add core/fixnum/multiply spec

test/test-android/app/core/fixnum/multiply_spec.rb

@@ -0,0 +1,41 @@
+class Core_Fixnum_Multiply_Mock1 < Java::Lang::Object
+  def to_int
+    10
+  end
+end
+
+describe "Fixnum#*" do
+  it "returns self multiplied by the given Integer" do
+    (4923 * 2).should == 9846
+    (1342177 * 800).should == 1073741600
+    (65536 * 65536).should == 4294967296
+
+    (256 * bignum_value).should == 2361183241434822606848
+    (6712 * 0.25).should == 1678.0
+  end
+
+  it "raises a TypeError when given a non-Integer" do
+    lambda {
+      obj = Core_Fixnum_Multiply_Mock1.new
+      13 * obj
+    }.should raise_error(TypeError)
+    lambda { 13 * "10"    }.should raise_error(TypeError)
+    lambda { 13 * :symbol }.should raise_error(TypeError)
+  end
+
+  it "overflows to Bignum when the result does not fit in Fixnum" do
+    if 1.size == 4
+      # 32-bit fixnums
+      y = 0x4000
+      result = y * y * y
+      result.should == 0x40000000000
+      result.should be_kind_of(Bignum)
+    elsif 1.size == 8
+      # 64-bit fixnums
+      y = 0x40000000
+      result = y * y * y
+      result.should == 0x40000000000000000000000
+      result.should be_kind_of(Bignum)
+    end
+  end
+end