1 files changed, 32 insertions, 3 deletions
diff --git a/spec/ruby/core/env/shared/select.rb b/spec/ruby/core/env/shared/select.rb
index a0b46a775a..8ec648a637 100644
--- a/spec/ruby/core/env/shared/select.rb
+++ b/spec/ruby/core/env/shared/select.rb
@@ -1,16 +1,38 @@
 describe :env_select, shared: true do
+  before :each do
+    @saved_foo = ENV["foo"]
+  end
+
+  after :each do
+    ENV["foo"] = @saved_foo
+  end
+
   it "returns a Hash of names and values for which block return true" do
     ENV["foo"] = "bar"
     (ENV.send(@method) { |k, v| k == "foo" }).should == { "foo" => "bar" }
-    ENV.delete "foo"
   end
 
   it "returns an Enumerator when no block is given" do
-    ENV.send(@method).should be_an_instance_of(Enumerator)
+    enum = ENV.send(@method)
+    enum.should.instance_of?(Enumerator)
+  end
+
+  it "selects via the enumerator" do
+    enum = ENV.send(@method)
+    ENV["foo"] = "bar"
+    enum.each { |k, v| k == "foo" }.should == { "foo" => "bar"}
   end
 end
 
 describe :env_select!, shared: true do
+  before :each do
+    @saved_foo = ENV["foo"]
+  end
+
+  after :each do
+    ENV["foo"] = @saved_foo
+  end
+
   it "removes environment variables for which the block returns true" do
     ENV["foo"] = "bar"
     ENV.send(@method) { |k, v| k != "foo" }
@@ -27,6 +49,13 @@ describe :env_select!, shared: true do
   end
 
   it "returns an Enumerator if called without a block" do
-    ENV.send(@method).should be_an_instance_of(Enumerator)
+    ENV.send(@method).should.instance_of?(Enumerator)
+  end
+
+  it "selects via the enumerator" do
+    enum = ENV.send(@method)
+    ENV["foo"] = "bar"
+    enum.each { |k, v| k != "foo" }
+    ENV["foo"].should == nil
   end
 end