1 files changed, 32 insertions, 0 deletions
diff --git a/spec/ruby/core/env/include_spec.rb b/spec/ruby/core/env/include_spec.rb
new file mode 100644
index 0000000000..8e68aa3bfd
--- /dev/null
+++ b/spec/ruby/core/env/include_spec.rb
@@ -0,0 +1,32 @@
+require_relative '../../spec_helper'
+
+describe "ENV.include?" do
+  before :each do
+    @saved_foo = ENV["foo"]
+  end
+
+  after :each do
+    ENV["foo"] = @saved_foo
+  end
+
+  it "returns true if ENV has the key" do
+    ENV["foo"] = "bar"
+    ENV.include?( "foo").should == true
+  end
+
+  it "returns false if ENV doesn't include the key" do
+    ENV.delete("foo")
+    ENV.include?( "foo").should == false
+  end
+
+  it "coerces the key with #to_str" do
+    ENV["foo"] = "bar"
+    k = mock('key')
+    k.should_receive(:to_str).and_return("foo")
+    ENV.include?( k).should == true
+  end
+
+  it "raises TypeError if the argument is not a String and does not respond to #to_str" do
+    -> { ENV.include?( Object.new) }.should.raise(TypeError, "no implicit conversion of Object into String")
+  end
+end