1 files changed, 122 insertions, 0 deletions
diff --git a/spec/ruby/core/integer/modulo_spec.rb b/spec/ruby/core/integer/modulo_spec.rb
new file mode 100644
index 0000000000..2680f49510
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+++ b/spec/ruby/core/integer/modulo_spec.rb
@@ -0,0 +1,122 @@
+require_relative '../../spec_helper'
+
+describe "Integer#%" do
+  context "fixnum" do
+    it "returns the modulus obtained from dividing self by the given argument" do
+      # test all possible combinations:
+      # - integer/double/bignum argument
+      # - positive/negative argument
+      # - positive/negative self
+      # - self greater/smaller than argument
+
+      (13 % 4).should == 1
+      (4 % 13).should == 4
+
+      (13 % 4.0).should == 1
+      (4 % 13.0).should == 4
+
+      (-200 % 256).should == 56
+      (-1000 % 512).should == 24
+
+      (-200 % -256).should == -200
+      (-1000 % -512).should == -488
+
+      (200 % -256).should == -56
+      (1000 % -512).should == -24
+
+      (13 % -4.0).should == -3.0
+      (4 % -13.0).should == -9.0
+
+      (-13 % -4.0).should == -1.0
+      (-4 % -13.0).should == -4.0
+
+      (-13 % 4.0).should == 3.0
+      (-4 % 13.0).should == 9.0
+
+      (1 % 2.0).should == 1.0
+      (200 % bignum_value).should == 200
+
+      (4 % bignum_value(10)).should == 4
+      (4 % -bignum_value(10)).should == -18446744073709551622
+      (-4 % bignum_value(10)).should == 18446744073709551622
+      (-4 % -bignum_value(10)).should == -4
+    end
+
+    it "raises a ZeroDivisionError when the given argument is 0" do
+      -> { 13 % 0  }.should.raise(ZeroDivisionError)
+      -> { 0 % 0   }.should.raise(ZeroDivisionError)
+      -> { -10 % 0 }.should.raise(ZeroDivisionError)
+    end
+
+    it "raises a ZeroDivisionError when the given argument is 0 and a Float" do
+      -> { 0 % 0.0 }.should.raise(ZeroDivisionError)
+      -> { 10 % 0.0 }.should.raise(ZeroDivisionError)
+      -> { -10 % 0.0 }.should.raise(ZeroDivisionError)
+    end
+
+    it "raises a TypeError when given a non-Integer" do
+      -> {
+        (obj = mock('10')).should_receive(:to_int).any_number_of_times.and_return(10)
+        13 % obj
+      }.should.raise(TypeError)
+      -> { 13 % "10"    }.should.raise(TypeError)
+      -> { 13 % :symbol }.should.raise(TypeError)
+    end
+  end
+
+  context "bignum" do
+    before :each do
+      @bignum = bignum_value(10)
+    end
+
+    it "returns the modulus obtained from dividing self by the given argument" do
+      # test all possible combinations:
+      # - integer/double/bignum argument
+      # - positive/negative argument
+      # - positive/negative self
+      # - self greater/smaller than argument
+
+      (@bignum % 5).should == 1
+      (@bignum % -5).should == -4
+      (-@bignum % 5).should == 4
+      (-@bignum % -5).should == -1
+
+      (@bignum % 2.22).should be_close(1.5603603603605034, TOLERANCE)
+      (@bignum % -2.22).should be_close(-0.6596396396394968, TOLERANCE)
+      (-@bignum % 2.22).should be_close(0.6596396396394968, TOLERANCE)
+      (-@bignum % -2.22).should be_close(-1.5603603603605034, TOLERANCE)
+
+      (@bignum % (@bignum + 10)).should == 18446744073709551626
+      (@bignum % -(@bignum + 10)).should == -10
+      (-@bignum % (@bignum + 10)).should == 10
+      (-@bignum % -(@bignum + 10)).should == -18446744073709551626
+
+      ((@bignum + 10) % @bignum).should == 10
+      ((@bignum + 10) % -@bignum).should == -18446744073709551616
+      (-(@bignum + 10) % @bignum).should == 18446744073709551616
+      (-(@bignum + 10) % -@bignum).should == -10
+    end
+
+    it "raises a ZeroDivisionError when the given argument is 0" do
+      -> { @bignum % 0 }.should.raise(ZeroDivisionError)
+      -> { -@bignum % 0 }.should.raise(ZeroDivisionError)
+    end
+
+    it "raises a ZeroDivisionError when the given argument is 0 and a Float" do
+      -> { @bignum % 0.0 }.should.raise(ZeroDivisionError)
+      -> { -@bignum % 0.0 }.should.raise(ZeroDivisionError)
+    end
+
+    it "raises a TypeError when given a non-Integer" do
+      -> { @bignum % mock('10') }.should.raise(TypeError)
+      -> { @bignum % "10" }.should.raise(TypeError)
+      -> { @bignum % :symbol }.should.raise(TypeError)
+    end
+  end
+end
+
+describe "Integer#modulo" do
+  it "is an alias of Integer#%" do
+    Integer.instance_method(:modulo).should == Integer.instance_method(:%)
+  end
+end