1 files changed, 112 insertions, 0 deletions
diff --git a/spec/ruby/library/bigdecimal/sqrt_spec.rb b/spec/ruby/library/bigdecimal/sqrt_spec.rb
new file mode 100644
index 0000000000..f677192b33
--- /dev/null
+++ b/spec/ruby/library/bigdecimal/sqrt_spec.rb
@@ -0,0 +1,112 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+require 'bigdecimal'
+
+describe "BigDecimal#sqrt" do
+  before :each do
+    @one = BigDecimal("1")
+    @zero = BigDecimal("0")
+    @zero_pos = BigDecimal("+0")
+    @zero_neg = BigDecimal("-0")
+    @two = BigDecimal("2.0")
+    @three = BigDecimal("3.0")
+    @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")
+  end
+
+  it "returns square root of 2 with desired precision" do
+    string = "1.41421356237309504880168872420969807856967187537694807317667973799073247846210703885038753432764157"
+    (1..99).each { |idx|
+      @two.sqrt(idx).should be_close(BigDecimal(string), BigDecimal("1E-#{idx-1}"))
+    }
+  end
+
+  it "returns square root of 3 with desired precision" do
+    sqrt_3 = "1.732050807568877293527446341505872366942805253810380628055806979451933016908800037081146186757248575"
+    (1..99).each { |idx|
+      @three.sqrt(idx).should be_close(BigDecimal(sqrt_3), BigDecimal("1E-#{idx-1}"))
+    }
+  end
+
+  it "returns square root of 121 with desired precision" do
+    BigDecimal('121').sqrt(5).should be_close(11, 0.00001)
+  end
+
+  it "returns square root of 0.9E-99999 with desired precision" do
+    @frac_2.sqrt(1).to_s.should =~ /\A0\.3E-49999\z/i
+  end
+
+  it "raises ArgumentError when no argument is given" do
+    lambda {
+      @one.sqrt
+    }.should raise_error(ArgumentError)
+  end
+
+  it "raises ArgumentError if a negative number is given" do
+    lambda {
+      @one.sqrt(-1)
+    }.should raise_error(ArgumentError)
+  end
+
+  it "raises ArgumentError if 2 arguments are given" do
+    lambda {
+      @one.sqrt(1, 1)
+    }.should raise_error(ArgumentError)
+  end
+
+  it "raises TypeError if nil is given" do
+    lambda {
+      @one.sqrt(nil)
+    }.should raise_error(TypeError)
+  end
+
+  it "raises TypeError if a string is given" do
+    lambda {
+      @one.sqrt("stuff")
+    }.should raise_error(TypeError)
+  end
+
+  it "raises TypeError if a plain Object is given" do
+    lambda {
+      @one.sqrt(Object.new)
+    }.should raise_error(TypeError)
+  end
+
+  it "returns 1 if precision is 0 or 1" do
+    @one.sqrt(1).should == 1
+    @one.sqrt(0).should == 1
+  end
+
+  it "raises FloatDomainError on negative values" do
+    lambda {
+      BigDecimal('-1').sqrt(10)
+    }.should raise_error(FloatDomainError)
+  end
+
+  it "returns positive infitinity for infinity" do
+    @infinity.sqrt(1).should == @infinity
+  end
+
+  it "raises FloatDomainError for negative infinity" do
+    lambda {
+      @infinity_minus.sqrt(1)
+    }.should raise_error(FloatDomainError)
+  end
+
+  it "raises FloatDomainError for NaN" do
+    lambda {
+      @nan.sqrt(1)
+    }.should raise_error(FloatDomainError)
+  end
+
+  it "returns 0 for 0, +0.0 and -0.0" do
+    @zero.sqrt(1).should == 0
+    @zero_pos.sqrt(1).should == 0
+    @zero_neg.sqrt(1).should == 0
+  end
+
+end