Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 69 insertions, 0 deletions

diff --git a/spec/rubyspec/core/integer/downto_spec.rb b/spec/rubyspec/core/integer/downto_spec.rb
new file mode 100644
index 0000000000..6b7b353760
--- /dev/null
+++ b/spec/rubyspec/core/integer/downto_spec.rb
@@ -0,0 +1,69 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe "Integer#downto [stop] when self and stop are Fixnums" do
+  it "does not yield when stop is greater than self" do
+    result = []
+    5.downto(6) { |x| result << x }
+    result.should == []
+  end
+
+  it "yields once when stop equals self" do
+    result = []
+    5.downto(5) { |x| result << x }
+    result.should == [5]
+  end
+
+  it "yields while decreasing self until it is less than stop" do
+    result = []
+    5.downto(2) { |x| result << x }
+    result.should == [5, 4, 3, 2]
+  end
+
+  it "yields while decreasing self until it less than ceil for a Float endpoint" do
+    result = []
+    9.downto(1.3) {|i| result << i}
+    3.downto(-1.3) {|i| result << i}
+    result.should == [9, 8, 7, 6, 5, 4, 3, 2, 3, 2, 1, 0, -1]
+  end
+
+  it "raises an ArgumentError for invalid endpoints" do
+    lambda {1.downto("A") {|x| p x } }.should raise_error(ArgumentError)
+    lambda {1.downto(nil) {|x| p x } }.should raise_error(ArgumentError)
+  end
+
+  describe "when no block is given" do
+    it "returns an Enumerator" do
+      result = []
+
+      enum = 5.downto(2)
+      enum.each { |i| result << i }
+
+      result.should == [5, 4, 3, 2]
+    end
+
+    describe "returned Enumerator" do
+      describe "size" do
+        it "raises an ArgumentError for invalid endpoints" do
+          enum = 1.downto("A")
+          lambda { enum.size }.should raise_error(ArgumentError)
+          enum = 1.downto(nil)
+          lambda { enum.size }.should raise_error(ArgumentError)
+        end
+
+        it "returns self - stop + 1" do
+          10.downto(5).size.should == 6
+          10.downto(1).size.should == 10
+          10.downto(0).size.should == 11
+          0.downto(0).size.should == 1
+          -3.downto(-5).size.should == 3
+        end
+
+        it "returns 0 when stop > self" do
+          4.downto(5).size.should == 0
+          -5.downto(0).size.should == 0
+          -5.downto(-3).size.should == 0
+        end
+      end
+    end
+  end
+end