1 files changed, 48 insertions, 0 deletions
diff --git a/spec/ruby/core/math/asin_spec.rb b/spec/ruby/core/math/asin_spec.rb
new file mode 100644
index 0000000000..1386bccc06
--- /dev/null
+++ b/spec/ruby/core/math/asin_spec.rb
@@ -0,0 +1,48 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+# arcsine : (-1.0, 1.0) --> (-PI/2, PI/2)
+describe "Math.asin" do
+  it "returns a float" do
+    Math.asin(1).should.is_a?(Float)
+  end
+
+  it "returns the arcsine of the argument" do
+    Math.asin(1).should be_close(Math::PI/2, TOLERANCE)
+    Math.asin(0).should be_close(0.0, TOLERANCE)
+    Math.asin(-1).should be_close(-Math::PI/2, TOLERANCE)
+    Math.asin(0.25).should be_close(0.252680255142079, TOLERANCE)
+    Math.asin(0.50).should be_close(0.523598775598299, TOLERANCE)
+    Math.asin(0.75).should be_close(0.8480620789814816,TOLERANCE)
+  end
+
+  it "raises an Math::DomainError if the argument is greater than 1.0" do
+    -> { Math.asin(1.0001) }.should.raise( Math::DomainError)
+  end
+
+  it "raises an Math::DomainError if the argument is less than -1.0" do
+    -> { Math.asin(-1.0001) }.should.raise( Math::DomainError)
+  end
+
+  it "raises a TypeError if the argument cannot be coerced with Float()" do
+    -> { Math.asin("test") }.should.raise(TypeError)
+  end
+
+  it "returns NaN given NaN" do
+    Math.asin(nan_value).nan?.should == true
+  end
+
+  it "raises a TypeError if the argument is nil" do
+    -> { Math.asin(nil) }.should.raise(TypeError)
+  end
+
+  it "accepts any argument that can be coerced with Float()" do
+    Math.asin(MathSpecs::Float.new).should be_close(1.5707963267949, TOLERANCE)
+  end
+end
+
+describe "Math#asin" do
+  it "is accessible as a private instance method" do
+    IncludesMath.new.send(:asin, 0.5).should be_close(0.523598775598299, TOLERANCE)
+  end
+end