1 files changed, 55 insertions, 0 deletions
diff --git a/spec/ruby/library/bigdecimal/to_f_spec.rb b/spec/ruby/library/bigdecimal/to_f_spec.rb
new file mode 100644
index 0000000000..b490fce4d9
--- /dev/null
+++ b/spec/ruby/library/bigdecimal/to_f_spec.rb
@@ -0,0 +1,55 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'bigdecimal'
+
+describe "BigDecimal#to_f" do
+  before :each do
+    @one = BigDecimal("1")
+    @zero = BigDecimal("0")
+    @zero_pos = BigDecimal("+0")
+    @zero_neg = BigDecimal("-0")
+    @two = BigDecimal("2")
+    @three = BigDecimal("3")
+    @nan = BigDecimal("NaN")
+    @infinity = BigDecimal("Infinity")
+    @infinity_minus = BigDecimal("-Infinity")
+    @one_minus = BigDecimal("-1")
+    @frac_1 = BigDecimal("1E-99999")
+    @frac_2 = BigDecimal("0.9E-99999")
+    @vals = [@one, @zero, @two, @three, @frac_1, @frac_2]
+    @spec_vals = [@zero_pos, @zero_neg, @nan, @infinity, @infinity_minus]
+  end
+
+  it "returns number of type float" do
+    BigDecimal("3.14159").to_f.should be_kind_of(Float)
+    @vals.each { |val| val.to_f.should be_kind_of(Float) }
+    @spec_vals.each { |val| val.to_f.should be_kind_of(Float) }
+  end
+
+  it "rounds correctly to Float precision" do
+    bigdec = BigDecimal("3.141592653589793238462643383279502884197169399375")
+    bigdec.to_f.should be_close(3.14159265358979, TOLERANCE)
+    @one.to_f.should == 1.0
+    @two.to_f.should == 2.0
+    @three.to_f.should be_close(3.0, TOLERANCE)
+    @one_minus.to_f.should == -1.0
+
+    # regression test for [ruby-talk:338957]
+    BigDecimal("10.03").to_f.should == 10.03
+  end
+
+  it "properly handles special values" do
+    @zero.to_f.should == 0
+    @zero.to_f.to_s.should == "0.0"
+
+    @nan.to_f.nan?.should == true
+
+    @infinity.to_f.infinite?.should == 1
+    @infinity_minus.to_f.infinite?.should == -1
+  end
+
+  it "remembers negative zero when converted to float" do
+    @zero_neg.to_f.should == 0
+    @zero_neg.to_f.to_s.should == "-0.0"
+  end
+end
+