1 files changed, 27 insertions, 0 deletions
diff --git a/spec/ruby/core/kernel/__dir___spec.rb b/spec/ruby/core/kernel/__dir___spec.rb
new file mode 100644
index 0000000000..242adbf48b
--- /dev/null
+++ b/spec/ruby/core/kernel/__dir___spec.rb
@@ -0,0 +1,27 @@
+require_relative '../../spec_helper'
+
+describe "Kernel#__dir__" do
+  it "returns the real name of the directory containing the currently-executing file" do
+    __dir__.should == File.realpath(File.dirname(__FILE__))
+  end
+
+  it "returns the expanded path of the directory when used in the main script" do
+    fixtures_dir = File.dirname(fixture(__FILE__, '__dir__.rb'))
+    Dir.chdir(fixtures_dir) do
+      ruby_exe("__dir__.rb").should == "__dir__.rb\n#{fixtures_dir}\n"
+    end
+  end
+
+  context "when used in eval with a given filename" do
+    it "returns File.dirname(filename)" do
+      eval("__dir__", nil, "foo.rb").should == "."
+      eval("__dir__", nil, "foo/bar.rb").should == "foo"
+    end
+  end
+
+  context "when used in eval with top level binding" do
+    it "returns nil" do
+      eval("__dir__", binding).should == nil
+    end
+  end
+end