1 files changed, 39 insertions, 0 deletions
diff --git a/spec/ruby/core/env/key_spec.rb b/spec/ruby/core/env/key_spec.rb
new file mode 100644
index 0000000000..677cf35216
--- /dev/null
+++ b/spec/ruby/core/env/key_spec.rb
@@ -0,0 +1,39 @@
+require_relative '../../spec_helper'
+require_relative 'shared/include'
+
+describe "ENV.key?" do
+  it_behaves_like :env_include, :key?
+end
+
+describe "ENV.key" do
+  before :each do
+    @saved_foo = ENV["foo"]
+  end
+
+  after :each do
+    ENV["foo"] = @saved_foo
+  end
+
+  it "returns the index associated with the passed value" do
+    ENV["foo"] = "bar"
+    ENV.key("bar").should == "foo"
+  end
+
+  it "returns nil if the passed value is not found" do
+    ENV.delete("foo")
+    ENV.key("foo").should == nil
+  end
+
+  it "coerces the key element with #to_str" do
+    ENV["foo"] = "bar"
+    k = mock('key')
+    k.should_receive(:to_str).and_return("bar")
+    ENV.key(k).should == "foo"
+  end
+
+  it "raises TypeError if the argument is not a String and does not respond to #to_str" do
+    -> {
+      ENV.key(Object.new)
+    }.should.raise(TypeError, "no implicit conversion of Object into String")
+  end
+end