1 files changed, 23 insertions, 0 deletions
diff --git a/spec/ruby/core/set/union_spec.rb b/spec/ruby/core/set/union_spec.rb
new file mode 100644
index 0000000000..206535aae2
--- /dev/null
+++ b/spec/ruby/core/set/union_spec.rb
@@ -0,0 +1,23 @@
+require_relative '../../spec_helper'
+
+describe "Set#union" do
+  it "is an alias of Set#|" do
+    Set.instance_method(:union).should == Set.instance_method(:|)
+  end
+end
+
+describe "Set#|" do
+  before :each do
+    @set = Set[:a, :b, :c]
+  end
+
+  it "returns a new Set containing all elements of self and the passed Enumerable" do
+    (@set | Set[:b, :d, :e]).should == Set[:a, :b, :c, :d, :e]
+    (@set | [:b, :e]).should == Set[:a, :b, :c, :e]
+  end
+
+  it "raises an ArgumentError when passed a non-Enumerable" do
+    -> { @set | 1 }.should.raise(ArgumentError)
+    -> { @set | Object.new }.should.raise(ArgumentError)
+  end
+end