1 files changed, 37 insertions, 0 deletions
diff --git a/spec/ruby/core/math/exp_spec.rb b/spec/ruby/core/math/exp_spec.rb
new file mode 100644
index 0000000000..a727404462
--- /dev/null
+++ b/spec/ruby/core/math/exp_spec.rb
@@ -0,0 +1,37 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Math.exp" do
+  it "returns a float" do
+    Math.exp(1.0).should be_kind_of(Float)
+  end
+
+  it "returns the base-e exponential of the argument" do
+    Math.exp(0.0).should == 1.0
+    Math.exp(-0.0).should == 1.0
+    Math.exp(-1.8).should be_close(0.165298888221587, TOLERANCE)
+    Math.exp(1.25).should be_close(3.49034295746184, TOLERANCE)
+  end
+
+  it "raises a TypeError if the argument cannot be coerced with Float()" do
+    lambda { Math.exp("test") }.should raise_error(TypeError)
+  end
+
+  it "returns NaN given NaN" do
+    Math.exp(nan_value).nan?.should be_true
+  end
+
+  it "raises a TypeError if the argument is nil" do
+    lambda { Math.exp(nil) }.should raise_error(TypeError)
+  end
+
+  it "accepts any argument that can be coerced with Float()" do
+    Math.exp(MathSpecs::Float.new).should be_close(Math::E, TOLERANCE)
+  end
+end
+
+describe "Math#exp" do
+  it "is accessible as a private instance method" do
+    IncludesMath.new.send(:exp, 23.1415).should be_close(11226018484.0012, TOLERANCE)
+  end
+end