1 files changed, 43 insertions, 0 deletions
diff --git a/spec/ruby/core/float/rationalize_spec.rb b/spec/ruby/core/float/rationalize_spec.rb
new file mode 100644
index 0000000000..541080c48b
--- /dev/null
+++ b/spec/ruby/core/float/rationalize_spec.rb
@@ -0,0 +1,43 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe "Float#rationalize" do
+  it "returns self as a simplified Rational with no argument" do
+    (3382729202.92822).rationalize.should == Rational(4806858197361, 1421)
+  end
+
+  # FIXME: These specs need reviewing by somebody familiar with the
+  # algorithm used by #rationalize
+  it "simplifies self to the degree specified by a Rational argument" do
+    f = 0.3
+    f.rationalize(Rational(1,10)).should == Rational(1,3)
+    f.rationalize(Rational(-1,10)).should == Rational(1,3)
+
+    f = -f
+    f.rationalize(Rational(1,10)).should == Rational(-1,3)
+    f.rationalize(Rational(-1,10)).should == Rational(-1,3)
+
+  end
+
+  it "simplifies self to the degree specified by a Float argument" do
+    f = 0.3
+    f.rationalize(0.05).should == Rational(1,3)
+    f.rationalize(0.001).should == Rational(3, 10)
+
+    f = -f
+    f.rationalize(0.05).should == Rational(-1,3)
+    f.rationalize(0.001).should == Rational(-3,10)
+  end
+
+  it "raises a FloatDomainError for Infinity" do
+    lambda {infinity_value.rationalize}.should raise_error(FloatDomainError)
+  end
+
+  it "raises a FloatDomainError for NaN" do
+    lambda { nan_value.rationalize }.should raise_error(FloatDomainError)
+  end
+
+  it "raises ArgumentError when passed more than one argument" do
+    lambda { 0.3.rationalize(0.1, 0.1) }.should raise_error(ArgumentError)
+    lambda { 0.3.rationalize(0.1, 0.1, 2) }.should raise_error(ArgumentError)
+  end
+end