1 files changed, 24 insertions, 4 deletions
diff --git a/spec/ruby/core/env/values_at_spec.rb b/spec/ruby/core/env/values_at_spec.rb
index 906d8b01f2..ee970e5f65 100644
--- a/spec/ruby/core/env/values_at_spec.rb
+++ b/spec/ruby/core/env/values_at_spec.rb
@@ -1,17 +1,37 @@
 require_relative '../../spec_helper'
 
 describe "ENV.values_at" do
+  before :each do
+    @saved_foo = ENV["foo"]
+    @saved_bar = ENV["bar"]
+  end
+
+  after :each do
+    ENV["foo"] = @saved_foo
+    ENV["bar"] = @saved_bar
+  end
 
-  it "returns an array of the values referenced by the parameters as keys" do
+  it "returns an array of the values corresponding to the given keys" do
     ENV["foo"] = "oof"
     ENV["bar"] = "rab"
-    ENV.values_at.should == []
     ENV.values_at("bar", "foo").should == ["rab", "oof"]
-    ENV.delete "foo"
-    ENV.delete "bar"
+  end
+
+  it "returns an empty array if no keys specified" do
+    ENV.values_at.should == []
+  end
+
+  it "returns nil for each key that is not a name" do
+    ENV["foo"] = "oof"
+    ENV["bar"] = "rab"
+    ENV.values_at("x", "bar", "y", "foo", "z").should == [nil, "rab", nil, "oof", nil]
   end
 
   it "uses the locale encoding" do
     ENV.values_at(ENV.keys.first).first.encoding.should == Encoding.find('locale')
   end
+
+  it "raises TypeError when a key is not coercible to String" do
+    -> { ENV.values_at("foo", Object.new) }.should raise_error(TypeError, "no implicit conversion of Object into String")
+  end
 end