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, 50 insertions, 0 deletions

diff --git a/spec/mspec/spec/matchers/be_an_instance_of_spec.rb b/spec/mspec/spec/matchers/be_an_instance_of_spec.rb
new file mode 100644
index 0000000000..7f2126df7d
--- /dev/null
+++ b/spec/mspec/spec/matchers/be_an_instance_of_spec.rb
@@ -0,0 +1,50 @@
+require 'spec_helper'
+require 'mspec/expectations/expectations'
+require 'mspec/matchers'
+
+module BeAnInOfSpecs
+  class A
+  end
+
+  class B < A
+  end
+
+  class C < B
+  end
+end
+
+describe BeAnInstanceOfMatcher do
+  it "matches when actual is an instance_of? expected" do
+    a = BeAnInOfSpecs::A.new
+    BeAnInstanceOfMatcher.new(BeAnInOfSpecs::A).matches?(a).should be_true
+
+    b = BeAnInOfSpecs::B.new
+    BeAnInstanceOfMatcher.new(BeAnInOfSpecs::B).matches?(b).should be_true
+  end
+
+  it "does not match when actual is not an instance_of? expected" do
+    a = BeAnInOfSpecs::A.new
+    BeAnInstanceOfMatcher.new(BeAnInOfSpecs::B).matches?(a).should be_false
+
+    b = BeAnInOfSpecs::B.new
+    BeAnInstanceOfMatcher.new(BeAnInOfSpecs::A).matches?(b).should be_false
+
+    c = BeAnInOfSpecs::C.new
+    BeAnInstanceOfMatcher.new(BeAnInOfSpecs::A).matches?(c).should be_false
+    BeAnInstanceOfMatcher.new(BeAnInOfSpecs::B).matches?(c).should be_false
+  end
+
+  it "provides a useful failure message" do
+    matcher = BeAnInstanceOfMatcher.new(Numeric)
+    matcher.matches?("string")
+    matcher.failure_message.should == [
+      "Expected \"string\" (String)", "to be an instance of Numeric"]
+  end
+
+  it "provides a useful negative failure message" do
+    matcher = BeAnInstanceOfMatcher.new(Numeric)
+    matcher.matches?(4.0)
+    matcher.negative_failure_message.should == [
+      "Expected 4.0 (Float)", "not to be an instance of Numeric"]
+  end
+end