4 files changed, 28 insertions, 10 deletions
diff --git a/spec/ruby/core/math/cos_spec.rb b/spec/ruby/core/math/cos_spec.rb
index 3ba7a54c38..006afeb2cc 100644
--- a/spec/ruby/core/math/cos_spec.rb
+++ b/spec/ruby/core/math/cos_spec.rb
@@ -15,7 +15,6 @@ describe "Math.cos" do
     Math.cos(2*Math::PI).should be_close(1.0, TOLERANCE)
   end
 
-
   it "raises a TypeError unless the argument is Numeric and has #to_f" do
     -> { Math.cos("test") }.should raise_error(TypeError)
   end
@@ -24,14 +23,23 @@ describe "Math.cos" do
     Math.cos(nan_value).nan?.should be_true
   end
 
-  it "raises a TypeError if the argument is nil" do
-    -> { Math.cos(nil) }.should raise_error(TypeError)
-  end
-
-  it "coerces its argument with #to_f" do
-    f = mock_numeric('8.2')
-    f.should_receive(:to_f).and_return(8.2)
-    Math.cos(f).should == Math.cos(8.2)
+  describe "coerces its argument with #to_f" do
+    it "coerces its argument with #to_f" do
+      f = mock_numeric('8.2')
+      f.should_receive(:to_f).and_return(8.2)
+      Math.cos(f).should == Math.cos(8.2)
+    end
+
+    it "raises a TypeError if the given argument can't be converted to a Float" do
+      -> { Math.cos(nil) }.should raise_error(TypeError)
+      -> { Math.cos(:abc) }.should raise_error(TypeError)
+    end
+
+    it "raises a NoMethodError if the given argument raises a NoMethodError during type coercion to a Float" do
+      object = mock_numeric('mock-float')
+      object.should_receive(:to_f).and_raise(NoMethodError)
+      -> { Math.cos(object) }.should raise_error(NoMethodError)
+    end
   end
 end
 
diff --git a/spec/ruby/core/math/ldexp_spec.rb b/spec/ruby/core/math/ldexp_spec.rb
index fb7799cf26..6dcf94a663 100644
--- a/spec/ruby/core/math/ldexp_spec.rb
+++ b/spec/ruby/core/math/ldexp_spec.rb
@@ -45,6 +45,12 @@ describe "Math.ldexp" do
   it "accepts any second argument that can be coerced with Integer()" do
     Math.ldexp(3.23, MathSpecs::Integer.new).should be_close(12.92, TOLERANCE)
   end
+
+  it "returns correct value that closes to the max value of double type" do
+    Math.ldexp(0.5122058490966879, 1024).should == 9.207889385574391e+307
+    Math.ldexp(0.9999999999999999, 1024).should == 1.7976931348623157e+308
+    Math.ldexp(0.99999999999999999, 1024).should == Float::INFINITY
+  end
 end
 
 describe "Math#ldexp" do
diff --git a/spec/ruby/core/math/log2_spec.rb b/spec/ruby/core/math/log2_spec.rb
index 1594f2d7af..3d4d41d130 100644
--- a/spec/ruby/core/math/log2_spec.rb
+++ b/spec/ruby/core/math/log2_spec.rb
@@ -15,7 +15,7 @@ describe "Math.log2" do
     Math.log2((2**301+45677544234809571)).should == 301.0
   end
 
-  it "raises an Errno::EDOM if the argument is less than 0" do
+  it "raises Math::DomainError if the argument is less than 0" do
     -> { Math.log2(-1e-15) }.should raise_error( Math::DomainError)
   end
 
diff --git a/spec/ruby/core/math/sqrt_spec.rb b/spec/ruby/core/math/sqrt_spec.rb
index 779aea2a0a..918e7c3a17 100644
--- a/spec/ruby/core/math/sqrt_spec.rb
+++ b/spec/ruby/core/math/sqrt_spec.rb
@@ -27,6 +27,10 @@ describe "Math.sqrt" do
   it "accepts any argument that can be coerced with Float()" do
     Math.sqrt(MathSpecs::Float.new).should be_close(1.0, TOLERANCE)
   end
+
+  it "raises a Math::DomainError when given a negative number" do
+    -> { Math.sqrt(-1) }.should raise_error(Math::DomainError)
+  end
 end
 
 describe "Math#sqrt" do