1 files changed, 27 insertions, 0 deletions
diff --git a/spec/ruby/core/math/cbrt_spec.rb b/spec/ruby/core/math/cbrt_spec.rb
new file mode 100644
index 0000000000..4e2383043b
--- /dev/null
+++ b/spec/ruby/core/math/cbrt_spec.rb
@@ -0,0 +1,27 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Math.cbrt" do
+  it "returns a float" do
+    Math.cbrt(1).should.instance_of?(Float)
+  end
+
+  it "returns the cubic root of the argument" do
+    Math.cbrt(1).should == 1.0
+    Math.cbrt(8.0).should == 2.0
+    Math.cbrt(-8.0).should == -2.0
+    Math.cbrt(3).should be_close(1.44224957030741, TOLERANCE)
+  end
+
+  it "raises a TypeError if the argument cannot be coerced with Float()" do
+    -> { Math.cbrt("foobar") }.should.raise(TypeError)
+  end
+
+  it "raises a TypeError if the argument is nil" do
+    -> { Math.cbrt(nil) }.should.raise(TypeError)
+  end
+
+  it "accepts any argument that can be coerced with Float()" do
+    Math.cbrt(MathSpecs::Float.new).should be_close(1.0, TOLERANCE)
+  end
+end