block" do
+    fiber = Fiber.new {}
+    fiber.resume
+    fiber.should.instance_of?(Fiber)
+  end
+
+  it "creates a fiber from a subclass" do
+    class MyFiber < Fiber
+    end
+    fiber = MyFiber.new {}
+    fiber.resume
+    fiber.should.instance_of?(MyFiber)
+  end
+
+  it "raises an ArgumentError if called without a block" do
+    -> { Fiber.new }.should.raise(ArgumentError)
+  end
+
+  it "does not invoke the block" do
+    invoked = false
+    fiber = Fiber.new { invoked = true }
+    invoked.should == false
+    fiber.resume
+  end
+
+  it "closes over lexical environments" do
+    o = Object.new
+    def o.f
+      a = 1
+      f = Fiber.new { a = 2 }
+      f.resume
+      a
+    end
+    o.f.should == 2
+  end
+end