1 files changed, 49 insertions, 0 deletions
diff --git a/spec/ruby/shared/complex/multiply.rb b/spec/ruby/shared/complex/multiply.rb
new file mode 100644
index 0000000000..4d94ef2ce3
--- /dev/null
+++ b/spec/ruby/shared/complex/multiply.rb
@@ -0,0 +1,49 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe :complex_multiply, shared: true do
+  describe "with Complex" do
+    it "multiplies according to the usual rule for complex numbers: (a + bi) * (c + di) = ac - bd + (ad + bc)i" do
+      (Complex(1, 2) * Complex(10, 20)).should == Complex((1 * 10) - (2 * 20), (1 * 20) + (2 * 10))
+      (Complex(1.5, 2.1) * Complex(100.2, -30.3)).should == Complex((1.5 * 100.2) - (2.1 * -30.3), (1.5 * -30.3) + (2.1 * 100.2))
+    end
+  end
+
+  describe "with Integer" do
+    it "multiplies both parts of self by the given Integer" do
+      (Complex(3, 2) * 50).should == Complex(150, 100)
+      (Complex(-3, 2) * 50.5).should == Complex(-151.5, 101)
+    end
+  end
+
+  describe "with Object" do
+    it "tries to coerce self into other" do
+      value = Complex(3, 9)
+
+      obj = mock("Object")
+      obj.should_receive(:coerce).with(value).and_return([2, 5])
+      (value * obj).should == 2 * 5
+    end
+  end
+
+  describe "with a Numeric which responds to #real? with true" do
+    it "multiples both parts of self by other" do
+      other = mock_numeric('other')
+      real = mock_numeric('real')
+      imag = mock_numeric('imag')
+      other.should_receive(:real?).and_return(true)
+      real.should_receive(:*).with(other).and_return(1)
+      imag.should_receive(:*).with(other).and_return(2)
+      (Complex(real, imag) * other).should == Complex(1, 2)
+    end
+
+    describe "with a Numeric which responds to #real? with false" do
+      it "coerces the passed argument to Complex and multiplies the resulting elements" do
+        complex = Complex(3, 0)
+        other = mock_numeric('other')
+        other.should_receive(:real?).any_number_of_times.and_return(false)
+        other.should_receive(:coerce).with(complex).and_return([5, 2])
+        (complex * other).should == 10
+      end
+    end
+  end
+end