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, 61 insertions, 0 deletions

diff --git a/spec/rubyspec/core/hash/compact_spec.rb b/spec/rubyspec/core/hash/compact_spec.rb
new file mode 100644
index 0000000000..d9ef8a2987
--- /dev/null
+++ b/spec/rubyspec/core/hash/compact_spec.rb
@@ -0,0 +1,61 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+ruby_version_is "2.4" do
+  describe "Hash#compact" do
+    before :each do
+      @hash = { truthy: true, false: false, nil: nil, nil => true }
+      @initial_pairs = @hash.dup
+      @compact = { truthy: true, false: false, nil => true }
+    end
+
+    it "returns new object that rejects pair has nil value" do
+      ret = @hash.compact
+      ret.should_not equal(@hash)
+      ret.should == @compact
+    end
+
+    it "keeps own pairs" do
+      @hash.compact
+      @hash.should == @initial_pairs
+    end
+  end
+
+  describe "Hash#compact!" do
+    before :each do
+      @hash = { truthy: true, false: false, nil: nil, nil => true }
+      @initial_pairs = @hash.dup
+      @compact = { truthy: true, false: false, nil => true }
+    end
+
+    it "returns self" do
+      @hash.compact!.should equal(@hash)
+    end
+
+    it "rejects own pair has nil value" do
+      @hash.compact!
+      @hash.should == @compact
+    end
+
+    context "when each pair does not have nil value" do
+      before :each do
+        @hash.compact!
+      end
+
+      it "returns nil" do
+        @hash.compact!.should be_nil
+      end
+    end
+
+    describe "on frozen instance" do
+      before :each do
+        @hash.freeze
+      end
+
+      it "keeps pairs and raises a RuntimeError" do
+        ->{ @hash.compact! }.should raise_error(RuntimeError)
+        @hash.should == @initial_pairs
+      end
+    end
+  end
+end