1 files changed, 21 insertions, 0 deletions
diff --git a/spec/ruby/library/prime/instance_spec.rb b/spec/ruby/library/prime/instance_spec.rb
new file mode 100644
index 0000000000..64497c1b7c
--- /dev/null
+++ b/spec/ruby/library/prime/instance_spec.rb
@@ -0,0 +1,21 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'prime'
+
+describe "Prime.instance" do
+  it "returns a object representing the set of prime numbers" do
+    Prime.instance.should be_kind_of(Prime)
+  end
+
+  it "returns a object with no obsolete features" do
+    Prime.instance.should_not respond_to(:succ)
+    Prime.instance.should_not respond_to(:next)
+  end
+
+  it "does not complain anything" do
+    lambda { Prime.instance }.should_not complain
+  end
+
+  it "raises a ArgumentError when is called with some arguments" do
+    lambda { Prime.instance(1) }.should raise_error(ArgumentError)
+  end
+end