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, 28 insertions, 0 deletions

diff --git a/spec/mspec/lib/mspec/matchers/signed_zero.rb b/spec/mspec/lib/mspec/matchers/signed_zero.rb
new file mode 100644
index 0000000000..3fd1472fc8
--- /dev/null
+++ b/spec/mspec/lib/mspec/matchers/signed_zero.rb
@@ -0,0 +1,28 @@
+class SignedZeroMatcher
+  def initialize(expected_sign)
+    @expected_sign = expected_sign
+  end
+
+  def matches?(actual)
+    @actual = actual
+    (1.0/actual).infinite? == @expected_sign
+  end
+
+  def failure_message
+    ["Expected #{@actual}", "to be #{"-" if @expected_sign == -1}0.0"]
+  end
+
+  def negative_failure_message
+    ["Expected #{@actual}", "not to be #{"-" if @expected_sign == -1}0.0"]
+  end
+end
+
+class Object
+  def be_positive_zero
+    SignedZeroMatcher.new(1)
+  end
+
+  def be_negative_zero
+    SignedZeroMatcher.new(-1)
+  end
+end