1 files changed, 130 insertions, 0 deletions
diff --git a/spec/ruby/core/range/minmax_spec.rb b/spec/ruby/core/range/minmax_spec.rb
new file mode 100644
index 0000000000..16c7626ea3
--- /dev/null
+++ b/spec/ruby/core/range/minmax_spec.rb
@@ -0,0 +1,130 @@
+require_relative '../../spec_helper'
+
+describe 'Range#minmax' do
+  before(:each) do
+    @x = mock('x')
+    @y = mock('y')
+
+    @x.should_receive(:<=>).with(@y).any_number_of_times.and_return(-1) # x < y
+    @x.should_receive(:<=>).with(@x).any_number_of_times.and_return(0) # x == x
+    @y.should_receive(:<=>).with(@x).any_number_of_times.and_return(1) # y > x
+    @y.should_receive(:<=>).with(@y).any_number_of_times.and_return(0) # y == y
+  end
+
+  describe 'on an inclusive range' do
+    it 'should raise RangeError on an endless range without iterating the range' do
+      @x.should_not_receive(:succ)
+
+      range = (@x..)
+
+      -> { range.minmax }.should.raise(RangeError, 'cannot get the maximum of endless range')
+    end
+
+    it 'raises RangeError or ArgumentError on a beginless range' do
+      range = (..@x)
+
+      -> { range.minmax }.should.raise(StandardError) { |e|
+        if RangeError === e
+          # error from #min
+          -> { raise e }.should.raise(RangeError, 'cannot get the minimum of beginless range')
+        else
+          # error from #max
+          -> { raise e }.should.raise(ArgumentError, 'comparison of NilClass with MockObject failed')
+        end
+      }
+    end
+
+    it 'should return beginning of range if beginning and end are equal without iterating the range' do
+      @x.should_not_receive(:succ)
+
+      (@x..@x).minmax.should == [@x, @x]
+    end
+
+    it 'should return nil pair if beginning is greater than end without iterating the range' do
+      @y.should_not_receive(:succ)
+
+      (@y..@x).minmax.should == [nil, nil]
+    end
+
+    it 'should return the minimum and maximum values for a non-numeric range without iterating the range' do
+      @x.should_not_receive(:succ)
+
+      (@x..@y).minmax.should == [@x, @y]
+    end
+
+    it 'should return the minimum and maximum values for a numeric range' do
+      (1..3).minmax.should == [1, 3]
+    end
+
+    it 'should return the minimum and maximum values for a numeric range without iterating the range' do
+      # We cannot set expectations on integers,
+      # so we "prevent" iteration by picking a value that would iterate until the spec times out.
+      range_end = Float::INFINITY
+
+      (1..range_end).minmax.should == [1, range_end]
+    end
+
+    it 'should return the minimum and maximum values according to the provided block by iterating the range' do
+      @x.should_receive(:succ).once.and_return(@y)
+
+      (@x..@y).minmax { |x, y| - (x <=> y) }.should == [@y, @x]
+    end
+  end
+
+  describe 'on an exclusive range' do
+    it 'should raise RangeError on an endless range' do
+      @x.should_not_receive(:succ)
+      range = (@x...)
+
+      -> { range.minmax }.should.raise(RangeError, 'cannot get the maximum of endless range')
+    end
+
+    it 'should raise RangeError on a beginless range' do
+      range = (...@x)
+
+      -> { range.minmax }.should.raise(RangeError,
+        /cannot get the maximum of beginless range with custom comparison method|cannot get the minimum of beginless range/)
+    end
+
+    it 'should return nil pair if beginning and end are equal without iterating the range' do
+      @x.should_not_receive(:succ)
+
+      (@x...@x).minmax.should == [nil, nil]
+    end
+
+    it 'should return nil pair if beginning is greater than end without iterating the range' do
+      @y.should_not_receive(:succ)
+
+      (@y...@x).minmax.should == [nil, nil]
+    end
+
+    it 'should return the minimum and maximum values for a non-numeric range by iterating the range' do
+      @x.should_receive(:succ).once.and_return(@y)
+
+      (@x...@y).minmax.should == [@x, @x]
+    end
+
+    it 'should return the minimum and maximum values for a numeric range' do
+      (1...3).minmax.should == [1, 2]
+    end
+
+    it 'should return the minimum and maximum values for a numeric range without iterating the range' do
+      # We cannot set expectations on integers,
+      # so we "prevent" iteration by picking a value that would iterate until the spec times out.
+      range_end = bignum_value
+
+      (1...range_end).minmax.should == [1, range_end - 1]
+    end
+
+    it 'raises TypeError if the end value is not an integer' do
+      range = (0...Float::INFINITY)
+      -> { range.minmax }.should.raise(TypeError, 'cannot exclude non Integer end value')
+    end
+
+    it 'should return the minimum and maximum values according to the provided block by iterating the range' do
+      @x.should_receive(:succ).once.and_return(@y)
+
+      (@x...@y).minmax { |x, y| - (x <=> y) }.should == [@x, @x]
+    end
+  end
+end